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Träfflista för sökning "WFRF:(Kvarnemo Charlotta 1963) "

Sökning: WFRF:(Kvarnemo Charlotta 1963)

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1.
  • Lindsay, Willow, 1980, et al. (författare)
  • Endless forms of sexual selection
  • 2019
  • Ingår i: PeerJ. - : PeerJ. - 2167-8359. ; 7
  • Tidskriftsartikel (refereegranskat)abstract
    • In recent years, the field of sexual selection has exploded, with advances in theoretical and empirical research complementing each other in exciting ways. This perspective piece is the product of a "stock-taking'' workshop on sexual selection and sexual conflict. Our aim is to identify and deliberate on outstanding questions and to stimulate discussion rather than provide a comprehensive overview of the entire field. These questions are organized into four thematic sections we deem essential to the field. First we focus on the evolution of mate choice and mating systems. Variation in mate quality can generate both competition and choice in the opposite sex, with implications for the evolution of mating systems. Limitations on mate choice may dictate the importance of direct vs. indirect benefits in mating decisions and consequently, mating systems, especially with regard to polyandry. Second, we focus on how sender and receiver mechanisms shape signal design. Mediation of honest signal content likely depends on integration of temporally variable social and physiological costs that are challenging to measure. We view the neuroethology of sensory and cognitive receiver biases as the main key to signal form and the 'aesthetic sense' proposed by Darwin. Since a receiver bias is sufficient to both initiate and drive ornament or armament exaggeration, without a genetically correlated or even coevolving receiver, this may be the appropriate 'null model' of sexual selection. Thirdly, we focus on the genetic architecture of sexually selected traits. Despite advances in modern molecular techniques, the number and identity of genes underlying performance, display and secondary sexual traits remains largely unknown. In-depth investigations into the genetic basis of sexual dimorphism in the context of long-term field studies will reveal constraints and trajectories of sexually selected trait evolution. Finally, we focus on sexual selection and conflict as drivers of speciation. Population divergence and speciation are often influenced by an interplay between sexual and natural selection. The extent to which sexual selection promotes or counteracts population divergence may vary depending on the genetic architecture of traits as well as the covariance between mating competition and local adaptation. Additionally, post-copulatory processes, such as selection against heterospecific sperm, may influence the importance of sexual selection in speciation. We propose that efforts to resolve these four themes can catalyze conceptual progress in the field of sexual selection, and we offer potential avenues of research to advance this progress.
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2.
  • Ah-King, M., et al. (författare)
  • The influence of territoriality and mating system on the evolution of male care: a phylogenetic study on fish.
  • 2005
  • Ingår i: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 18:2, s. 371-382
  • Tidskriftsartikel (refereegranskat)abstract
    • Evolution of male care is still poorly understood. Using phylogenetically matched-pairs comparisons we tested for effects of territoriality and mating system on male care evolution in fish. All origins of male care were found in pair-spawning species (with or without additional males such as sneakers) and none were found in group-spawning species. However, excluding group spawners, male care originated equally often in pair-spawning species with additional males as in strict pair-spawning species. Evolution of male care was also significantly related to territoriality. Yet, most pair-spawning taxa with male care are also territorial, making their relative influence difficult to separate. Furthermore, territoriality also occurs in group-spawning species. Hence, territoriality is not sufficient for male care to evolve. Rather, we argue that it is the combination of territoriality and pair spawning with sequential polygyny that favours the evolution of male care, and we discuss our results in relation to paternity assurance and sexual selection.
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3.
  • Ah-King, M., et al. (författare)
  • Why is there no sperm competition in a pipefish with externally brooding males? Insights from sperm activation and morphology
  • 2006
  • Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 68:3, s. 958-962
  • Tidskriftsartikel (refereegranskat)abstract
    • Nerophis ophidion sperm activation and morphology were investigated with the aim of explaining the apparent lack of sperm competition in this syngnathid with externally brooding males. Nerophis ophidion sperm were activated by a mixture of ovarian fluid and sea water, but not by sea water alone. This indicated that sperm were not shed into the water but needed to be released near the eggs, which probably restrained sperm competition. (c) 2006 The Fisheries Society of the British Isles.
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4.
  • Ahnesjö, Ingrid, et al. (författare)
  • Variation in sexual selection in fishes
  • 2008
  • Ingår i: Fish Behaviour (Eds. Magnhagen, C., Braithwaite, V. A., Forsgren, E. & B. G. Kapoor). - Enfield, N.H. : Science Publishers (USA). - 9781578084357
  • Bokkapitel (övrigt vetenskapligt/konstnärligt)
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5.
  • Andrén, Maria Norevik, 1970, et al. (författare)
  • Filial cannibalism in a nest-guarding fish: females prefer to spawn in nests with few eggs over many
  • 2014
  • Ingår i: Behavioral Ecology and Sociobiology. - : Springer Science and Business Media LLC. - 0340-5443 .- 1432-0762. ; 68:10, s. 1565-1576
  • Tidskriftsartikel (refereegranskat)abstract
    • In fish, fecundity correlates with female body size and egg-tending males often eat small broods. Therefore, small females may prefer to spawn in nests that already contain many eggs, to ensure the brood is as large as possible. In contrast, large females may prefer nests with few eggs, if high egg number or density has a negative effect on egg survival, or if there are drawbacks of spawning last in a nest. To test the hypothesis that female body size affects nest (and male mate) choice, using the sand goby (Pomatoschistus minutus), we allowed small and large females to choose between two males that were matched in size—one guarding a small clutch and the other a large clutch, respectively. We recorded where females spawned (measure of female preference), the combined brood size, male courtship, egg care and nest building. We also quantified the effect of brood size and egg density on egg survival in a separate data set. Although the combined broods did not exceed the small brood sizes that are at risk of being eaten, both small and large females preferred to spawn in nests with smaller clutch sizes. This preference could not be explained by more courtship or male parental effort, nor by reduced survival of larger or denser broods. Instead, our result might be explained by females avoiding the danger of cannibalism of young eggs by males or the risk of reduced egg health associated with being near the nest periphery.
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6.
  • Asnicar, Davide, et al. (författare)
  • Sand Goby : An Ecologically Relevant Species for Behavioural Ecotoxicology
  • 2018
  • Ingår i: Fishes. - : MDPI. - 2410-3888. ; 3:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Locomotion-based behavioural endpoints have been suggested as suitable sublethal endpoints for human and environmental hazard assessment, as well as for biomonitoring applications. Larval stages of the sand goby (Pomatoschistus minutus) possess a number of attractive qualities for experimental testing that make it a promising species in behavioural ecotoxicology. Here, we present a study aimed at developing a toolkit for using the sand goby as novel species for ecotoxicological studies and using locomotion as an alternative endpoint in toxicity testing. Exposure to three contaminants (copper (Cu), di-butyl phthalate (DBP) and perfluorooctanoic acid (PFOA) was tested in the early life stages of the sand goby and the locomotion patterns of the larvae were quantified using an automatic tracking system. In a photo-motor test, sand goby larvae displayed substantially higher activity in light than in dark cycles. Furthermore, all tested compounds exerted behavioural alterations, such as hypo- and hyperactivity. Our experimental results show that sand goby larvae produce robust and quantifiable locomotive responses, which could be used within an ecotoxicological context for assessing the behavioural toxicity of environmental pollutants, with particular relevance in the Nordic region. This study thus suggests that sand goby larvae have potential as an environmentally relevant species for behavioural ecotoxicology, and as such offer an alternative to standard model species.
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7.
  • Björk, Johannes R., et al. (författare)
  • Mechanisms behind size-assortative nest choice by sand goby males in absence of intrasexual competition
  • 2012
  • Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 83:1, s. 55-62
  • Tidskriftsartikel (refereegranskat)abstract
    • Among nest-holding !sh, males often choose nest sites according to their own body size (i.e. size-assortative nest choice). In most cases, this can be explained by intrasexual competition. However, a few studies, for example on a marine population of the sand goby, Pomatoschistus minutus, have found a size-assortative nest preference, even when intrasexual competition is excluded. We conducted three aquarium experiments, using small sand goby males (47e54 mm) that were given either small (size-matched) or large (size-mismatched) nest sites, to test for potential mechanisms underlying this size-assortative nest choice in the absence of intrasexual competition. The three mechanisms investigated were (1) female preference, (2) paternal expenditure and (3) nest take-over. We did not, however, !nd any !tness advantages for sizematched males in any of the three experiments, suggesting that some other mechanism, such as defence against egg predators, is underlying this particular behaviour. Thus, further studies are needed to explain size-assortative nest choice behaviour in the sand goby.
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8.
  • Blom, Eva-Lotta, 1973, et al. (författare)
  • Continuous but not intermittent noise has a negative impact on mating success in a marine fish with paternal care
  • 2019
  • Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9
  • Tidskriftsartikel (refereegranskat)abstract
    • Anthropogenic underwater noise is a global pollutant of increasing concern but its impact on reproduction in fish is largely unknown. Hence, a better understanding of its consequences for this important link to fitness is crucial. Working in aquaria, we experimentally tested the impact of broadband noise exposure (added either continuously or intermittently), compared to a control, on the behaviour and reproductive success of the common goby (Pomatoschistus microps), a vocal fish with exclusive paternal care. Compared to the intermittent noise and control treatments, the continuous noise treatment increased latency to female nest inspection and spawning and decreased spawning probability. In contrast, many other female and male pre-spawning behaviours, and female ventilation rate (proxies for stress levels) did not differ among treatments. Therefore, it is likely that female spawning decisions were delayed by a reduced ability to assess male acoustic signals, rather than due to stress per se and that the silent periods in the intermittent noise treatment provided a respite where the females could assess the males. Taken together, we show that noise (of similar frequency range as anthropogenic boat noise) negatively affects reproductive success, particularly under a continuous noise exposure.
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9.
  • Blom, Eva-Lotta, 1973, et al. (författare)
  • Male acoustic display in the sand goby – Essential cue in female choice, but unaffected by supplemental feeding
  • 2022
  • Ingår i: Journal of Experimental Marine Biology and Ecology. - : Elsevier. - 0022-0981 .- 1879-1697. ; 556
  • Tidskriftsartikel (refereegranskat)abstract
    • Many teleost fishes use acoustic and visual signalling during courtship. Such displays may convey information about body condition. Here we experimentally altered body condition of sand goby (Pomatoschistus minutus) males to examine effects on acoustic and visual courtship and subsequent spawning decisions. Over two weeks, males fed in excess were fed daily, whereas food-deprived males were fed once a week. Females only spawned with males that produced courtship sound. However, there were no treatment effects on the occurrence of spawning and males fed in excess did not invest more in visual or acoustic courtship than food-deprived males. That said, males fed in excess built more well-covered nests, with more sand piled on top, compared to food-deprived males. Male condition measured as lipid content differed significantly between treatments. However, only males fed in excess differed in lipid content from wild caught males, indicating that in nature, males are of similar condition to males in the low condition treatment group. Apart from the importance of courtship sound, the only male or female behaviour predicting reproductive success was if male displayed in the nest opening. Males often produce courtship sounds together with a visual display in this position. A female dark-eye display did not associate with reproductive success which, together with previous results, suggest a non-ornamental function of this trait. We conclude that male courtship sounds appear to be crucial in female mate choice, but the information content of the courtship sounds and how it relates to male condition remains elusive.
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10.
  • Braga Gonçalves, Inês, et al. (författare)
  • Effects of female mating order and male size on embryo survival in a pipefish.
  • 2015
  • Ingår i: Biological Journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4066 .- 1095-8312. ; 114:3, s. 639-645
  • Tidskriftsartikel (refereegranskat)abstract
    • In species that provide parental care, individuals should invest adaptively in their offspring in relation to the preand post-zygotic care provided by their partners. In the broad-nosed pipefish, Syngnathus typhle L., females transfer large, nutrient-rich eggs into the male brood pouch during mating. The male broods and nourishes the embryos for several weeks before independent juveniles emerge at parturition. Given a choice, females clearly prefer large partners. Yet, females provide protein-richer eggs when the same individual mates with a smaller than a larger male. In the present study, we allowed each female to mate with one small and one large male, in alternated order. We found a strong effect of female mating order, with larger clutches and higher embryo mortality in first- than second-laid broods, which may suggest that eggs over-ripen in the ovaries or reflect the negative effects of high embryo density in the brood pouch. In either case, this effect should put constraints on the possibility of a female being selective in mate choice. We also found that small and large males produced embryos of similar size and survival, consistent with the reproductive compensation hypothesis, suggesting that, in this species, larger males provide better nourishment to the embryos than smaller males.
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11.
  • Braga Gonçalves, Inês, et al. (författare)
  • Embryo oxygenation in pipefish brood pouches: novel insights
  • 2015
  • Ingår i: Journal of Experimental Biology. - : The Company of Biologists. - 0022-0949 .- 1477-9145. ; 218:11, s. 1639-1646
  • Tidskriftsartikel (refereegranskat)abstract
    • The pipefish brood pouch presents a unique mode of parental care that enables males to protect, osmoregulate, nourish and oxygenate the developing young. Using a very fine O-2 probe, we assessed the extent to which males of the broad-nosed pipefish (Syngnathus typhle) oxygenate the developing embryos and are able to maintain pouch fluid O-2 levels when brooding in normoxia (100% O-2 saturation) and hypoxia (40% O-2 saturation) for 24 days. In both treatments, pouch fluid-O-2 saturation levels were lower compared with the surrounding water and decreased throughout the brooding period, reflecting greater offspring demand for O-2 during development and/or decreasing paternal ability to provide O-2 to the embryos. Male condition (hepatosomatic index) was negatively affected by hypoxia. Larger males had higher pouch fluid O-2 saturation levels compared with smaller males, and levels were higher in the bottom section of the pouch compared with other sections. Embryo size was positively correlated with O-2 availability, irrespective of their position in the pouch. Two important conclusions can be drawn from our findings. First, our results highlight a potential limitation to brooding within the pouch and dismiss the notion of closed brood pouches as well-oxygenated structures promoting the evolution of larger eggs in syngnathids. Second, we provide direct evidence that paternal care improves with male size in this species. This finding offers an explanation for the documented strong female preference for larger partners because, in terms of oxygenation, the brood pouch can restrict embryo growth.
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12.
  • Braga Gonçalves, Inês, et al. (författare)
  • Evolutionary ecology of pipefish brooding structures: embryo survival and growth do not improve with a pouch
  • 2016
  • Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 6:11, s. 3608-3620
  • Tidskriftsartikel (refereegranskat)abstract
    • For animals that reproduce in water, many adaptations in life-history traits such as egg size, parental care, and behaviors that relate to embryo oxygenation are still poorly understood. In pipefishes, seahorses and seadragons, males care for the embryos either in some sort of brood pouch, or attached ventrally to the skin on their belly or tail. Typically, egg size is larger in the brood pouch group and it has been suggested that oxygen supplied via the pouch buffers the developing embryos against hypoxia and as such is an adaptation that has facilitated the evolution of larger eggs. Here, using four pipefish species, we tested whether the presence or absence of brood pouch relates to how male behavior, embryo size, and survival are affected by hypoxia, with normoxia as control. Two of our studied species Entelurus aequoreus and Nerophis ophidion (both having small eggs) have simple ventral attachment of eggs onto the male trunk, and the other two, Syngnathus typhle (large eggs) and S. rostellatus (small eggs), have fully enclosed brood pouches on the tail. Under hypoxia, all species showed lower embryo survival, while species with brood pouches suffered greater embryo mortality compared to pouchless species, irrespective of oxygen treatment. Behaviorally, species without pouches spent more time closer to the surface, possibly to improve oxygenation. Overall, we found no significant benefits of brood pouches in terms of embryo survival and size under hypoxia. Instead, our results suggest negative effects of large egg size, despite the protection of brood pouches.
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13.
  • Braga Gonçalves, Inês, et al. (författare)
  • The evolutionary puzzle of egg size, oxygenation and parental care in aquatic environments
  • 2015
  • Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 282:1813
  • Tidskriftsartikel (refereegranskat)abstract
    • Offspring fitness generally improves with increasing egg size.Yet, eggs of most aquatic organisms are small. A common but largely untested assumption is that larger embryos require more oxygen than they can acquire through diffusion via the egg surface, constraining egg size evolution. However, we found no detrimental effects of large egg size on embryo growth and survival under hypoxic conditions. We tested this in the broad-nosed pipefish, Syngnathus typhle, whose males provide extensive care (nourishment, osmoregulation and oxygenation) to their young in a brood pouch on their bodies. We took advantage of this species’ pronounced variation in egg size, correlating positively with female size, and tested the effect of hypoxia (40% dissolved oxygen) versus fully oxygenated (100%) water on embryo size and survival of large versus small eggs after 18 days of paternal brooding. Egg size did not affect embryo survival, regardless of O2 treatment. While hypoxia affected embryo size negatively, both large and small eggs showed similar reductions in growth. Males in hypoxia ventilated more and males with large eggs swam more, but neither treatment affected their position in the water column. Overall, our results call into question the most common explanation for constrained egg size evolution in aquatic environments.
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14.
  • García-Berro, Aurora, et al. (författare)
  • Understanding resource driven female-female competition: ovary and liver size in sand gobies
  • 2019
  • Ingår i: Royal Society Open Science. - : The Royal Society. - 2054-5703. ; 6:9
  • Tidskriftsartikel (refereegranskat)abstract
    • The operational sex ratio (OSR, ready-to-mate males to females) is a key factor determining mating competition. A shortage of a resource essential for reproduction of one sex can affect OSR and lead to competition within the opposite sex for resource-holding mates. In the sand goby (Pomatoschistus minutus), a fish with paternal care, male readiness to mate depends on acquiring a nest-site, whereas food abundance primarily impacts female egg production. Comparing body condition and gonadal investment of fish from two populations with different availability in resources (Baltic Sea: few nest-sites, more food; North Sea: many nest-sites, less food), we predicted females carrying more mature eggs in the Baltic Sea than in the North Sea. As predicted, ovaries were larger in Baltic Sea females, and so was the liver (storage of energy reserves and vitellogenic compounds) for both sexes, but particularly for females. More females were judged (based on roundness scores) to be ready to spawn in the Baltic Sea. Together with a nest colonization experiment confirming a previously documented difference between the two areas in nest-site availability, these results indicate a more female-biased OSR in the Baltic Sea population, compared to the North Sea, and generates a prediction that female-female competition for mating opportunities is stronger in the Baltic population. To our knowledge, this is the first time that female reproductive investment is discussed in relation to OSR using field data.
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15.
  • Goncalves, Ines, 1982, et al. (författare)
  • Effects of egg size and moderate hypoxia on the development and survival of Syngnathus typhle embryos
  • 2008
  • Ingår i: International Society for Behavioral Ecology, Ithaca, USA, 2008.
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Even though offspring quality generally improves with increasing egg size, eggs of aquatic organisms never get as big as eggs of for example birds or reptiles do. A very common assumption is that above a certain size, embryos require more oxygen than they can acquire by diffusion through the egg surface and therefore cannot develop. Oxygen demands of embryos are thought to increase in accordance with egg volume whilst oxygen availability is restricted by the surface area of the egg. Therefore, large eggs have a comparatively small surface area to volume ratio than smaller eggs have, suggesting that egg size may be constrained by oxygen limitations. Despite being widely accepted, this assumption has seldom been tested. In the broad-nosed pipefish, Syngnathus typhle, egg size is positively correlated with female length, so that females of different size classes produce eggs of significantly different diameters. In this study, we tested the effect of moderate hypoxia (40% O2) on the survival and development of embryos from large and small eggs, after 18 days of brooding. Results show that under hypoxia, initial egg size does not affect either survival or development. Hypoxia in itself negatively affected embryonic development but not survival. Moreover, embryos developed significantly larger vitelline membranes, which improve oxygen uptake, under hypoxic conditions. Taken together, development but not survival of S. typhle embryos was affected by hypoxia, and, despite the significant difference in egg size within this species, no detrimental effects of egg size were observed under hypoxic conditions.
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16.
  • Goncalves, Ines, 1982, et al. (författare)
  • MATERNAL ALLOCATION OF RESOURCES INTO THE EGGS IN RELATION TO PARTNER SIZE IN THE
  • 2007
  • Ingår i: European Society for Evolutionary Biology, Uppsala, 2007.
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Animals that reproduce more than once are expected to make adaptive decisions on how much to invest in each reproductive event. According to the Differential Allocation hypothesis, organisms should weigh the costs and benefits of investing into reproduction when mating with their current partner against the possibility of finding higher quality mates in the future. In the pipefish Syngnathus typhle, males care for the young in a brood pouch. Both sexes prefer large-sized mates, generating a size assortative mating pattern. Females are polyandrous and hence commonly transfer eggs to several males during each breeding season. Large males produce larger offspring than small males do, but it is unknown whether this is due solely to large males gaining access to larger females, which produce larger eggs, or if it is generated (or reinforced) by females investing more into their eggs when mating with a large male. Conversely, females might invest more into the eggs when having to mate with a small male, especially if such males provide poorer care to the eggs than large males do. This study assessed whether females show differential allocation, and whether they allocate more or less resources to the eggs, depending on the size of their mate. We let each female mate with a large and a small male, and measured diameter, weight, lipid and protein content of the eggs. Our results show that females did not invest more into the eggs when mating with a large male. Instead, the egg protein content was higher when females mated with small males, indicating a compensatory differential allocation.
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17.
  • Goncalves, Ines, 1982, et al. (författare)
  • Reproductive compensation in broad-nosed pipefish females : Reproductive compensation in a pipefish
  • 2010
  • Ingår i: Proceedings of the Royal Society B. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 277, s. 1581-1589
  • Tidskriftsartikel (refereegranskat)abstract
    • The differential allocation hypothesis assumes that animals should weigh costs and benefits of investing into reproduction with a current mate against the expected quality of future mates, and predicts that they should invest more into reproduction when pairing with a high-quality mate. In the broad-nosed pipefish (Syngnathus typhle), males care for the embryos in a brood pouch and females compete for access to male mating partners. Both sexes prefer mating with large partners. In the present study, we show that the same female provides both large and small mating partners with eggs of similar size, weight and lipid content when mated to two males in succession. Importantly, however, eggs provided to small males (less preferred) had higher egg protein content (11% more) than those provided to large males (preferred). Thus, contrary to the differential allocation hypothesis, eggs did not contain more resources when females mated with a larger male. Instead, the pattern observed in our results is consistent with a compensatory reproductive strategy.
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18.
  • Goncalves, Ines, 1982, et al. (författare)
  • Syngnathus typhle females strategically allocate resources to offspring
  • 2008
  • Ingår i: Evolution of Parental Effects: Conceptual Issues and Empirical Patterns, Wollongong, 2008.
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Animals that reproduce more than once are expected to make adaptive decisions on how much to invest in each reproductive event. According to the Differential Allocation hypothesis, organisms should weigh the costs and benefits of investing into reproduction when mating with their current partner against the possibility of finding higher quality mates in the future. In the pipefish Syngnathus typhle, males care for the young in a brood pouch. Both sexes prefer large-sized mates, generating a size assortative mating pattern. Females are polyandrous and hence commonly transfer eggs to several males during each breeding season. Large males produce larger offspring than small males do, but it is unknown whether this is due solely to large males gaining access to larger females, which produce larger eggs, or if it is generated (or reinforced) by females investing more into their eggs when mating with a large male. Conversely, females might invest more into the eggs when having to mate with a small male, especially if such males provide poorer care to the eggs than large males do. This study assessed whether females show differential allocation, and whether they allocate more or less resources to the eggs, depending on the size of their mate. We let each female mate with a large and a small male, and measured diameter, weight, lipid and protein content of the eggs. Our results show that females did not invest more into the eggs when mating with a large male. Instead, the egg protein content was higher when females mated with small males, indicating a compensatory differential allocation.
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19.
  • Goncalves, Ines, 1982, et al. (författare)
  • The relationship between female body size and egg size in pipefishes
  • 2011
  • Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 78:6, s. 1847-1854
  • Tidskriftsartikel (refereegranskat)abstract
    • Comparing five species of pipefish, egg size was significantly larger in species with brood pouches (Syngnathus typhle, Syngnathus acus and Syngnathus rostellatus) than in species without brood pouches (Entelurus aequoreus and Nerophis ophidion). Egg size correlated positively with female body size in species with brood pouches, but was similar across female sizes in the species lacking pouches. These results may reflect differences in offspring competition as a consequence of variable offspring relatedness within a brood, due to the mating systems adopted by the different species and the presence or absence of a brood pouch.
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20.
  • Green, Leon, et al. (författare)
  • Alternative reproductive tactics are associated with sperm performance in invasive round goby from two different salinity environments
  • 2020
  • Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 10:18, s. 9981-9999
  • Tidskriftsartikel (refereegranskat)abstract
    • During male–male competition, evolution can favor alternative reproductive tactics. This often results in a dominant morph that holds a resource, such as a nest for egg laying, which competes with a smaller sneaker morph that reproduces by stealing fertilizations. The salinity environment can influence male growth rates, for example, via osmoregulatory costs, which in turn may influence the use of sneaker tactics for small males competing for mating opportunities. Salinity can also affect sperm directly; however, little is known of how salinity influences sneaker tactics through sperm performance. We sampled males of the invasive round goby (Neogobius melanostomus) from two environments, a freshwater river and a brackish estuary. This fish has two male morphs: nest‐holding dark males and non‐nest‐holding light males. We examined the role of water salinity of 0, 8, and 16 on sperm performance and found that for estuarine males, a salinity of 0 reduced sperm velocity compared to a salinity of 8 and 16. Riverine males had low velocity in all salinities. Sperm viability also decreased by over 30% in 0 salinity, compared to 8 and 16, for fish from both environments. Gobies produce ejaculate contents in specialized glands that could in theory shield sperm in an adverse environment. However, gland contents did not improve sperm performance in our tests. Body mass and age estimates indicate that riverine males invested more in somatic growth compared to estuarine males. Estuarine light morph males had a high enough gonadosomatic index to indicate sneaker tactics. We propose that when sperm performance is low, such as for the riverine males, sneaker tactics are ineffective and will be selected against or phenotypically suppressed. Instead, we interpret the increased investment in somatic growth found in riverine males as a life‐history decision that is advantageous when defending a nest in the next reproductive season.
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21.
  • Green, Leon, et al. (författare)
  • Ancestral Sperm Ecotypes Reveal Multiple Invasions of a Non-Native Fish in Northern Europe
  • 2021
  • Ingår i: Cells. - : MDPI AG. - 2073-4409. ; 10:7
  • Tidskriftsartikel (refereegranskat)abstract
    • For externally fertilising organisms in the aquatic environment, the abiotic fertilisation medium can be a strong selecting force. Among bony fishes, sperm are adapted to function in a narrow salinity range. A notable exception is the family Gobiidae, where several species reproduce across a wide salinity range. The family also contains several wide-spread invasive species. To better understand how these fishes tolerate such varying conditions, we measured sperm performance in relation to salinity from a freshwater and a brackish population within their ancestral Ponto-Caspian region of the round goby, Neogobius melanostomus. These two ancestral populations were then compared to nine additional invaded sites across northern Europe, both in terms of their sperm traits and by using genomic SNP markers. Our results show clear patterns of ancestral adaptations to freshwater and brackish salinities in their sperm performance. Population genomic analyses show that the ancestral ecotypes have generally established themselves in environments that fit their sperm adaptations. Sites close to ports with intense shipping show that both outbreeding and admixture can affect the sperm performance of a population in a given salinity. Rapid adaptation to local conditions is also supported at some sites. Historical and contemporary evolution in the traits of the round goby sperm cells is tightly linked to the population and seascape genomics as well as biogeographic processes in these invasive fishes. Since the risk of a population establishing in an area is related to the genotype by environment match, port connectivity and the ancestry of the round goby population can likely be useful for predicting the species spread.
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22.
  • Green, Leon, et al. (författare)
  • Evidence of rapid adaptive trait change to local salinity in the sperm of an invasive fish
  • 2020
  • Ingår i: Evolutionary Applications. - : Wiley. - 1752-4571. ; 13:3, s. 533-544
  • Tidskriftsartikel (refereegranskat)abstract
    • Invasive species may quickly colonize novel environments, which could be attributed to both phenotypic plasticity and an ability to locally adapt. Reproductive traits are expected to be under strong selection when the new environment limits reproductive success of the invading species. This may be especially important for external fertilizers, which release sperm and eggs into the new environment. Despite adult tolerance to high salinity, the invasive fish Neogobius melanostomus (round goby) is absent from fully marine regions of the Baltic Sea, raising the possibility that its distribution is limited by tolerance during earlier life stages. Here, we investigate the hypothesis that the spread of N. melanostomus is limited by sperm function in novel salinities. We sampled sperm from two invasion fronts with higher and lower salinities in the Baltic Sea and tested them across a range of salinity levels. We found that sperm velocity and percentage of motile sperm declined in salinity levels higher and lower than those currently experienced by the Baltic Sea populations, with different performance curves for the two fronts. Sperm velocity also peaked closer to the home salinity conditions in each respective invasion front, with older localities showing an increased fit to local conditions. By calculating how the sperm velocity has changed over generations, we show this phenotypic shift to be in the range of other fish species under strong selection, indicating ongoing local adaptation or epigenetic acclimation to their novel environment. These results show that while immigrant reproductive dysfunction appears to at least partly limit the distribution of invasive N. melanostomus in the Baltic Sea, local adaptation to novel environments could enable future spread beyond their current boundaries.
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23.
  • Green, Leon, et al. (författare)
  • Invader at the edge - Genomic origins and physiological differences of round gobies across a steep urban salinity gradient
  • 2023
  • Ingår i: Evolutionary Applications. - : Wiley. - 1752-4571. ; 16:2, s. 321-37
  • Tidskriftsartikel (refereegranskat)abstract
    • Species invasions are a global problem of increasing concern, especially in highly connected aquatic environments. Despite this, salinity conditions can pose physiological barriers to their spread, and understanding them is important for management. In Scandinavia's largest cargo port, the invasive round goby (Neogobius melanostomus) is established across a steep salinity gradient. We used 12,937 SNPs to identify the genetic origin and diversity of three sites along the salinity gradient and round goby from western, central and northern Baltic Sea, as well as north European rivers. Fish from two sites from the extreme ends of the gradient were also acclimated to freshwater and seawater, and tested for respiratory and osmoregulatory physiology. Fish from the high-salinity environment in the outer port showed higher genetic diversity, and closer relatedness to the other regions, compared to fish from lower salinity upstream the river. Fish from the high-salinity site also had higher maximum metabolic rate, fewer blood cells and lower blood Ca2+. Despite these genotypic and phenotypic differences, salinity acclimation affected fish from both sites in the same way: seawater increased the blood osmolality and Na+ levels, and freshwater increased the levels of the stress hormone cortisol. Our results show genotypic and phenotypic differences over short spatial scales across this steep salinity gradient. These patterns of the physiologically robust round goby are likely driven by multiple introductions into the high-salinity site, and a process of sorting, likely based on behaviour or selection, along the gradient. This euryhaline fish risks spreading from this area, and seascape genomics and phenotypic characterization can inform management strategies even within an area as small as a coastal harbour inlet.
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24.
  • Green, Leon, et al. (författare)
  • Sperm-duct gland content increases sperm velocity in the sand goby
  • 2019
  • Ingår i: Biology Open. - : The Company of Biologists. - 2046-6390. ; 8
  • Tidskriftsartikel (refereegranskat)abstract
    • Sperm performance is often tightly linked to male reproductive success. In many demersal gobiid fishes, the male attaches sperm embedded in a mucus produced by sperm-duct glands to the nest substrate before spawning takes place. Sperm are activated as the mucus and embedded gland content dissolve into the water. To test the importance of gland content on sperm function in Pomatoschistus minutus, a marine fish with external fertilization, we used a paired experimental design, with spermatozoa tested with and without sperm-duct gland content mixed into seawater. We measured sperm velocity, percentage of motile sperm and sperm viability over time. Sperm were found to swim 7.3% faster when gland content was mixed in the seawater. Percentage motile sperm was unaffected by the gland content. Sperm viability in seawater exceeded 24 h, but was unaffected by the gland content. An increase in sperm velocity of similar magnitude as found here has been shown by others to increase fertilization success. Since velocity-boosting properties of sperm-duct gland content have now been found in three distantly related goby species, this trait appears to be conserved across the Gobiidae family and may aid in reproduction across a range of species and environments.
  •  
25.
  • Green, Leon, et al. (författare)
  • Sperm performance limits the reproduction of an invasive fish in novel salinities
  • 2021
  • Ingår i: Diversity and Distributions. - : Wiley. - 1366-9516 .- 1472-4642. ; 27:6, s. 1091-1105
  • Tidskriftsartikel (refereegranskat)abstract
    • Aim: The few fish species able to reproduce across wide osmotic ranges either plastically acclimate sperm performance to, or are locally adapted to, different salinities. The invasive round goby (Neogobius melanostomus) is spreading in Eurasia and the Americas, into both fresh and brackish water. We aim to understand if reproduction in different salinities is affected by an ability to acclimate. Location: Brackish and freshwater systems of northern Europe and the Baltic Sea. Methods: We cross-exposed round gobies of freshwater and brackish origin to 0 and 16 practical salinity units (PSU), and the fish were given nest boxes in which to spawn. After 4weeks, we measured their sperm performance in both 0 and 16 PSU; fertilization success of each egg clutch was measured through visual analysis of eggs. Clutches were split and allowed to develop in both 0 and 16 PSU salinity, and reproductive success (zygote development) was measured 20±1days later. Responses were analysed using generalized mixed models. Results: After a month, the fish showed no plasticity in sperm performance to their acclimation salinity, regardless of their origin. Sperm velocity was highest in the salinity similar to the males’ origin. Significantly lower fertilization success was measured for individuals that reproduced outside their salinity of origin despite recurring spawning events in all treatment groups. Among fertilized eggs, zygote development was similar regardless of salinity treatment of either eggs or parents. Main Conclusions: Short-term acclimation to new salinities does not affect sperm performance in the round goby. Alternative hypotheses such as local adaption should be further investigated. Limits to the species’ reproductive success, and therefore invasion processes, are likely dependent on environment-phenotype matches. Fish of brackish origin spawned successfully in freshwater, pointing to an increased risk of introducing populations of brackish origin into freshwater.
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26.
  • Gustavsson, Susanne, 1957, et al. (författare)
  • Lärande för hållbar utveckling i yrkeslärarutbildning : Learning for sustainable development in vocational teacher education
  • 2018
  • Ingår i: Nordic Journal of Vocational Education and Training. - 2242-458X. ; 8:3, s. 19-35
  • Tidskriftsartikel (refereegranskat)abstract
    • This article draws on data from a module on education for sustainable development (ESD) in vocational teacher education. There are two kinds of data: 47 group work projects, where the assignment was to design an ESD activity in upper secondary vocational education, and a web questionnaire (average response rate of 80 %). The purpose is to describe and discuss how ESD can take form in vocational teacher education, and how the students value the knowledge that they have acquired when working with the module. The results give a positive picture of many different pedagogical approaches of planning an ESD activity. The variety of the contents of the activities stretch from having specific vocational focus, to broader societal perspectives. The planned activities for the pupils also differ, from participating in classroom exercises to activities based on actionand student-based planning. The different pedagogical approaches are exemplified and discussed. The results from the questionnaire show that over all, the students are positive to the content of the ESD module and the work that is carried out within this part of the course. These results are related to previous studies with critical aspects of teaching ESD.
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27.
  • Henning Loeb, Ingrid, 1962, et al. (författare)
  • Enabling action-oriented and transformative learning for sustainability in vocational teacher education. Example from The University of Gothenburg, Sweden
  • 2016
  • Ingår i: AARE Conference, Melbourne. 28/11-1/12, 2016.
  • Konferensbidrag (refereegranskat)abstract
    • Sustainable development has been a theme in the vocational teacher education at the University of Gothenburg, Sweden, since autumn 2013. It is organized as part of a 7.5 credit course on evaluation and development work in schools. 30% of this course has a focus on sustainable development and this educational unit is provided by researchers and teacher from the Department of Biological and Environmental Sciences. The purpose of this unit is aligned with the dimensions of Educational Sustainable Development (ESD), put forth by Unesco. It addresses learning content on sustainable development in schools and the students are provided pedagogical models for ESD. In this paper, we present the content and form of this educational unit, analyse the pedagogical models that the students have worked. This is carried out as group project for two weeks, where they plan how a ESD task could be carried out in their specific VET program in Upper secondary education. In the end of the paper, we also reflect on the results provided by the student course evaluations that we have received since 2013 (student evaluations from eight semesters). We argue that the model enables action-oriented and transformative learning for sustainability. Vocational teacher education is Sweden is provided as a 90 ECTS credits programme: 60 credits of course-based studies and 30 credits of work-based training (practicum) in upper secondary schools or adult education. This can be arranged as full-time studies of one-and-a-half-year, or part-time studies. At the University of Gothenburg, the arrangement is a three-year part-time study program, mostly distance-based with some on-campus meetings at the university. Most of the students (75-80%) work as unqualified teachers in upper secondary education and in adult education. The average number of students per semester is 30. Thus, more than 200 vocational teacher students have participated in this course, and provide data presented in the paper.
  •  
28.
  • Johannesson, Kerstin, 1955, et al. (författare)
  • Non-random paternity of offspring in a highly promiscuous marine snail suggests postcopulatory sexual selection
  • 2016
  • Ingår i: Behavioral Ecology and Sociobiology. - : Springer Science and Business Media LLC. - 0340-5443 .- 1432-0762. ; 70:8, s. 1357-1366
  • Tidskriftsartikel (refereegranskat)abstract
    • In the marine snail Littorina saxatilis females are highly polyandrous, resulting in simultaneous broods of offspring sired by similar to 20 males. Such high polyandry, in combination with female sperm storage, is likely to promote postcopulatory sexual selection among males. In addition, females may gain direct reproductive benefits from multiple mating. Investigating sexual selection in males and female benefits in relation to the number of sires, we put single virgin females in aquaria with one, two, five or ten males for 80 days, during which each female mated a majority of available males. After removal of the males, females continued to produce offspring during > 1 year. Offspring genotypes of 27 families showed multiple paternity with 76 % of males contributing to juveniles, but paternity deviated from random with one or a few males siring the majority of the offspring. Larger males tended to be overrepresented among the sires. Female reproductive output (newborn or juvenile stage) did, however, not increase with number of sires, and females seemed not limited by the number of available males. Because previous studies have shown that females are seemingly indiscriminative in their mate choice, and given that they mate many hundreds of times in their lifespan, this suggests there is comparatively limited scope for premating sexual selection in this species. Hence, we interpret these results mainly in the light of postcopulatory sexual selection. Sexual selection is a main component of evolution. In that context, mating behaviour is central, although it sometimes appears puzzling, even maladaptive. For example, matings are costly; still, in some species, females mate multiple times and with numerous males. Why this behaviour has evolved is intriguing. Extensive numbers of matings suggest less efficient precopulatory mate choice, opening for postcopulatory sexual selection through cryptic female choice and sperm competition. Using a highly promiscuous snail species with internal fertilisation and long-term sperm storage, we identified the fathers of 549 offspring. We found that while females mated most males available, the offspring were non-randomly distributed among mated males and large males were overrepresented among the sires. This suggests that sexual selection predominantly occurs after mating and that males benefit from size-related effects. Yet, we could not find any female benefits from mating multiple males.
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29.
  • Johannesson, Kerstin, 1955, et al. (författare)
  • Ten years of marine evolutionary biology - challenges and achievements of a multidisciplinary research initiative
  • 2023
  • Ingår i: Evolutionary Applications. - : Wiley. - 1752-4571. ; 16:2, s. 530-41
  • Tidskriftsartikel (refereegranskat)abstract
    • The Centre for Marine Evolutionary Biology (CeMEB) at the University of Gothenburg, Sweden, was established in 2008 through a 10-year research grant of 8.7 m€ to a team of senior researchers. Today, CeMEB members have contributed >500 scientific publications, 30 PhD theses and have organised 75 meetings and courses, including 18 three-day meetings and four conferences. What are the footprints of CeMEB, and how will the centre continue to play a national and international role as an important node of marine evolutionary research? In this perspective arcticle we first look back over the 10 years of CeMEB activities and briefly survey some of the many achievements of CeMEB. We furthermore compare the initial goals, as formulated in the grant application, with what has been achieved, and discuss challenges and milestones along the way. Finally, we bring forward some general lessons that can be learnt from a research funding of this type, and we take also look ahead, discussing how CeMEB’s achievements and lessons can be used as a springboard to the future of marine evolutionary biology.
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30.
  • Järvi-Laturi, Maria, et al. (författare)
  • Sand goby males trade off between defence against egg predators and sneak intrusions
  • 2011
  • Ingår i: Journal of Zoology. - : Wiley. - 0952-8369 .- 1469-7998. ; 283:4, s. 269-275
  • Tidskriftsartikel (refereegranskat)abstract
    • According to life-history theory, a care-taking parent should balance investment in current and future reproduction in such a way that it maximizes lifetime reproductive success. In the sand goby Pomatoschistus minutus, a small marine fish with paternal care, nest-guarding males may lose current reproductive success to both parasitically fertilizing males and egg predators. Here, we observed sand gobies at a marine and a brackish site, two geographically distant and ecologically different habitats. In a field experiment, we found that sand gobies at the marine site suffered from severe egg predation by netted dogwhelks Nassarius nitidus, which are lacking at the brackish site. Because egg laying takes hours and several females often lay eggs sequentially in one nest, the risk of parasitic spawnings and egg predation overlaps in time during breeding activities. Hypothesizing that egg predators might influence the success of parasitic spawnings, we then simulated these natural conditions in a laboratory experiment with the presence or absence of egg predators, combined with the presence of sneaker males. As expected, in the egg predator treatment, egg-guarding males had to compromise between defence behaviours and thus had less time to devote to defence against sneaker males. Sneaker males took advantage of the situation and approached the nests more actively than in the predator-free treatment. However, the increase in approaches did not result in more successful parasitic fertilizations by sneaker males, as determined using microsatellite DNA. Nevertheless, in nature the adjustment of time budgets by the egg-guarding male are likely to have serious fitness consequences, both if the male fails to defend his paternity and if he fails to defend his offspring.
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31.
  • Kvarnemo, Charlotta, 1963, et al. (författare)
  • Evidence of paternal nutrient provisioning to embryos in the pipefish Syngnathus typhle
  • 2011
  • Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112. ; 78:6, s. 1725-1737
  • Tidskriftsartikel (refereegranskat)abstract
    • In two experiments, radioactively labelled nutrients (either 3H-labelled amino-acid mixture or 14Clabelled glucose) were tube-fed to brooding male Syngnathus typhle. Both nutrients were taken up by the males and radioactivity generally increased in the brood pouch tissue with time. Furthermore, a low but significant increase of 3H-labelled amino acids in embryos was found over the experimental interval (48 h), whereas in the 14C-glucose experiment the radioactivity was taken up by the embryos but did not increase over the experimental time (320 min). Uptake of radioisotopes per embryo did not differ with embryo size. A higher uptake mg−1 tissue of both 3H-labelled amino acids and 14C-labelled glucose was found in smaller embryos, possibly due to a higher relative metabolic rate or to a higher surface-area-to-volume ratio compared to larger embryos. Uptake in embryos was not influenced by male size, embryonic developmental advancement or position in the brood pouch. It is concluded that brooding males provide amino acids, and probably also glucose, to the developing embryos in the brood pouch.
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32.
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33.
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34.
  • Kvarnemo, Charlotta, 1963, et al. (författare)
  • Gravida hanar och konkurrerande honor
  • 2014
  • Ingår i: Havsutsikt. - 1104-0513. ; 2014:1, s. 6-7
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • Hos fisken tångsnälla blir pappan gravid. Hanen förser ungarna med syre och näring under utvecklingen, men han kan också själv ta upp näring som kommer från äggen. Honor konkurrerar om att få para sig med hanar som har plats för hennes ägg, och de gillar särskilt att para sig med stora hanar. Trots det ger de ägg med mer näring till små hanar.
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35.
  • Kvarnemo, Charlotta, 1963, et al. (författare)
  • Home range use in the West Australian seahorse Hippocampus subelongatus is influenced by sex and partner's home range but not by body size or paired status
  • 2021
  • Ingår i: Journal of Ethology. - : Springer Science and Business Media LLC. - 0289-0771 .- 1439-5444. ; 39:2, s. 235-48
  • Tidskriftsartikel (refereegranskat)abstract
    • Genetic monogamy is the rule for many species of seahorse, including the West Australian seahorse Hippocampus subelongatus. In this paper, we revisit mark-recapture and genetic data of H. subelongatus, allowing a detailed characterization of movement distances, home range sizes and home range overlaps for each individual of known sex, paired status (paired or unpaired) and body size. As predicted, we find that females have larger home ranges and move greater distances compared to males. We also confirm our prediction that the home ranges of pair-bonded individuals (members of a pair known to reproduce together) overlap more on average than home ranges of randomly chosen individuals of the opposite or same sex. Both sexes, regardless of paired status, had home ranges that overlapped with, on average, 6-10 opposite-sex individuals. The average overlap area among female home ranges was significantly larger than the overlap among male home ranges, probably reflecting females having larger home ranges combined with a female biased adult sex ratio. Despite a prediction that unpaired individuals would need to move around to find a mate, we find no evidence that unpaired members of either sex moved more than paired individuals of the same sex. We also find no effect of body size on home range size, distance moved or number of other individuals with which a home range overlapped. These patterns of movement and overlap in home ranges among individuals of both sexes suggest that low mate availability is not a likely explanation for the maintenance of monogamy in the West Australian seahorse.
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36.
  • Kvarnemo, Charlotta, 1963, et al. (författare)
  • Investment in testes, sperm-duct glands and lipid reserves differs between male morphs but not between early and late breeding season in Pomatoschistus minutus
  • 2010
  • Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 76:7, s. 1609-1625
  • Tidskriftsartikel (refereegranskat)abstract
    • This study of the sand goby Pomatoschistus minutus, a nest-holding fish with paternal care, focused on gonadal investment among males of different sizes collected early and late in the breeding season. All males caught at the nest had breeding colour, whereas trawl-caught fish consisted of males both with and without colour. The absence or presence of breeding colour was a good predictor of testes investment. Compared to males with breeding colour, males without colour were smaller in body size but had extraordinarily large testes. In absolute terms, testes mass of males without breeding colour was on average 3.4 times greater than those of males with breeding colour. Since small colourless males are known to reproduce as sneaker males, this heavy investment in testes probably reflects that they are forced to spawn under sperm competition. Contrary to testes size, sperm-duct glands were largest among males with breeding colour. These glands produce mucins used for making sperm-containing mucous trails that males place in the nest before and during spawning. Since both sneakers and nest-holders potentially could benefit from having large glands, this result is intriguing. Yet, high mucus production may be more important for nest-holders, because it also protects developing embryos from infections. There was no significant effect of season on body size, testes or sperm-duct glands size, but colourless males tended to be less common late in the season. Possibly this may indicate that individual small colourless males develop into their more colourful counterparts within the breeding season.
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37.
  • Kvarnemo, Charlotta, 1963, et al. (författare)
  • Mating distribution and its temporal dynamics affect operational sex ratio: a simulation study
  • 2006
  • Ingår i: Biological Journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4066. ; 89:3, s. 551-559
  • Tidskriftsartikel (refereegranskat)abstract
    • The present study investigated how variation in mating distribution in time and among males influences the operational sex ratio (OSR) with a simulation inspired by paternally caring fish. Varying (1) the potential reproductive rate of each sex, (2) the mating distribution among males, and (3) the length of male mating phase, we created different mating patterns. In each case, we searched for the adult sex ratio that resulted in an OSR of 50% (where sex-roles switch). This approach enabled a comparison with a previous model. We found that the OSR was influenced by the distribution of matings in time and among males when the male mating phase was limited by a parental phase. Furthermore, the mating dynamics were shaped by the fact that the numbers of males and females and their capacities for collateral investment affected OSR immediately from the start of the reproductive season, whereas their times-out had a delayed effect on OSR. (c) 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 89, 551-559.
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38.
  • Kvarnemo, Charlotta, 1963, et al. (författare)
  • Molecular, behavioural and morphological comparisons of sperm adaptations in a fish with alternative reproductive tactics
  • 2023
  • Ingår i: Evolutionary Applications. - : Wiley. - 1752-4571. ; 16:2, s. 338-53
  • Tidskriftsartikel (refereegranskat)abstract
    • In species with alternative reproductive tactics, there is much empirical support that parasitically spawning males have larger testes and greater sperm numbers as an evolved response to a higher degree of sperm competition, but support for higher sperm performance (motility, longevity and speed) by such males is inconsistent. We used the sand goby (Pomatoschistus minutus) to test whether sperm performance differed between breeding-coloured males (small testes, large mucus-filled sperm-duct glands; build nests lined with sperm-containing mucus, provide care) and parasitic sneaker-morph males (no breeding colouration, large testes, rudimentary sperm-duct glands; no nest, no care). We compared motility (per cent motile sperm), velocity, longevity of sperm, gene expression of testes and sperm morphometrics between the two morphs. We also tested if sperm-duct gland contents affected sperm performance. We found a clear difference in gene expression of testes between the male morphs with 109 transcripts differentially expressed between the morphs. Notably, several mucin genes were upregulated in breeding-coloured males and two ATP-related genes were upregulated in sneaker-morph males. There was a partial evidence of higher sperm velocity in sneaker-morph males, but no difference in sperm motility. Presence of sperm-duct gland contents significantly increased sperm velocity, and nonsignificantly tended to increase sperm motility, but equally so for the two morphs. The sand goby has remarkably long-lived sperm, with only small or no decline in motility and velocity over time (5 min vs. 22 h), but again, this was equally true for both morphs. Sperm length (head, flagella, total and flagella-to-head ratio) did not differ between morphs and did not correlate with sperm velocity for either morph. Thus, other than a clear difference in testes gene expression, we found only modest differences between the two male morphs, confirming previous findings that increased sperm performance as an adaptation to sperm competition is not a primary target of evolution.
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39.
  • Kvarnemo, Charlotta, 1963 (författare)
  • Parental care
  • 2010
  • Ingår i: Evolutionary Behavioral Ecology / edited by David F. Westneat, Charles W. Fox.. - New York : Oxford University Press. - 9780195331936
  • Bokkapitel (övrigt vetenskapligt/konstnärligt)
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40.
  • Kvarnemo, Charlotta, 1963, et al. (författare)
  • Polyandry as a mediator of sexual selection before and after mating
  • 2013
  • Ingår i: Philosophical Transactions of the Royal Society B-Biological Sciences. - : The Royal Society. - 0962-8436 .- 1471-2970. ; 368:1613
  • Tidskriftsartikel (refereegranskat)abstract
    • The Darwin–Bateman paradigm recognizes competition among males for access to multiple mates as the main driver of sexual selection. Increasingly, however, females are also being found to benefit from multiple mating so that polyandry can generate competition among females for access to multiple males, and impose sexual selection on female traits that influence their mating success. Polyandry can reduce a male's ability to monopolize females, and thus weaken male focused sexual selection. Perhaps the most important effect of polyandry on males arises because of sperm competition and cryptic female choice. Polyandry favours increased male ejaculate expenditure that can affect sexual selection on males by reducing their potential reproductive rate. Moreover, sexual selection after mating can ameliorate or exaggerate sexual selection before mating. Currently, estimates of sexual selection intensity rely heavily on measures of male mating success, but polyandry now raises serious questions over the validity of such approaches. Future work must take into account both pre- and post-copulatory episodes of selection. A change in focus from the products of sexual selection expected in males, to less obvious traits in females, such as sensory perception, is likely to reveal a greater role of sexual selection in female evolution.
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41.
  • Kvarnemo, Charlotta, 1963 (författare)
  • Sex hos djur
  • 2009
  • Ingår i: Djuren och människan - Om den moderna biologin och dess världsbild. - Lund : Studentlitteratur. - 9789144048888 ; , s. 177-194
  • Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
    • Sex kan betyda flera saker, såsom kön, sexualitet och fortplantningsbeteende. Detta kapitel tar upp sex hos djur i alla dessa betydelser. Kapitlet handlar främst om variationsrikedomen i djurs fortplantningsbeteenden, men även om naturen som förebild och huruvida naturen är "god".
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42.
  • Kvarnemo, Charlotta, 1963, et al. (författare)
  • Sexually selected females in the monogamous Western Australian seahorse.
  • 2007
  • Ingår i: Proceedings. Biological sciences / The Royal Society. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 274:1609, s. 521-5
  • Tidskriftsartikel (refereegranskat)abstract
    • Studies of sexual selection in monogamous species have hitherto focused on sexual selection among males. Here, we provide empirical documentation that sexual selection can also act strongly on females in a natural population with a monogamous mating system. In our field-based genetic study of the monogamous Western Australian seahorse, Hippocampus subelongatus, sexual selection differentials and gradients show that females are under stronger sexual selection than males: mated females are larger than unmated ones, whereas mated and unmated males do not differ in size. In addition, the opportunity for sexual selection (variance in mating success divided by its mean squared) for females is almost three times that for males. These results, which seem to be generated by a combination of a male preference for larger females and a female-biased adult sex ratio, indicate that substantial sexual selection on females is a potentially important but under-appreciated evolutionary phenomenon in monogamous species.
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43.
  • Kvarnemo, Charlotta, 1963 (författare)
  • Stressed singers and symmetric lovers
  • 2011
  • Ingår i: Behavioral Ecology. ; 22, s. 11-12
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
  •  
44.
  • Kvarnemo, Charlotta, 1963, et al. (författare)
  • Testes investment and spawning mode in pipefishes and seahorses (Syngnathidae).
  • 2004
  • Ingår i: Biological Journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4066 .- 1095-8312. ; 83:3, s. 369-376
  • Tidskriftsartikel (refereegranskat)abstract
    • Externally fertilizing fishes are predicted to invest heavily in testes, because large numbers of sperm should be favoured by the high risk of sperm competition from sneaker males, and/or the dilution of ejaculates when shed into open water. Using museum specimens, we measured testes mass and body mass of 83 mature males, belonging to 21 genera of the family Syngnathidae (pipefishes and seahorses). In this family all species show paternal care, ranging in degree from eggs being attached to the skin of the male, to eggs being completely enclosed and nurtured within a brood pouch. The former, 'unprotected' group, is thought to have external fertilization, whereas in the latter, 'protected' group, males fertilize the eggs internally in their brood pouch. Smaller relative testes investment was thus predicted for genera that have protected compared with unprotected brood care. However, we found this not to be the case. Instead, all genera showed the same relationship between testes and body mass, regardless of brooding type. The possible implications of this surprising result are discussed, including the possibility that the mode of fertilization might have been misjudged for the pouchless syngnathids. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society, 2004, 83, 369–376.
  •  
45.
  • Kvarnemo, Charlotta, 1963 (författare)
  • Why do some animals mate with one partner rather than many? A review of causes and consequences of monogamy.
  • 2018
  • Ingår i: Biological Reviews of the Cambridge Philosophical Society. - : Wiley. - 1469-185X. ; 93, s. 1795-1812
  • Forskningsöversikt (refereegranskat)abstract
    • Why do some animals mate with one partner rather than many? Here, I investigate factors related to (i) spatial constraints (habitat limitation, mate availability), (ii) time constraints (breeding synchrony, length of breeding season), (iii) need for parental care, and (iv) genetic compatibility, to see what support can be found in different taxa regarding the importance of these factors in explaining the occurrence of monogamy, whether shown by one sex (monogyny or monandry) or by both sexes (mutual monogamy). Focusing on reproductive rather than social monogamy whenever possible, I review the empirical literature for birds, mammals and fishes, with occasional examples from other taxa. Each of these factors can explain mating patterns in some taxa, but not in all. In general, there is mixed support for how well the factors listed above predict monogamy. The factor that shows greatest support across taxa is habitat limitation. By contrast, while a need for parental care might explain monogamy in freshwater fishes and birds, there is clear evidence that this is not the case in marine fishes and mammals. Hence, reproductive monogamy does not appear to have a single overriding explanation, but is more taxon specific. Genetic compatibility is a promising avenue for future work likely to improve our understanding of monogamy and other mating patterns. I also discuss eight important consequences of reproductive monogamy: (i) parentage, (ii) parental care, (iii) eusociality and altruism, (iv) infanticide, (v) effective population size, (vi) mate choice before mating, (vii) sexual selection, and (viii) sexual conflict. Of these, eusociality and infanticide have been subject to debate, briefly summarised herein. A common expectation is that monogamy leads to little sexual conflict and no or little sexual selection. However, as reviewed here, sexual selection can be substantial under mutual monogamy, and both sexes can be subject to such selection. Under long-term mutual monogamy, mate quality is obviously more important than mate numbers, which in turn affects the need for pre-mating mate choice. Overall, I conclude that, despite much research on genetic mating patterns, reproductive monogamy is still surprisingly poorly understood and further experimental and comparative work is needed. This review identifies several areas in need of more data and also proposes new hypotheses to test.
  •  
46.
  • Leder, Erica H, 1967, et al. (författare)
  • Post-glacial establishment of locally adapted fish populations over a steep salinity gradient
  • 2021
  • Ingår i: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 34:1, s. 138-56
  • Tidskriftsartikel (refereegranskat)abstract
    • Studies of colonization of new habitats that appear from rapidly changing environments are interesting and highly relevant to our understanding of divergence and speciation. Here, we analyse phenotypic and genetic variation involved in the successful establishment of a marine fish (sand goby,Pomatoschistus minutus) over a steep salinity drop from 35 PSU in the North Sea (NE Atlantic) to two PSU in the inner parts of the post-glacial Baltic Sea. We first show that populations are adapted to local salinity in a key reproductive trait, the proportion of motile sperm. Thereafter, we show that genome variation at 22,190 single nucleotide polymorphisms (SNPs) shows strong differentiation among populations along the gradient. Sequences containing outlier SNPs and transcriptome sequences, mapped to a draft genome, reveal associations with genes with relevant functions for adaptation in this environment but without overall evidence of functional enrichment. The many contigs involved suggest polygenic differentiation. We trace the origin of this differentiation using demographic modelling and find the most likely scenario is that at least part of the genetic differentiation is older than the Baltic Sea and is a result of isolation of two lineages prior to the current contact over the North Sea-Baltic Sea transition zone.
  •  
47.
  • Lehtonen, Topi K., et al. (författare)
  • Density effects on fish egg survival and infections depend on salinity
  • 2015
  • Ingår i: Marine Ecology Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 540, s. 183-191
  • Tidskriftsartikel (refereegranskat)abstract
    • Across taxa, egg survival is a critical component of reproductive success. Eggs in aquatic environments can be strongly influenced by both extrinsic and intrinsic factors, of which egg density in particular has been subjected to a limited body of research. In this study, we experimentally manipulated both egg density and water salinity—a key environmental condition— and assessed egg infection rate and survival in a small marine fish with paternal egg care, the sand goby Pomatoschistus minutus. We controlled for the potential confounding effect of parental care by rearing the eggs artificially. We found that both high salinity and reduced egg density treatments were associated with a higher proportion of eggs surviving to the eye-spot stage. Furthermore, the positive survival effect of reduced density was more pronounced (in relative terms) in low salinity. In contrast, a reduced egg density was actually negatively associated with the proportion of healthy-looking, uninfected eggs in high (but not low) salinity. The first signs of infection, in turn, appeared quicker under low salinity, independent of density. Together, these results demonstrate context-dependent effects of density on egg performance, and identify a potentially significant role for parental care (especially filial cannibalism) in suppressing the spread of egg infections. Furthermore, the benefits of a low egg density are not only related to infections, but they can also vary depending on the physical environment. Overall, the results highlight the role of egg performance in the face of changing environmental conditions.
  •  
48.
  • Lehtonen, Topi K., et al. (författare)
  • Effects of salinity on nest-building behaviour in a marine fish
  • 2016
  • Ingår i: BMC Ecology. - : Springer Science and Business Media LLC. - 1472-6785. ; 16
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Parental allocation and reproductive success are often strongly influenced by environmental factors. In this respect, salinity is a key factor influencing species distributions and community structure in aquatic animals. Nevertheless, the effects of salinity on reproductive behaviours are not well known. Here, we used the sand goby (Pomatoschistus minutus), a small fish inhabiting a range of different salinities, to experimentally assess the effects of changes in salinity on nesting behaviour, a key component of reproduction in sand gobies and many other taxa. Results: We found that salinity levels influenced some aspects of male nesting behaviour (i.e. nest entrance size) but not others (i.e. latency to build a nest, choice of nest site, sand on top of nest) and that small and large individuals were differently affected. In particular, the importance of body size in adjustment of nest entrance depended on the salinity level. Conclusion: The results support the prediction that geographically widespread aquatic species, such as sand gobies, are able to perform well under a range of salinity levels. The phenotype by environment interaction found between male size and behavioural responses to salinity can, in turn, help to explain the notable variation observed in nest-building (and other) behaviours closely linked to reproduction.
  •  
49.
  • Lehtonen, T. K., et al. (författare)
  • Infections may select for filial cannibalism by impacting egg survival in interaction with water salinity and egg density.
  • 2015
  • Ingår i: Oecologia. - : Springer Science and Business Media LLC. - 0029-8549 .- 1432-1939. ; 178:3, s. 673-683
  • Tidskriftsartikel (refereegranskat)abstract
    • In aquatic environments, externally developing eggs are in constant contact with the surrounding water, highlighting the significance of water parameters and pathogens for egg survival. In this study we tested the impact of water salinity, egg density and infection potential of the environment on egg viability in the sand goby (Pomatoschistus minutus), a small fish that exhibits paternal egg care and has a marine origin, but which in the Baltic Sea lives in brackish water. To manipulate the infection potential of the environment, we added either a Saprolegnia infection vector into UV-filtered water or a fungicide into natural Baltic Sea water. Saprolegnia are widely spread water moulds that are a key cause of egg mortality in aquatic organisms in fresh- and brackish water. We found that increased water salinity indeed decreased the egg infection rate and had a positive effect on egg viability, while high egg density tended to have the opposite effect. However, the different factors influenced egg viability interactively, with a higher egg density having negative effects at low, but not in high, salinity. Thus, the challenges facing marine organisms adapting to lower salinity levels can be amplified by Saprolegnia infections that reduce egg survival in interaction with other environmental factors. Our results support the hypothesis that suppressing egg infections is an important aspect of parental care that can select for filial cannibalism, a common but poorly understood behaviour, especially in fish with parental care.
  •  
50.
  • Lehtonen, T. K., et al. (författare)
  • Odour cues from suitors' nests determine mating success in a fish
  • 2015
  • Ingår i: Biology Letters. - : The Royal Society. - 1744-9561 .- 1744-957X. ; 11:5
  • Tidskriftsartikel (refereegranskat)abstract
    • Animals use a range of sensory cues for finding food, avoiding predators and choosing mates. In this regard, the aquatic environment is particularly suitable for the use of olfactory and other chemical cues. Nevertheless, mate choice research, even on aquatic organisms, has focused on visual signals, while chemical cues relevant in sexual selection have been assumed to be 'intrinsic' excretions of mate candidates. Here, using the sand goby Pomatoschistus minutus, a small fish with paternal egg care, we investigated the possibility that 'extrinsic' chemical cues in the males' nests could also have a significant contribution to mating success. We found that females strongly avoided laying eggs into nests subject to the odour of Saprolegnia water moulds (an egg infection) and that this effect was independent of the females' initial, visually based preference for males. To the best of our knowledge, this is the first study to show that chemical cues related to parental failure can play a large role in sexual selection.
  •  
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