| 1. |
- Aronsen, T., et al.
(författare)
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The operational sex ratio and density influence spatial relationships between breeding pipefish
- 2013
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Ingår i: Behavioral Ecology. - : Oxford University Press (OUP). - 1045-2249 .- 1465-7279. ; 24:4, s. 888-897
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Tidskriftsartikel (refereegranskat)abstract
- The operational sex ratio (ratio of sexually receptive males to females) has been extensively studied in behavioral ecology, whereas other demographic factors such as the effect of density on mating behavior have received less empirical attention. We manipulated mating competition by establishing breeding populations of the sex-role reversed broad-nosed pipefish (Syngnathus typhle) at 2 sex ratios (male biased or female biased) and 2 densities. We used mean crowding (m*) and the index of association (X) to measure spatial distributions within and between the sexes, respectively, and investigated how these measures reflect the predicted strength of mating competition. In general, female m* increased as fewer males were available for mating, which suggests increased intrasexual competition in the most competitive sex. However, male m* also increased as the operational sex ratio became more female biased, suggesting that m* did not reflect mating competition for males. Association between the sexes (X) was higher under male bias than female bias, probably because males were still available for mating under male bias. In addition, X decreased in the female-biased treatment as the operational sex ratio became even more female biased. Higher density increased m* in both sex ratios and sexes, although for both sexes in the female-biased high-density treatment the operational sex ratio did not influence m*, probably because femalefemale competition inhibits further crowding in this treatment. In this study, we show that the use of m* and X can be a useful tool in behavioral studies but their interpretation requires detailed information about the mating system. Therefore, we recommend caution with their broadscale application.
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| 2. |
- Brüde Sundin, Josefin
(författare)
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Rektorn - ingen nobody
- 2014
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Ingår i: Dynamiska och komplexa miljöer. - Linköping : Linköpings universitet, Institutionen för beteendevetenskap och lärande. - 9789175192031 ; , s. 21-31
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 3. |
- Landis, Susanne H., et al.
(författare)
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Behavioral adjustments of a pipefish to bacterial Vibrio challenge
- 2012
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Ingår i: Behavioral Ecology and Sociobiology. - : Springer Science and Business Media LLC. - 0340-5443 .- 1432-0762. ; 66:10, s. 1399-1405
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Tidskriftsartikel (refereegranskat)abstract
- Animals can profit from increasing temperatures by prolonged breeding seasons and faster growth rates. However, these fitness benefits are traded off against higher parasite load and increased virulence of temperature-sensitive pathogens. In thermally stratified habitats, behavioral plasticity can allow hosts to choose the optimal temperature to enhance individual fitness and to escape parasite pressure. To test this idea, we performed a temperature choice experiment with the host-parasite system of the sex-role reversed broad-nosed pipefish (Syngnathus typhle) and its bacterial pathogen Vibrio spp. In this species, pregnant males are expected to face a trade-off between shortening their brooding period in warm water and decreasing the effect of the infection in cold water. We found that exposure to Vibrio changed the temperature preference for both pregnant and nonpregnant males, as well as females compared to nonchallenged fish that tended to prefer warm water. This study shows that behavioral plasticity is one option for avoidance of higher bacterial prevalence, as expected due to rising ocean temperatures.
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| 4. |
- Lindqvist, Charlotte, et al.
(författare)
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Male broad-nosed pipefish Syngnathus typhle do not locate females by smell
- 2011
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Ingår i: Journal of Fish Biology. - London : Academic Press. - 0022-1112 .- 1095-8649. ; 78:6, s. 1861-1867
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Tidskriftsartikel (refereegranskat)abstract
- Broad-nosed pipefish Syngnathus typhle were used to investigate whether males used scent in their search for mates. When the males in an experiment had access to olfactory cues only, they did not locate females better than they located males. Thus, S. typhle, was less successful in mate search when visual cues were absent.
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| 5. |
- Ljunggren, Nils, et al.
(författare)
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Eliminering av signalkräfta på Gotland : En redovisning av utförda åtgärder inom åtgärdsprogrammet för bevarande av flodkräfta under 2007-2009
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- SummaryThe Noble crayfish,Astacus astacus (also called the European crayfish or the broad-fingeredcrayfish) used to be the most common crayfish species in Sweden and Europe. It issusceptible to the crayfish plague,Aphanomyces astaci, and since 1907, when the firstoutbreak of crayfish plague was noted in Sweden, the Swedish Noble crayfish population hasdecreased with 97 %. The pattern is the same in all of Europe. To compensate for thediminishing Noble crayfish populations, Signal crayfish, Pacifastacus leniusculus wasintroduced into Europe (in Sweden in 1960). However, despite its resistance to crayfishplague, it still acts as a carrier of the disease. Thus, the introduction of the Signal crayfish mayhave accelerated the extinction rate of native crayfish populations. In Europe, the IUCN RedList of Threatened Species classifies the Noble crayfish as vulnerable. In Sweden theprospects for the crayfish are even worse, and the Official Swedish Red List classifies theNoble crayfish as Critical Endangered (based on the IUCN Red List criteria), facing anextremely high risk of extinction in the wild in the immediate future.The Swedish island of Gotland, situated in the Baltic Sea, is the first protected area in Swedenfor the Noble crayfish. No known outbreaks of crayfish plague have been confirmed onGotland, and Gotland is considered one of the very few areas left in Sweden that are notexposed to the crayfish plague. However, on Gotland there are three confirmed water bodieswhere Signal crayfish has been illegally introduced. The County Administrative Board onGotland was given the formal commission to exterminate any occurring populations of theSignal crayfish, as they can be carriers of the crayfish plague. This report contains of theactions taken to eliminate the Signal crayfish populations on Gotland during the years 2007–2009.The three localities where Signal crayfish occurs, including the ponds and the surroundingenvironment, was firmly investigated concerning the physical property and the composition ofthe ecosystem. The ponds where then treated with a pesticide containing the active substancedeltamethrin, with the aim of extinguishing all Signal crayfish. Deltamethrin is a syntheticpyrethroid insecticide, widely used on crops, as it is stable, less volatile and environmentallycompatible. The toxicity on mammals, including humans, and bird is relatively low ascompared to other pesticides, while it has been shown to be lethal to arthropods in very lowconcentrations. The ponds were treated with a dose aimed to reach a concentration of 0.5 μgdeltamethrin/l to obtain lethal doses.The outcome of the extermination of the signal crayfish in the three localities on Gotland wassuccessful so far. No live crayfish was found after the treatment, and all crayfish that wereplaced in cages in the ponds to control for the effectiveness of the pesticide treatment died.The concentration of deltamethrin declined rapidly and reached values below 0.1 μg/l, theEuropean Union drinking water limit, within one or a couple of weeks. The final succes ofthese actions is still uncertain as surviving individuals may take several years to detect.Inspections at all sites during the following years need to be carried out in order to determineif the Signal crayfish was completely exterminated from Gotland.
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| 6. |
- Roth, O., et al.
(författare)
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Male mate choice relies on major histocompatibility complex class I in a sex-role-reversed pipefish
- 2014
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Ingår i: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 27:5, s. 929-938
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Tidskriftsartikel (refereegranskat)abstract
- Mate choice for compatible genes is often based on genes of the major histocompatibility complex (MHC). Although MHC-based mate choice is commonly observed in female choice, male mate choice remains elusive. In particular, if males have intense paternal care and are thus the choosing sex, male choice for females with dissimilar MHC can be expected. Here, we investigated whether male mate choice relies on MHC class I genes in the sex-role reversed pipefish Syngnathus typhle. In a mate choice experiment, we determined the relative importance of visual and olfactory cues by manipulating visibility and olfaction. We found that pipefish males chose females that maximize sequence-based amino acid distance between MHC class I genotypes in the offspring when olfactory cues were present. Under visual cues, large females were chosen, but in the absence of visual cues, the choice pattern was reversed. The use of sex-role reversed species thus revealed that sexual selection can lead to the evolution of male mate choice for MHC class I genes.
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| 7. |
- Sundin, Josefin, et al.
(författare)
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Altered oceanic pH impairs mating propensity in a pipefish
- 2013
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Ingår i: Ethology. - : Wiley. - 0179-1613 .- 1439-0310. ; 119:1, s. 86-93
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Tidskriftsartikel (refereegranskat)abstract
- Anthropogenic disturbance is currently altering the environment of terrestrial as well as aquatic organisms. Those changes affect a variety of animal behaviours, which in turn may cause changes in species interactions, population dynamics and evolutionary processes. In marine ecosystems, nutrient enrichment may elevate pH, while it is reduced by carbon dioxide-induced ocean acidification. These two processes are not expected to balance one another but rather to affect the environment at different times and scales. We here show experimentally that an increase in water pH has a negative effect on mating propensity in the broad-nosed pipefish Syngnathus typhle, whereas lowered pH did not elicit the same detrimental effect. This study provides, to our knowledge, the first evidence that mating propensity is impaired by an increase in pH, suggesting that anthropogenic nutrient enrichment in aquatic ecosystems may change the processes of sexual selection and population dynamics solely on the basis of altered water pH.
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| 8. |
- Sundin, Josefin, et al.
(författare)
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Female mate choice is not affected by mate condition in a fish with male care
- 2013
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Ingår i: Acta Ethologica. - : Springer Science and Business Media LLC. - 0873-9749 .- 1437-9546. ; 16:3, s. 189-194
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Tidskriftsartikel (refereegranskat)abstract
- Several studies have shown that mate choice based on condition leads to higher reproductive success of the choosing individual. Yet, a growing body of literature has failed to find support for mate choice based on mate condition, even when the choosing individual would clearly benefit from such a choice. This indicates that animals' mate choice is often more complex than currently appreciated and that even well-founded expected preferences cannot be taken for granted. Using the broad-nosed pipefish, Syngnathus typhle, we manipulated male condition experimentally to explore whether it affects female mate choice. In this sex-role-reversed species, males care for the offspring in a specialised brood pouch. Males are the choosier sex, but given the opportunity, females are selective as well. During brooding, males can both provide embryos with nutrients and take up nutrients that originate from eggs deposited in the pouch, and embryo survival correlates positively with male condition. Together, this suggests that it would be beneficial for females to mate with males in high condition. However, we found no female preference for males in better condition. Thus, this study adds to the literature of mate choice that is unaffected by mate condition. Possible reasons for our result are discussed.
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| 9. |
- Sundin, Josefin, 1981-
(författare)
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Sex in Murky Waters : Anthropogenic Disturbance of Sexual Selection in Pipefish
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Animals experience variation in their environment because of natural changes. However, due to anthropogenic disturbance, the speed and severity of these changes have recently increased. This thesis investigates how reproductive behaviours may be affected by human induced environmental change. In specific, I investigate how visual and chemical changes in the aquatic environment, caused by eutrophication, affect mating systems and sexual selection in fish. Broad-nosed- and straight-nosed pipefish, which both have been studied in detail for a long period, were used as model organisms. These two species are particularly suitable model organisms since they perform complex courtship behaviours, including the advertisement of ornaments and a nuptial dance. Further, two distinct populations were studied, one on the Swedish west coast and one in the Baltic Sea, as these two locations vary in the degree and extent of environmental disturbance, in particular turbidity. I found that changes in the visual environment had no impact on the development of female sexual ornaments in these sex-role reversed pipefishes, but it hampered adaptive mate choice. Turbidity also had a negative effect on reproductive success in the Baltic Sea population. Changes in the chemical environment in the form of increased pH reduced the probability to mate, while hypoxia did not alter mating propensity. However, hypoxic water delayed the onset of both courting and mating. Hence, human induced change in aquatic environments may alter the processes of sexual selection and population dynamics.
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| 10. |
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