| 1. |
- Lindsay, Willow, 1980, et al.
(författare)
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Endless forms of sexual selection
- 2019
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Ingår i: PeerJ. - : PeerJ. - 2167-8359. ; 7
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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. |
- Lindström, Kai, et al.
(författare)
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Sperm adaptation in relation to salinity in three goby species
- 2021
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Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649.
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Tidskriftsartikel (refereegranskat)abstract
- In externally fertilizing species, the gametes of both males and females are exposed to the influences of the environment into which they are released. Sperm are sensitive to abiotic factors such as salinity, but they are also affected by biotic factors such as sperm competition. In this study, the authors compared the performance of sperm of three goby species, the painted goby, Pomatoschistus pictus, the two-spotted goby, Pomatoschistus flavescens, and the sand goby, Pomatoschistus minutus. These species differ in their distributions, with painted goby having the narrowest salinity range and sand goby the widest. Moreover, data from paternity show that the two-spotted goby experiences the least sperm competition, whereas in the sand goby sperm competition is ubiquitous. The authors took sperm samples from dissected males and exposed them to high salinity water (31 PSU) representing the North Sea and low salinity water (6 PSU) representing the brackish Baltic Sea Proper. They then used computer-assisted sperm analysis to measure the proportion of motile sperm and sperm swimming speed 10 min and 20 h after sperm activation. The authors found that sperm performance depended on salinity, but there seemed to be no relationship to the species' geographical distribution in relation to salinity range. The species differed in the proportion of motile sperm, but there was no significant decrease in sperm motility during 20 h. The sand goby was the only species with motile sperm after 72 h.
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| 3. |
- Svensson, Ola, 1971, et al.
(författare)
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How sexual and natural selection interact and shape the evolution of nests and nesting behaviour in fishes
- 2023
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Ingår i: Philosophical Transactions of the Royal Society of London. Biological Sciences. - 0962-8436 .- 1471-2970. ; 378:1884
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Forskningsöversikt (refereegranskat)abstract
- Among ray-finned fishes that provide parental care, many spawn in constructed nests, ranging from bowls, burrows and ridges to nests made of algae or bubbles. Because a nest by definition is a construction that enhances the nest-builder's fitness by helping it meet the needs of the developing offspring, nest-building behaviour is naturally selected, as is a preference for spawning with mates that provide well-built nests. However, nest-building behaviour can also be sexually selected, when nest traits increase mating success, protect against sperm competition or nest take-overs by conspecifics. Here, we offer a systematic review, with examples of how competition for sites and location of fish nests relates to sexual selection. We examine direct and indirect benefits of mate choice linked to nest traits, and different types of nests, from a sexual selection perspective. Nest-related behaviours are often under both natural and sexual selection, and we disentangle examples where that is the case, with special attention to females. We highlight some taxa in which nest building is likely to be sexually selected, but lack of research has left them uninvestigated. Some of them are established aquarium species, making them particularly amenable for future research. Finally, we compare with arthropods, amphibians and birds.
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| 4. |
- Svensson, Ola, 1971-, et al.
(författare)
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Data from: Sympatry and parapatry among rocky reef cichlids of Lake Victoria explained by female mating preferences [Dataset]
- 2024
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Annan publikationabstract
- Work on the Lake Victoria cichlids Pundamilia nyererei (red dorsum males, deeper water), Pundamilia pundamilia (blue males, shallower water) and related species pairs has provided insights into processes of speciation. Here, we investigate female mating behaviour of five Pundamilia species and four of their F1-hybrids through mate choice trials and paternity testing. We discuss the results in the context of the geography of speciation and coexistence. Complete assortative mating was observed among all sympatric species. Parapatric species with similar depth habitat distributions interbred whereas other parapatric and allopatric species showed complete assortative mating. F1-hybrids mated exclusively with species accepted by females of the parental species. Although consistent with reinforcement in sympatry, a closer look at our results suggests otherwise and it is more likely that pre-existing female preferences influence which taxa can co-exist in sympatry. Regardless of the mechanism, mating preferences may influence species distribution in potentially hybridizing taxa, such as in the adaptive radiations of cichlid fish. We suggest that this at least partly explains why some species fail to establish breeding populations in locations where they are occasionally recorded. Our result support the notion that mating preferences of potentially cross-breeding species ought to be included in coexistence theory.
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| 5. |
- Svensson, Ola, 1971-, et al.
(författare)
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Supporting information about Pundamilia azurea, Pundamilia igneopinnis, Pundamilia nyererei, Pundamilia pundamilia and Pundamilia sp. ‘red head’ : Supplementary Material S1
- 2023
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Annan publikation (refereegranskat)abstract
- Among all known Lake Victoria haplochromines, females alone brood the eggs and fry in their mouths, occasional exceptions in the lab notwithstanding (Seehausen 1996). Free-swimming fry are guarded for a few days (Seehausen, 1996). Long-term pair bonds are unknown, and the offspring of a single clutch may be sired by multiple males (Svensson et al., 2017). Females are generally more cryptic, whereas males are larger, more conspicuous and aggressively territorial (Seehausen, 1996). The males have bright nuptial colouration of either one of three patterns that are widespread among Lake Victoria cichlid species and referred to as ‘blue’, ‘red dorsum’ or ‘red chest’ (Seehausen et al., 1998; Seehausen and van Alphen, 1999), each of which also exists in melanic forms where the underlying colour pattern can be largely disguised. Among rocky shore cichlids, these different colour pattern groups are associated with different habitats: ‘blue’ and ‘red chest’ males breed in shallow water over gently sloping substrate, ‘red dorsum’ males breed in similar habitats but deeper, and melanic forms breed even deeper or at steeply dropping rock faces (Seehausen, 1996). The five species of the present study belong to a complex of more than 20 congeneric taxa (Seehausen, 1996; Seehausen et al., 1998). They originate from south-eastern Lake Victoria (Tanzania) around islands in the Speke Gulf; Igombe Island, Makobe Island, Ruti Island, Zue Island, not further apart than 50km (Figure 1). All have similar ecology, inhabiting rocky shores and reefs and feeding largely on plankton and benthic invertebrates (Bouton et al., 1997; Maan et al., 2008; Seehausen, 1996; Seehausen et al., 1998). Their phylogenetic relationships are complicated and characterized by lineage fusion through admixture and lineage fission through speciation (Meier et al., in press).
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| 6. |
- Svensson, Ola, 1971-, et al.
(författare)
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Sympatry and parapatry among rocky reef cichlids of Lake Victoria explained by female mating preferences
- 2023
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Ingår i: Journal of Evolutionary Biology. - 1010-061X .- 1420-9101.
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Tidskriftsartikel (refereegranskat)abstract
- Work on the Lake Victoria cichlids Pundamilia nyererei (red dorsum males, deeper water), Pundamilia pundamilia (blue males, shallower water) and related species pairs has provided insights into processes of speciation. Here, we investigate the female mating behaviour of 5 Pundamilia species and 4 of their F1 hybrids through mate choice trials and paternity testing. Complete assortative mating was observed among all sympatric species. Parapatric species with similar depth habitat distributions interbred whereas other parapatric and allopatric species showed complete assortative mating. F1 hybrids mated exclusively with species accepted by females of the parental species. The existence of complete assortative mating among some currently allopatric species suggests that pre-existing mating barriers could be sufficient to explain current patterns of co-existence, although, of course, many other factors may be involved. Regardless of the mechanism, mating preferences may influence species distribution in potentially hybridizing taxa, such as in the adaptive radiation of cichlid fish. We suggest that this at least partly explains why some species fail to establish breeding populations in locations where they are occasionally recorded. Our results support the notion that the mating preferences of potentially cross-breeding species ought to be included in coexistence theory.
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| 7. |
- Asnicar, Davide, et al.
(författare)
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Sand Goby : An Ecologically Relevant Species for Behavioural Ecotoxicology
- 2018
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Ingår i: Fishes. - : MDPI. - 2410-3888. ; 3:1
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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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| 8. |
- Blom, Eva-Lotta, 1973, et al.
(författare)
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Male acoustic display in the sand goby – Essential cue in female choice, but unaffected by supplemental feeding
- 2022
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Ingår i: Journal of Experimental Marine Biology and Ecology. - : Elsevier. - 0022-0981 .- 1879-1697. ; 556
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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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| 9. |
- Andersson, Marica, et al.
(författare)
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Increased noise levels cause behavioural and distributional changes in Atlantic cod and saithe in a large public aquarium—A case study
- 2023
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Ingår i: Aquaculture, Fish and Fisheries. - : John Wiley & Sons. - 2693-8847.
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Investigating the effects of underwater noise on aquatic animals is a research field that is receiving rapidly increasing attention. Despite this, surprisingly few studies have addressed the potential impacts of noise in a marine animal husbandry setting. In this regard, the behaviour of fish in public aquariums can be used as an indicator of well-being, and noise is known to cause behavioural changes. This case study investigates the behaviour of cod (Gadus morhua) and saithe (Pollachius virens) in a large public aquarium when exposed to increased noise levels originating from an aquarium renovation carried out by construction divers. Swimming behaviour, group formation and vertical distribution, along with yawning and scratching frequencies of the fish, were analysed from video recordings made before, during and after the exposure to increased noise levels. The same parameters were also analysed to evaluate potential effects of the presence of divers when not making renovation noise, compared to fish behaviour prior to the renovation. There was a slight change in the depth distribution of both species and a decrease in the number of scratches in cod due to the presence of divers that were not making renovation noise. In the presence of construction noises in the tank, however, both cod and saithe showed a wider array of behavioural changes, including increased swimming speed, changes in depth distribution and increased yawning frequencies. The results from this case study demonstrate that an underwater renovation with increased noise levels impacts fish behaviour and suggests that underwater noise should be considered during the management of aquatic environments, including public aquaria.
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| 10. |
- Pedroso, S. S., et al.
(författare)
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Courtship Sounds Advertise Species Identity and Male Quality in Sympatric Pomatoschistus spp. Gobies
- 2013
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 8:6
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Tidskriftsartikel (refereegranskat)abstract
- Acoustic signals can encode crucial information about species identity and individual quality. We recorded and compared male courtship drum sounds of the sand goby Pomatoschistus minutus and the painted goby P. pictus and examined if they can function in species recognition within sympatric populations. We also examined which acoustic features are related to male quality and the factors that affect female courtship in the sand goby, to determine whether vocalisations potentially play a role in mate assessment. Drums produced by the painted goby showed significantly higher dominant frequencies, higher sound pulse repetition rates and longer intervals between sounds than those of the sand goby. In the sand goby, male quality was predicted by visual and acoustic courtship signals. Regression analyses showed that sound amplitude was a good predictor of male length, whereas the duration of nest behaviour and active calling rate (i.e. excluding silent periods) were good predictors of male condition factor and fat reserves respectively. In addition, the level of female courtship was predicted by male nest behaviour. The results suggest that the frequency and temporal patterns of sounds can encode species identity, whereas sound amplitude and calling activity reflects male size and fat reserves. Visual courtship duration (nest-related behaviour) also seems relevant to mate choice, since it reflects male condition and is related to female courtship. Our work suggests that acoustic communication can contribute to mate choice in the sand goby group, and invites further study.
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