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Jacqueline D. Litzgus - One of the best experts on this subject based on the ideXlab platform.
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Sex, shells, and weaponry: coercive Reproductive Tactics in the painted turtle, Chrysemys picta
Behavioral Ecology and Sociobiology, 2020Co-Authors: Patrick D. Moldowan, Ronald J. Brooks, Jacqueline D. LitzgusAbstract:Males and females have divergent Reproductive interests arising from their unequal investments in offspring. This sexual conflict drives an antagonistic arms race that influences sex-specific Reproductive success. Alternative Reproductive Tactics are expected in long-lived species for which the Reproductive strategy that maximizes mating success could differ across body sizes. The mating strategy of the painted turtle ( Chrysemys picta ) has been characterized as an elaborate and amiable male courtship display during which males use their elongate foreclaws to stroke females, coupled with female mate choice. Contrary to this long-held understanding, in situ field observations and experimental trials from our long-term study in Algonquin Provincial Park, Canada, demonstrate that males also exhibit an alternative, coercive mating strategy. Males are equipped with sexually size dimorphic tomiodonts, tooth-like cusps of the beak, as well as a weaponized anterior shell, with which they wound the head and neck of females. Behavioral trials during the breeding periods showed that male Reproductive Tactics shift from courtship (foreclaw display) to coercion (striking, biting, and forced submergence) across ontogeny, and male size predicts the occurrence and frequency of coercive behavior. We found phenotype-behavior matching whereby small males invest in putatively ornamental foreclaws used for courtship and large males invest in weaponry for coercion, challenging existing knowledge of this well-studied species. As a group with a long evolutionary history and varied mating systems, Testudines are a particularly interesting taxon in which to ask questions about mating system evolution. Significance statement Alternative Reproductive Tactics are hypothesized for long-lived species. We quantified a shift from apparent courtship to coercive Tactics during the Reproductive lifespan of a well-studied freshwater turtle. Male painted turtles ( Chrysemys picta ) have sexual weapons that are used to promote female acquiescence. Using behavioral trials with turtles from a long-term study population, we demonstrate that males match their morphology (ornament/weapons) to Reproductive behavior (courtship/coercion) as their Reproductive Tactics shift. Our findings hint at the behavioral complexity of aquatic turtles, a challenging and often-overlooked group in behavioral studies.
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Sex, shells, and weaponry: coercive Reproductive Tactics in the painted turtle, Chrysemys picta
Behavioral Ecology and Sociobiology, 2020Co-Authors: Patrick D. Moldowan, Ronald J. Brooks, Jacqueline D. LitzgusAbstract:Males and females have divergent Reproductive interests arising from their unequal investments in offspring. This sexual conflict drives an antagonistic arms race that influences sex-specific Reproductive success. Alternative Reproductive Tactics are expected in long-lived species for which the Reproductive strategy that maximizes mating success could differ across body sizes. The mating strategy of the painted turtle (Chrysemys picta) has been characterized as an elaborate and amiable male courtship display during which males use their elongate foreclaws to stroke females, coupled with female mate choice. Contrary to this long-held understanding, in situ field observations and experimental trials from our long-term study in Algonquin Provincial Park, Canada, demonstrate that males also exhibit an alternative, coercive mating strategy. Males are equipped with sexually size dimorphic tomiodonts, tooth-like cusps of the beak, as well as a weaponized anterior shell, with which they wound the head and neck of females. Behavioral trials during the breeding periods showed that male Reproductive Tactics shift from courtship (foreclaw display) to coercion (striking, biting, and forced submergence) across ontogeny, and male size predicts the occurrence and frequency of coercive behavior. We found phenotype-behavior matching whereby small males invest in putatively ornamental foreclaws used for courtship and large males invest in weaponry for coercion, challenging existing knowledge of this well-studied species. As a group with a long evolutionary history and varied mating systems, Testudines are a particularly interesting taxon in which to ask questions about mating system evolution. Alternative Reproductive Tactics are hypothesized for long-lived species. We quantified a shift from apparent courtship to coercive Tactics during the Reproductive lifespan of a well-studied freshwater turtle. Male painted turtles (Chrysemys picta) have sexual weapons that are used to promote female acquiescence. Using behavioral trials with turtles from a long-term study population, we demonstrate that males match their morphology (ornament/weapons) to Reproductive behavior (courtship/coercion) as their Reproductive Tactics shift. Our findings hint at the behavioral complexity of aquatic turtles, a challenging and often-overlooked group in behavioral studies.
Nicolas Fasel - One of the best experts on this subject based on the ideXlab platform.
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Experimental manipulation of Reproductive Tactics in Seba's short-tailed bats: consequences on sperm quality and oxidative status.
Current zoology, 2019Co-Authors: Magali Meniri, Florence Gohon, Ophélie Gning, Gaétan Glauser, Armelle Vallat, Nicolas Fasel, Fabrice HelfensteinAbstract:To reproduce, males have to fertilize the female's eggs, sometimes in competition with ejaculates of other males. In species where males display alternative Reproductive Tactics, whereby territorial males secure mating and non-territorial males have to sneak copulations, the latter might be expected to invest relatively more resources towards sperm quality compared with the territorial males. Sperm cells are especially vulnerable to oxidative stress, which reduces male fertility. Therefore, antioxidant resources are expected to modulate sperm quality, and might be allocated differently between Reproductive Tactics. To test the link between Reproductive Tactics, redox profile and sperm quality, we experimentally induced changes in the Reproductive Tactics of 39 captive males Seba's short-tailed bats Carollia perspicillata. We monitored the blood and ejaculate oxidative balance, and the sperm quality before, 7 days and 21 days after the manipulation of Reproductive tactic. Although ejaculates' oxidative damage was negatively related to sperm velocity, males exhibited similar blood and ejaculates redox profiles and similar sperm quality, regardless of their Reproductive tactic. Possibly, these results arise as a consequence of some constraints having been lifted during the experiment. Our results also suggest that, in Seba's short-tailed bats, the expression of alternative Reproductive Tactics is not subjected to strong oxidative constraints. Furthermore, our results could reflect an absence of trade-off between pre- and post-copulatory traits in harem males, as they could be selected to invest both in female attraction and sperm quality, as a consequence of their inability to fully monopolize females.
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alternative Reproductive Tactics sperm mobility and oxidative stress in carollia perspicillata seba s short tailed bat
Behavioral Ecology and Sociobiology, 2017Co-Authors: Gaétan Glauser, Armelle Vallat, Nicolas Fasel, Fabrice Helfenstein, Charlotte Wesseling, Ahana Aurora Fernandez, Heinz RichnerAbstract:In social systems with alternative Reproductive Tactics, sneakers face a higher level of sperm competition than harem males and hence are predicted to allocate more resources to ejaculates. Antioxidants can protect sperm against oxidative stress, and thus, their allocation to the ejaculate may depend on mating tactic. In this study on the frugivorous bat Carollia perspicillata, we assessed, for harem and sneaker males, four sperm mobility traits, blood and ejaculate markers of the redox balance and the ejaculate to blood ratios of the redox markers. Under higher sperm competition, sneaker males should allocate proportionally more antioxidant resources to the protection of sperm than harem males. In contrast, harem males should favour pre-copulatory functions, which comprise the protection of blood. We found significantly higher sperm velocity and sperm survival in sneakers. There was no correlation between sperm mobility and sperm enzymatic antioxidant activity or ejaculate levels of lipid peroxidation (oxidative damage). Ejaculate levels of lipid peroxidation and sperm survival showed a significantly positive correlation, which could be attributed to the role of reactive oxygen species for sperm capacitation. Harem and sneaker males showed similar levels of redox balance markers in ejaculate and blood. However, harem males showed a higher ratio of oxidized over reduced glutathione in blood, which may indicate higher cellular stress due to higher metabolism. Overall, our findings suggest that sneakers of C. perspicillata compensate for a higher level of sperm competition by higher sperm mobility. In social systems with alternative Reproductive Tactics, sneakers face higher level of sperm competition than harem males and hence are predicted to allocate more resources to ejaculates. Antioxidants can protect sperm against oxidative stress, and thus, their allocation to the ejaculate may depend on mating tactic. In this study on the frugivorous bat Carollia perspicillata, we found sperm swimming significantly faster and longer in sneaker males compared to harem males. However, traits other than the investigated antioxidant may favour higher sperm mobility. Measured redox pattern in blood of harem males may indicate higher cellular stress due to higher metabolism. Our results provide support to the current sperm competition models at the intraspecific level, which is still debated for internal fertilizers. This study contributes to better understanding the trade-offs and adaptations resulting from alternative Reproductive Tactics in mammals.
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Alternative Reproductive Tactics, sperm mobility and oxidative stress in Carollia perspicillata (Seba’s short-tailed bat)
Behavioral Ecology and Sociobiology, 2016Co-Authors: Nicolas Fasel, Gaétan Glauser, Armelle Vallat, Fabrice Helfenstein, Charlotte Wesseling, Ahana Aurora Fernandez, Heinz RichnerAbstract:In social systems with alternative Reproductive Tactics, sneakers face a higher level of sperm competition than harem males and hence are predicted to allocate more resources to ejaculates. Antioxidants can protect sperm against oxidative stress, and thus, their allocation to the ejaculate may depend on mating tactic. In this study on the frugivorous bat Carollia perspicillata, we assessed, for harem and sneaker males, four sperm mobility traits, blood and ejaculate markers of the redox balance and the ejaculate to blood ratios of the redox markers. Under higher sperm competition, sneaker males should allocate proportionally more antioxidant resources to the protection of sperm than harem males. In contrast, harem males should favour pre-copulatory functions, which comprise the protection of blood. We found significantly higher sperm velocity and sperm survival in sneakers. There was no correlation between sperm mobility and sperm enzymatic antioxidant activity or ejaculate levels of lipid peroxidation (oxidative damage). Ejaculate levels of lipid peroxidation and sperm survival showed a significantly positive correlation, which could be attributed to the role of reactive oxygen species for sperm capacitation. Harem and sneaker males showed similar levels of redox balance markers in ejaculate and blood. However, harem males showed a higher ratio of oxidized over reduced glutathione in blood, which may indicate higher cellular stress due to higher metabolism. Overall, our findings suggest that sneakers of C. perspicillata compensate for a higher level of sperm competition by higher sperm mobility. In social systems with alternative Reproductive Tactics, sneakers face higher level of sperm competition than harem males and hence are predicted to allocate more resources to ejaculates. Antioxidants can protect sperm against oxidative stress, and thus, their allocation to the ejaculate may depend on mating tactic. In this study on the frugivorous bat Carollia perspicillata, we found sperm swimming significantly faster and longer in sneaker males compared to harem males. However, traits other than the investigated antioxidant may favour higher sperm mobility. Measured redox pattern in blood of harem males may indicate higher cellular stress due to higher metabolism. Our results provide support to the current sperm competition models at the intraspecific level, which is still debated for internal fertilizers. This study contributes to better understanding the trade-offs and adaptations resulting from alternative Reproductive Tactics in mammals.
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Alternative Reproductive Tactics and Reproductive success in male Carollia perspicillata (Seba's short-tailed bat).
Journal of evolutionary biology, 2016Co-Authors: Nicolas Fasel, Verena Saladin, Heinz RichnerAbstract:The use of alternative Reproductive Tactics (ARTs) is widespread in animals. Males of some species may change Tactics depending on age, body condition and social environment. Many bat species are polygynous where a fraction of males only have access to fertile females. For polygynous bats, knowledge of the Reproductive success of males using different ARTs is scarce, and it remains unclear how age of males is related to switching decisions between social statuses. We studied a large captive population of Carollia perspicillata, where males are either harem holders, bachelors or peripheral males. Using a multistate procedure, we modelled the age-related switches in Reproductive Tactics and in survival probability. From the model, we calculated the Reproductive success and the frequencies of males displaying different Reproductive Tactics. As in mammals, the switch between social statuses is often related to age, we predicted that the transition probability of bachelor and peripheral males to harem status would increase with age. We show, however, that social status transition towards a harem holding position was not related to age. Reproductive success changed with age and social status. Harem males had a significantly higher Reproductive success than bachelor males except between a short period from 3.8 to 4.4 years of age where success was similar, and a significantly higher Reproductive success than peripheral males between 2.6 and 4.4 years of age. Harem males showed a clear decrease in the probability of maintaining social status with age, which suggests that senescence reduces resource holding potential.
Heinz Richner - One of the best experts on this subject based on the ideXlab platform.
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alternative Reproductive Tactics sperm mobility and oxidative stress in carollia perspicillata seba s short tailed bat
Behavioral Ecology and Sociobiology, 2017Co-Authors: Gaétan Glauser, Armelle Vallat, Nicolas Fasel, Fabrice Helfenstein, Charlotte Wesseling, Ahana Aurora Fernandez, Heinz RichnerAbstract:In social systems with alternative Reproductive Tactics, sneakers face a higher level of sperm competition than harem males and hence are predicted to allocate more resources to ejaculates. Antioxidants can protect sperm against oxidative stress, and thus, their allocation to the ejaculate may depend on mating tactic. In this study on the frugivorous bat Carollia perspicillata, we assessed, for harem and sneaker males, four sperm mobility traits, blood and ejaculate markers of the redox balance and the ejaculate to blood ratios of the redox markers. Under higher sperm competition, sneaker males should allocate proportionally more antioxidant resources to the protection of sperm than harem males. In contrast, harem males should favour pre-copulatory functions, which comprise the protection of blood. We found significantly higher sperm velocity and sperm survival in sneakers. There was no correlation between sperm mobility and sperm enzymatic antioxidant activity or ejaculate levels of lipid peroxidation (oxidative damage). Ejaculate levels of lipid peroxidation and sperm survival showed a significantly positive correlation, which could be attributed to the role of reactive oxygen species for sperm capacitation. Harem and sneaker males showed similar levels of redox balance markers in ejaculate and blood. However, harem males showed a higher ratio of oxidized over reduced glutathione in blood, which may indicate higher cellular stress due to higher metabolism. Overall, our findings suggest that sneakers of C. perspicillata compensate for a higher level of sperm competition by higher sperm mobility. In social systems with alternative Reproductive Tactics, sneakers face higher level of sperm competition than harem males and hence are predicted to allocate more resources to ejaculates. Antioxidants can protect sperm against oxidative stress, and thus, their allocation to the ejaculate may depend on mating tactic. In this study on the frugivorous bat Carollia perspicillata, we found sperm swimming significantly faster and longer in sneaker males compared to harem males. However, traits other than the investigated antioxidant may favour higher sperm mobility. Measured redox pattern in blood of harem males may indicate higher cellular stress due to higher metabolism. Our results provide support to the current sperm competition models at the intraspecific level, which is still debated for internal fertilizers. This study contributes to better understanding the trade-offs and adaptations resulting from alternative Reproductive Tactics in mammals.
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Alternative Reproductive Tactics, sperm mobility and oxidative stress in Carollia perspicillata (Seba’s short-tailed bat)
Behavioral Ecology and Sociobiology, 2016Co-Authors: Nicolas Fasel, Gaétan Glauser, Armelle Vallat, Fabrice Helfenstein, Charlotte Wesseling, Ahana Aurora Fernandez, Heinz RichnerAbstract:In social systems with alternative Reproductive Tactics, sneakers face a higher level of sperm competition than harem males and hence are predicted to allocate more resources to ejaculates. Antioxidants can protect sperm against oxidative stress, and thus, their allocation to the ejaculate may depend on mating tactic. In this study on the frugivorous bat Carollia perspicillata, we assessed, for harem and sneaker males, four sperm mobility traits, blood and ejaculate markers of the redox balance and the ejaculate to blood ratios of the redox markers. Under higher sperm competition, sneaker males should allocate proportionally more antioxidant resources to the protection of sperm than harem males. In contrast, harem males should favour pre-copulatory functions, which comprise the protection of blood. We found significantly higher sperm velocity and sperm survival in sneakers. There was no correlation between sperm mobility and sperm enzymatic antioxidant activity or ejaculate levels of lipid peroxidation (oxidative damage). Ejaculate levels of lipid peroxidation and sperm survival showed a significantly positive correlation, which could be attributed to the role of reactive oxygen species for sperm capacitation. Harem and sneaker males showed similar levels of redox balance markers in ejaculate and blood. However, harem males showed a higher ratio of oxidized over reduced glutathione in blood, which may indicate higher cellular stress due to higher metabolism. Overall, our findings suggest that sneakers of C. perspicillata compensate for a higher level of sperm competition by higher sperm mobility. In social systems with alternative Reproductive Tactics, sneakers face higher level of sperm competition than harem males and hence are predicted to allocate more resources to ejaculates. Antioxidants can protect sperm against oxidative stress, and thus, their allocation to the ejaculate may depend on mating tactic. In this study on the frugivorous bat Carollia perspicillata, we found sperm swimming significantly faster and longer in sneaker males compared to harem males. However, traits other than the investigated antioxidant may favour higher sperm mobility. Measured redox pattern in blood of harem males may indicate higher cellular stress due to higher metabolism. Our results provide support to the current sperm competition models at the intraspecific level, which is still debated for internal fertilizers. This study contributes to better understanding the trade-offs and adaptations resulting from alternative Reproductive Tactics in mammals.
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Alternative Reproductive Tactics and Reproductive success in male Carollia perspicillata (Seba's short-tailed bat).
Journal of evolutionary biology, 2016Co-Authors: Nicolas Fasel, Verena Saladin, Heinz RichnerAbstract:The use of alternative Reproductive Tactics (ARTs) is widespread in animals. Males of some species may change Tactics depending on age, body condition and social environment. Many bat species are polygynous where a fraction of males only have access to fertile females. For polygynous bats, knowledge of the Reproductive success of males using different ARTs is scarce, and it remains unclear how age of males is related to switching decisions between social statuses. We studied a large captive population of Carollia perspicillata, where males are either harem holders, bachelors or peripheral males. Using a multistate procedure, we modelled the age-related switches in Reproductive Tactics and in survival probability. From the model, we calculated the Reproductive success and the frequencies of males displaying different Reproductive Tactics. As in mammals, the switch between social statuses is often related to age, we predicted that the transition probability of bachelor and peripheral males to harem status would increase with age. We show, however, that social status transition towards a harem holding position was not related to age. Reproductive success changed with age and social status. Harem males had a significantly higher Reproductive success than bachelor males except between a short period from 3.8 to 4.4 years of age where success was similar, and a significantly higher Reproductive success than peripheral males between 2.6 and 4.4 years of age. Harem males showed a clear decrease in the probability of maintaining social status with age, which suggests that senescence reduces resource holding potential.
Bryan D. Neff - One of the best experts on this subject based on the ideXlab platform.
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Brain Transcriptional Profiles of Male Alternative Reproductive Tactics and Females in Bluegill Sunfish.
PloS one, 2016Co-Authors: Charlyn G. Partridge, Matthew D. Macmanes, Rosemary Knapp, Bryan D. NeffAbstract:Bluegill sunfish (Lepomis macrochirus) are one of the classic systems for studying male alternative Reproductive Tactics (ARTs) in teleost fishes. In this species, there are two distinct life histories: parental and cuckolder, encompassing three Reproductive Tactics, parental, satellite, and sneaker. The parental life history is fixed, whereas individuals who enter the cuckolder life history transition from sneaker to satellite tactic as they grow. For this study, we used RNAseq to characterize the brain transcriptome of the three male Tactics and females during spawning to identify gene ontology (GO) categories and potential candidate genes associated with each tactic. We found that sneaker males had higher levels of gene expression differentiation compared to the other two male Tactics. Sneaker males also had higher expression in ionotropic glutamate receptor genes, specifically AMPA receptors, compared to other males, which may be important for increased spatial working memory while attempting to cuckold parental males at their nests. Larger differences in gene expression also occurred among male Tactics than between males and females. We found significant expression differences in several candidate genes that were previously identified in other species with ARTs and suggest a previously undescribed role for cAMP-responsive element modulator (crem) in influencing parental male behaviors during spawning.
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brain transcriptional profiles of male alternative Reproductive Tactics and females in bluegill sunfish
bioRxiv, 2016Co-Authors: Charlyn G. Partridge, Matthew D. Macmanes, Rosemary Knapp, Bryan D. NeffAbstract:Bluegill sunfish are one of the classic systems for studying male alternative Reproductive Tactics (ARTs) in teleost fishes. In this species, there are two distinct life histories: parental and cuckolder, encompassing three Reproductive Tactics, parental, satellite, and sneaker. The parental life history is fixed, whereas individuals who enter the cuckolder life history transition from the sneaker to the satellite tactic as they grow. For this study, we used RNAseq to characterize the brain transcriptome of the three male Tactics and females during spawning to identify gene categories associated with each tactic and identify potential candidate genes influencing their different spawning behaviors. We found that sneaker males had higher levels of gene differentiation compared to the other two male Tactics. Sneaker males also had high expression in ionotropic glutamate receptor genes, specifically AMPA receptors, which may be important for increased working spatial memory while attempting to cuckold parental males at their nests. Larger differences in gene expression also occurred among male Tactics than between males and females. We found significant expression differences in several candidate genes that were previously identified in other species with ARTs and suggest a previously undescribed role for cAMP-responsive element modulator (crem) in influencing parental male behaviors during spawning.
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Brain Transcriptional Profiles of Male Alternative Reproductive Tactics in Bluegill Sunfish
2015Co-Authors: Charlyn G. Partridge, Matthew D. Macmanes, Rosemary Knapp, Bryan D. NeffAbstract:Bluegill sunfish are one of the classic systems for studying male alternative Reproductive Tactics (ARTs) in teleost fishes. In this species, there are two distinct life histories: parental and cuckolder, encompassing three Reproductive Tactics, parental, satellite, and sneaker. The parental tactic is fixed, whereas individuals who enter the cuckolder life history transition from the sneaker to the satellite tactic as they grow. For this study, we used RNAseq to characterize the brain transcriptome of the three male Tactics during spawning to identify gene categories associated with each tactic and identify potential candidate genes influencing their different spawning behaviors. We found that sneaker males had higher levels of gene differentiation compared to the other two Tactics, suggesting that life history does not exclusively drive differential gene expression. Sneaker males had high expression in ionotropic glutamate receptor genes, specifically AMPA receptors, which may be important for increased working spatial memory while attempting to cuckold nests in bluegill colonies. We also found significant expression differences in several candidate genes involved in ARTs that were previously identified in other species and suggest a previously undescribed role for cytosolic 5-nucleotidase II (nt5c2) in influencing parental male behavior during spawning.
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Alternative male Reproductive Tactics drive asymmetrical hybridization between sunfishes (Lepomis spp.).
Biology Letters, 2013Co-Authors: Shawn R. Garner, Bryan D. NeffAbstract:The potential role of alternative Reproductive Tactics in circumventing premating isolating mechanisms and driving hybridization between species has long been recognized, but to date there is little empirical support from natural systems. Hybridization occurs between bluegill (Lepomis macrochirus) and pumpkinseed sunfish (Lepomis gibbosus) and it is known to be asymmetrical (male bluegill × female pumpkinseed). Here, we test whether this pattern is driven by a recognition failure by pumpkinseed females or by an alternative cuckolder Reproductive tactic in bluegill males. Using genetic parentage data, we found that bluegill cuckolders fathered 24.9% of the larvae in bluegill nests, but no evidence that pumpkinseed females spawned in bluegill nests. Pumpkinseed cuckolders fathered 8.7% of the larvae in pumpkinseed nests, whereas bluegill cuckolders fathered 13.6% of the larvae in those nests. Bluegill cuckolders thus frequently spawn in pumpkinseed nests and are responsible for the asymmetrical hybridization between the species. We discuss the evolutionary consequences of interactions between bluegill and pumpkinseed and the role of alternative Reproductive Tactics in adaptation and introgression.
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Effects of foraging and sexual selection on ecomorphology of a fish with alternative Reproductive Tactics
Behavioral Ecology, 2013Co-Authors: Scott F. Colborne, Pedro R. Peres-neto, Fred J. Longstaffe, Bryan D. NeffAbstract:The foraging ecology of fish is often considered to be the primary determinant of body shape due to tight links between morphology, swimming performance, and foraging efficiency. Fish foraging on littoral benthic macroinvertebrates typically have a deeper body shape than those foraging on pelagic zooplankton in the water column. However, morphological traits often have multiple ecological functions, which could result in performance trade-offs between functions. Here, we provide the first examination of body shape and diet in a species with alternative Reproductive Tactics, in this case, bluegill sunfish (Lepomis macrochirus Rafinesque, 1819). Bluegill males mature into either "parental" or "cuckolder" Reproductive Tactics. Parentals build nests and provide sole parental care and defense of the young. Cuckolders instead act as "sneakers" darting into the nests of parental males while mating is occurring and then later in life become "satellites," mimicking female appearance and behavior. Using stable carbon and nitrogen isotopic analysis of diet, we found that parentals and females consumed primarily pelagic zooplankton yet were the deepest in body shape. Sneakers consumed more littoral resources but were the most streamlined. Satellite males also consumed predominately littoral resources but had a deeper body form that was more similar to females than to size-matched juveniles. Our results differ from past studies of foraging ecomorphology and suggest that other selection pressures, such as sexual selection in species with alternative Reproductive Tactics, may also be an important factor influencing shape.
Patrick D. Moldowan - One of the best experts on this subject based on the ideXlab platform.
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Sex, shells, and weaponry: coercive Reproductive Tactics in the painted turtle, Chrysemys picta
Behavioral Ecology and Sociobiology, 2020Co-Authors: Patrick D. Moldowan, Ronald J. Brooks, Jacqueline D. LitzgusAbstract:Males and females have divergent Reproductive interests arising from their unequal investments in offspring. This sexual conflict drives an antagonistic arms race that influences sex-specific Reproductive success. Alternative Reproductive Tactics are expected in long-lived species for which the Reproductive strategy that maximizes mating success could differ across body sizes. The mating strategy of the painted turtle ( Chrysemys picta ) has been characterized as an elaborate and amiable male courtship display during which males use their elongate foreclaws to stroke females, coupled with female mate choice. Contrary to this long-held understanding, in situ field observations and experimental trials from our long-term study in Algonquin Provincial Park, Canada, demonstrate that males also exhibit an alternative, coercive mating strategy. Males are equipped with sexually size dimorphic tomiodonts, tooth-like cusps of the beak, as well as a weaponized anterior shell, with which they wound the head and neck of females. Behavioral trials during the breeding periods showed that male Reproductive Tactics shift from courtship (foreclaw display) to coercion (striking, biting, and forced submergence) across ontogeny, and male size predicts the occurrence and frequency of coercive behavior. We found phenotype-behavior matching whereby small males invest in putatively ornamental foreclaws used for courtship and large males invest in weaponry for coercion, challenging existing knowledge of this well-studied species. As a group with a long evolutionary history and varied mating systems, Testudines are a particularly interesting taxon in which to ask questions about mating system evolution. Significance statement Alternative Reproductive Tactics are hypothesized for long-lived species. We quantified a shift from apparent courtship to coercive Tactics during the Reproductive lifespan of a well-studied freshwater turtle. Male painted turtles ( Chrysemys picta ) have sexual weapons that are used to promote female acquiescence. Using behavioral trials with turtles from a long-term study population, we demonstrate that males match their morphology (ornament/weapons) to Reproductive behavior (courtship/coercion) as their Reproductive Tactics shift. Our findings hint at the behavioral complexity of aquatic turtles, a challenging and often-overlooked group in behavioral studies.
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Sex, shells, and weaponry: coercive Reproductive Tactics in the painted turtle, Chrysemys picta
Behavioral Ecology and Sociobiology, 2020Co-Authors: Patrick D. Moldowan, Ronald J. Brooks, Jacqueline D. LitzgusAbstract:Males and females have divergent Reproductive interests arising from their unequal investments in offspring. This sexual conflict drives an antagonistic arms race that influences sex-specific Reproductive success. Alternative Reproductive Tactics are expected in long-lived species for which the Reproductive strategy that maximizes mating success could differ across body sizes. The mating strategy of the painted turtle (Chrysemys picta) has been characterized as an elaborate and amiable male courtship display during which males use their elongate foreclaws to stroke females, coupled with female mate choice. Contrary to this long-held understanding, in situ field observations and experimental trials from our long-term study in Algonquin Provincial Park, Canada, demonstrate that males also exhibit an alternative, coercive mating strategy. Males are equipped with sexually size dimorphic tomiodonts, tooth-like cusps of the beak, as well as a weaponized anterior shell, with which they wound the head and neck of females. Behavioral trials during the breeding periods showed that male Reproductive Tactics shift from courtship (foreclaw display) to coercion (striking, biting, and forced submergence) across ontogeny, and male size predicts the occurrence and frequency of coercive behavior. We found phenotype-behavior matching whereby small males invest in putatively ornamental foreclaws used for courtship and large males invest in weaponry for coercion, challenging existing knowledge of this well-studied species. As a group with a long evolutionary history and varied mating systems, Testudines are a particularly interesting taxon in which to ask questions about mating system evolution. Alternative Reproductive Tactics are hypothesized for long-lived species. We quantified a shift from apparent courtship to coercive Tactics during the Reproductive lifespan of a well-studied freshwater turtle. Male painted turtles (Chrysemys picta) have sexual weapons that are used to promote female acquiescence. Using behavioral trials with turtles from a long-term study population, we demonstrate that males match their morphology (ornament/weapons) to Reproductive behavior (courtship/coercion) as their Reproductive Tactics shift. Our findings hint at the behavioral complexity of aquatic turtles, a challenging and often-overlooked group in behavioral studies.
