L. Page, J. Pfeiffer, S. Suksri, Z. Randall, David A. Boyd
Analyses of morphological and molecular data from recently collected specimens of Nemacheilus from Cambodia, Malaysia, and Thailand indicate that N. pallidus is a junior synonym of N. masyae, and an undescribed species of Nemacheilus occurs in large tributaries of the Mekong River in Thailand. The new species, described herein, is small—with a maximum-known standard length of 28.6 mm—and has a distinctive color pattern of dusky black bars along the side of the body that cross over the back and join the bars on the other side. Molecular phylogenetic analyses suggest that the new species is most closely related to N. masyae , which reaches a much larger size—to 66.2 mm SL—and otherwise is easily distinguished from the new species. The new species is known from the Songkhram and Mun river drainages in Thailand and appears to be restricted to the Khorat Plateau ecoregion of the Mekong River basin. Nemacheilus masyae occurs throughout mainland southeast Asia, including in the Chao Phraya, Mae Klong, Mekong, and coastal drainages of the Malay Peninsula.
{"title":"Variation in the Arrow Loach, Nemacheilus masyae (Cypriniformes: Nemacheilidae), in Mainland Southeast Asia with Description of a New Species","authors":"L. Page, J. Pfeiffer, S. Suksri, Z. Randall, David A. Boyd","doi":"10.1643/CI-19-305","DOIUrl":"https://doi.org/10.1643/CI-19-305","url":null,"abstract":"Analyses of morphological and molecular data from recently collected specimens of Nemacheilus from Cambodia, Malaysia, and Thailand indicate that N. pallidus is a junior synonym of N. masyae, and an undescribed species of Nemacheilus occurs in large tributaries of the Mekong River in Thailand. The new species, described herein, is small—with a maximum-known standard length of 28.6 mm—and has a distinctive color pattern of dusky black bars along the side of the body that cross over the back and join the bars on the other side. Molecular phylogenetic analyses suggest that the new species is most closely related to N. masyae , which reaches a much larger size—to 66.2 mm SL—and otherwise is easily distinguished from the new species. The new species is known from the Songkhram and Mun river drainages in Thailand and appears to be restricted to the Khorat Plateau ecoregion of the Mekong River basin. Nemacheilus masyae occurs throughout mainland southeast Asia, including in the Chao Phraya, Mae Klong, Mekong, and coastal drainages of the Malay Peninsula.","PeriodicalId":10701,"journal":{"name":"Copeia","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2020-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41301708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Konvalina, J. W. Stanley, S. Trauth, M. Plummer
Vast differences in available resources between habitats can have profound influences on aspects of an organism's life history, such as reproductive investment. Our study investigated how differences in nutrient availability affect sperm size in Diamond-backed Watersnakes (Nerodia rhombifer). We compared body size and sperm morphometrics between two populations with differing nutrient availability: a naturally occurring lake and a commercial fish farm. We hypothesized that prey availability affects sperm morphometrics. Our null hypothesis was that there would be no significant difference in sperm morphometrics between populations, whereas our alternative hypothesis was that the snakes from the fish farm would have significantly longer sperm. We measured total sperm length, sperm head length, sperm tail length, and snout–vent length (SVL). We then used two-tailed t-tests and AIC model selection to test our hypotheses. SVL was not correlated with sperm size. Furthermore, none of the sperm morphometrics were significantly different between the two populations. Finally, a nearly 1:1 correlation between sperm tail length and total sperm length was found. AIC model selection corroborated these results by choosing only sperm head length and sperm tail length as significant predictors of total sperm length. This is the first published study to explicitly compare sperm morphometrics between two populations of the same snake species. Additional studies of this nature are required to corroborate whether lack of significant differences in sperm morphometrics among snake populations are common.
{"title":"No Sperm Morphometric Differences between Two Populations of Diamond-backed Watersnakes (Nerodia rhombifer) with Varying Resource Availability","authors":"J. Konvalina, J. W. Stanley, S. Trauth, M. Plummer","doi":"10.1643/CG-17-692","DOIUrl":"https://doi.org/10.1643/CG-17-692","url":null,"abstract":"Vast differences in available resources between habitats can have profound influences on aspects of an organism's life history, such as reproductive investment. Our study investigated how differences in nutrient availability affect sperm size in Diamond-backed Watersnakes (Nerodia rhombifer). We compared body size and sperm morphometrics between two populations with differing nutrient availability: a naturally occurring lake and a commercial fish farm. We hypothesized that prey availability affects sperm morphometrics. Our null hypothesis was that there would be no significant difference in sperm morphometrics between populations, whereas our alternative hypothesis was that the snakes from the fish farm would have significantly longer sperm. We measured total sperm length, sperm head length, sperm tail length, and snout–vent length (SVL). We then used two-tailed t-tests and AIC model selection to test our hypotheses. SVL was not correlated with sperm size. Furthermore, none of the sperm morphometrics were significantly different between the two populations. Finally, a nearly 1:1 correlation between sperm tail length and total sperm length was found. AIC model selection corroborated these results by choosing only sperm head length and sperm tail length as significant predictors of total sperm length. This is the first published study to explicitly compare sperm morphometrics between two populations of the same snake species. Additional studies of this nature are required to corroborate whether lack of significant differences in sperm morphometrics among snake populations are common.","PeriodicalId":10701,"journal":{"name":"Copeia","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2020-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43806630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new species of Hyphessobrycon from a tributary of the Rio Paru do Oeste (Rio Trombetas basin), at the lower Amazon basin draining the Guiana Shield region in Pará State, Brazil, is described. The new species presents a unique combination of an irregularly-shaped humeral blotch, a broad diffuse midlateral stripe, and a roughly triangular caudal peduncle blotch. The new species is herein included in the Hyphessobrycon agulha species-group, and comparisons with species belonging to this group and to a similar-looking non-congener, Hemigrammus bellottii, are presented.
描述了巴西帕拉州圭亚那地盾区下游亚马逊盆地Rio Paru do Oeste（Rio Trombetas盆地）支流Hyphessobrycon的一个新种。新物种呈现出一种独特的组合，包括不规则形状的肱骨斑点、宽的弥漫性中侧条纹和大致三角形的尾柄斑点。本文将该新物种纳入Hyphessobrycon agulha物种群，并将其与属于该群的物种以及长相相似的非同源物种——贝洛蒂半球赤眼蜂进行了比较。
{"title":"A New Hyphessobrycon (Characiformes: Characidae) from the Guiana Shield in Northern Brazil","authors":"T. C. Faria, F. Lima, W. B. Wosiacki","doi":"10.1643/CI-19-311","DOIUrl":"https://doi.org/10.1643/CI-19-311","url":null,"abstract":"A new species of Hyphessobrycon from a tributary of the Rio Paru do Oeste (Rio Trombetas basin), at the lower Amazon basin draining the Guiana Shield region in Pará State, Brazil, is described. The new species presents a unique combination of an irregularly-shaped humeral blotch, a broad diffuse midlateral stripe, and a roughly triangular caudal peduncle blotch. The new species is herein included in the Hyphessobrycon agulha species-group, and comparisons with species belonging to this group and to a similar-looking non-congener, Hemigrammus bellottii, are presented.","PeriodicalId":10701,"journal":{"name":"Copeia","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2020-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1643/CI-19-311","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45661314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. J. Oswald, Emily Spinks, Garrett S. Duktig, Justin S. Baker, Marc R. Kibbey, Brian Zimmerman, H. Tucker, C. Boucher, D. Cincotta, W. Starnes, A. Kiss, Jeremy J. Wright, D. Carlson, M. Bangs, M. Roberts, J. Quattro
Legacies of ancient riverine systems are often manifest in patterns of genetic diversity within aquatic species. The ancient Teays River, a principal drainage of the eastern United States, engaged in several ephemeral connections with neighboring palaeodrainages prior to and during the Pleistocene, when cyclical glacial advance and retreat reconfigured the region's fluvial systems. This study assayed DNA-sequence diversity at one mitochondrial (mtDNA) and three single-copy nuclear DNA (scnDNA) loci from the Tonguetied Minnow (Exoglossum laurae), a species distributed as four disjunct populations, one each within the Upper Great Miami, Upper Allegheny, Upper Genesee, and New rivers. Mitochondrial DNA variation revealed that the New River harbors the highest diversity (h = 0.73) and that the Tonguetied Minnow is composed of two ancient lineages, a Teays River lineage and a Pittsburgh River lineage. Analyses of the scnDNA loci revealed sharing of alleles among populations of E. laurae and between the Tonguetied Minnow and its only congener, the Cutlip Minnow (E. maxillingua), sampled from the Roanoke and Potomac rivers. The probability of interspecific hybridization in the New and Upper Genesee rivers was estimated as 0.16 and 0.34, respectively, but it is likely that some degree of incomplete lineage sorting contributed to these estimates. Probabilities of interspecific hybridization for Cutlip Minnow were 0.62 and 0.65, for the Roanoke and Potomac rivers, respectively, and might reflect ancient hybridization resulting from stream capture events involving these drainages by the Teays River. Management strategies should focus on maintaining the security of the Pittsburgh River lineage in the Upper Great Miami and Upper Allegheny River drainages. Finally, insights into the Tonguetied Minnow's rather convoluted taxonomic history are few, but genetic variation is inconsistent with subspecies status for Tonguetied Minnow in the Upper Great Miami River drainage.
古代河流系统的遗产往往表现为水生物种的遗传多样性模式。古提斯河是美国东部的主要河流，在更新世之前和更新世期间，它与邻近的古河流有过几次短暂的联系，当时周期性的冰川前进和后退重新配置了该地区的河流系统。本研究分析了舌结鲦鱼(Exoglossum laurae)的一个线粒体(mtDNA)和三个单拷贝核DNA (scnDNA)位点的DNA序列多样性，舌结鲦鱼(Exoglossum laurae)是一个分布在大迈阿密河上游、阿勒格尼河上游、Genesee河上游和新河流域的四个不相连种群。线粒体DNA变异表明，新河拥有最高的多样性(h = 0.73)，舌系鲦鱼由两个古老的谱系组成，一个Teays河谱系和一个匹兹堡河谱系。对scnDNA位点的分析显示，在laurae种群中，以及在Roanoke河和Potomac河取样的舌纹米诺与其唯一的同系者Cutlip Minnow (E. maxillingua)之间，等位基因是共享的。据估计，新河和上Genesee河种间杂交的概率分别为0.16和0.34，但可能是某种程度上不完整的谱系分类导致了这些估计。在Roanoke河和Potomac河中，Cutlip Minnow的种间杂交概率分别为0.62和0.65，这可能反映了Teays河流域的河流捕获事件导致的古代杂交。管理策略应侧重于维护大迈阿密河上游和阿勒格尼河上游流域匹兹堡河流域的安全。最后，关于舌结米诺相当复杂的分类历史的见解很少，但是遗传变异与大迈阿密河上游流域舌结米诺的亚种地位不一致。
{"title":"Drainage History, Evolution, and Conservation of Tonguetied Minnow (Exoglossum laurae), a Rare and Imperiled Teays River Endemic","authors":"K. J. Oswald, Emily Spinks, Garrett S. Duktig, Justin S. Baker, Marc R. Kibbey, Brian Zimmerman, H. Tucker, C. Boucher, D. Cincotta, W. Starnes, A. Kiss, Jeremy J. Wright, D. Carlson, M. Bangs, M. Roberts, J. Quattro","doi":"10.1643/CI-18-118","DOIUrl":"https://doi.org/10.1643/CI-18-118","url":null,"abstract":"Legacies of ancient riverine systems are often manifest in patterns of genetic diversity within aquatic species. The ancient Teays River, a principal drainage of the eastern United States, engaged in several ephemeral connections with neighboring palaeodrainages prior to and during the Pleistocene, when cyclical glacial advance and retreat reconfigured the region's fluvial systems. This study assayed DNA-sequence diversity at one mitochondrial (mtDNA) and three single-copy nuclear DNA (scnDNA) loci from the Tonguetied Minnow (Exoglossum laurae), a species distributed as four disjunct populations, one each within the Upper Great Miami, Upper Allegheny, Upper Genesee, and New rivers. Mitochondrial DNA variation revealed that the New River harbors the highest diversity (h = 0.73) and that the Tonguetied Minnow is composed of two ancient lineages, a Teays River lineage and a Pittsburgh River lineage. Analyses of the scnDNA loci revealed sharing of alleles among populations of E. laurae and between the Tonguetied Minnow and its only congener, the Cutlip Minnow (E. maxillingua), sampled from the Roanoke and Potomac rivers. The probability of interspecific hybridization in the New and Upper Genesee rivers was estimated as 0.16 and 0.34, respectively, but it is likely that some degree of incomplete lineage sorting contributed to these estimates. Probabilities of interspecific hybridization for Cutlip Minnow were 0.62 and 0.65, for the Roanoke and Potomac rivers, respectively, and might reflect ancient hybridization resulting from stream capture events involving these drainages by the Teays River. Management strategies should focus on maintaining the security of the Pittsburgh River lineage in the Upper Great Miami and Upper Allegheny River drainages. Finally, insights into the Tonguetied Minnow's rather convoluted taxonomic history are few, but genetic variation is inconsistent with subspecies status for Tonguetied Minnow in the Upper Great Miami River drainage.","PeriodicalId":10701,"journal":{"name":"Copeia","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2020-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46783765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A second species of Acanthobunocephalus is described from tributaries of the lower Purus River in the Amazon Basin, Brazil. Acanthobunocephalus scruggsi, new species, is distinguished from all other aspredinid species by its reduced number of fin rays: four pectoral-fin rays (vs. five or more), two dorsal-fin rays (vs. three or more, except Amaralia hypsiura), five pelvic-fin rays (vs. six), four to five anal-fin rays (vs. six or more, except Bunocephalus verrucosus), and nine caudal-fin rays (vs. 10, except Hoplomyzontinae, Amaralia, Platystacus, Bunocephalus chamaizelus, and Bunocephalus minerim). Osteological aspects of the new species of Acanthobunocephalus are described using cleared and stained specimens and high-resolution x-ray computed tomography (HRXCT), and compared with Acanthobunocephalus nicoi and other aspredinids. Generic assignment is based on putative apomorphic shared features and a morphological diagnosis for Acanthobunocephalus is presented.
{"title":"A New Miniature Species of Acanthobunocephalus (Silurifomes: Aspredinidae) from the Lower Purus River Basin, Amazon Basin, Brazil","authors":"T. P. Carvalho, R. Reis","doi":"10.1643/CI-19-309","DOIUrl":"https://doi.org/10.1643/CI-19-309","url":null,"abstract":"A second species of Acanthobunocephalus is described from tributaries of the lower Purus River in the Amazon Basin, Brazil. Acanthobunocephalus scruggsi, new species, is distinguished from all other aspredinid species by its reduced number of fin rays: four pectoral-fin rays (vs. five or more), two dorsal-fin rays (vs. three or more, except Amaralia hypsiura), five pelvic-fin rays (vs. six), four to five anal-fin rays (vs. six or more, except Bunocephalus verrucosus), and nine caudal-fin rays (vs. 10, except Hoplomyzontinae, Amaralia, Platystacus, Bunocephalus chamaizelus, and Bunocephalus minerim). Osteological aspects of the new species of Acanthobunocephalus are described using cleared and stained specimens and high-resolution x-ray computed tomography (HRXCT), and compared with Acanthobunocephalus nicoi and other aspredinids. Generic assignment is based on putative apomorphic shared features and a morphological diagnosis for Acanthobunocephalus is presented.","PeriodicalId":10701,"journal":{"name":"Copeia","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2020-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1643/CI-19-309","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48204310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Marsh, Alexa Caffio-Learner, Anna M. Daccache, Margaret B. Dewing, Kathryn L. McCreary, Nathan J. Richendollar, F. Skinner
Range limits can be caused by a multitude of abiotic or biotic factors, but all of these must act through the demography of range-edge populations. Woodland salamanders of the genus Plethodon often exhibit distinct range boundaries where the distributions of competing species meet. Because of their high densities and low mobility, Plethodon are well suited for studies of how fitness-related traits change as species approach their range limits. Across contact zones between the mountaintop endemic Peaks of Otter Salamander (Plethodon hubrichti) and the widespread Eastern Redback Salamander (Plethodon cinereus), we measured changes in three salamander traits: 1) body condition, 2) frequency of tail loss, and 3) proportion of hatchlings. We then used hierarchical Bayesian models to compare these traits among five site types: allopatric sites for both species, sites where one of the species was dominant and the other was rare, and mixed sites containing high densities of both species. For P. hubrichti, we found no consistent changes in body condition across contact zones. However, frequency of tail loss increased continuously from allopatric sites (21%) to rare sites (54%). We also found evidence of reduced hatchling proportions at sites outside of allopatric areas (15–16% versus 30% at allopatric sites). For P. cinereus, body condition was higher at allopatric sites compared to sites within the contact zone. Similar to P. hubrichti, frequency of tail loss in P. cinereus increased continuously from allopatric sites (27%) to sites where P. cinereus were rare (50%). However, for P. cinereus, we did not find evidence of reduced hatchling numbers towards the edge of their range margin. Overall, our results suggest that both species likely have reduced fitness as they approach their range margin. Tail loss, which may reflect interference competition, effects of predation, or interactions between these, could potentially act as a density-dependent factor that stabilizes the range boundary between these species, at least over shorter time scales.
{"title":"Range Limits and Demography of a Mountaintop Endemic Salamander and Its Widespread Competitor","authors":"D. Marsh, Alexa Caffio-Learner, Anna M. Daccache, Margaret B. Dewing, Kathryn L. McCreary, Nathan J. Richendollar, F. Skinner","doi":"10.1643/CE-19-223","DOIUrl":"https://doi.org/10.1643/CE-19-223","url":null,"abstract":"Range limits can be caused by a multitude of abiotic or biotic factors, but all of these must act through the demography of range-edge populations. Woodland salamanders of the genus Plethodon often exhibit distinct range boundaries where the distributions of competing species meet. Because of their high densities and low mobility, Plethodon are well suited for studies of how fitness-related traits change as species approach their range limits. Across contact zones between the mountaintop endemic Peaks of Otter Salamander (Plethodon hubrichti) and the widespread Eastern Redback Salamander (Plethodon cinereus), we measured changes in three salamander traits: 1) body condition, 2) frequency of tail loss, and 3) proportion of hatchlings. We then used hierarchical Bayesian models to compare these traits among five site types: allopatric sites for both species, sites where one of the species was dominant and the other was rare, and mixed sites containing high densities of both species. For P. hubrichti, we found no consistent changes in body condition across contact zones. However, frequency of tail loss increased continuously from allopatric sites (21%) to rare sites (54%). We also found evidence of reduced hatchling proportions at sites outside of allopatric areas (15–16% versus 30% at allopatric sites). For P. cinereus, body condition was higher at allopatric sites compared to sites within the contact zone. Similar to P. hubrichti, frequency of tail loss in P. cinereus increased continuously from allopatric sites (27%) to sites where P. cinereus were rare (50%). However, for P. cinereus, we did not find evidence of reduced hatchling numbers towards the edge of their range margin. Overall, our results suggest that both species likely have reduced fitness as they approach their range margin. Tail loss, which may reflect interference competition, effects of predation, or interactions between these, could potentially act as a density-dependent factor that stabilizes the range boundary between these species, at least over shorter time scales.","PeriodicalId":10701,"journal":{"name":"Copeia","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2020-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49449261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Predation can have strong effects on the structure of pond-breeding amphibian communities. Many factors can influence the outcome of predator–prey interactions, including differences in densities, identities, and body sizes of both predator and prey. These different mediating factors can impart synergistic impacts on predation rates, though distinguishing such interactions among multiple factors are underexplored. We examined whether different body sizes of two predators, larval Marbled Salamanders (Ambystoma opacum) and adult Lesser Sirens (Siren intermedia), varied in their ability to forage on larval anurans across a range of prey densities. We specifically tested whether attack rates and handling times, the two main parameters of functional response models, varied across three size classes in both predator species. We found that larval Marbled Salamanders exhibited a Type II (saturating) functional response and that larger individuals had higher attack rates and shorter handling times, resulting in greater prey mortality at higher prey densities with larger predators. In contrast, Lesser Sirens were largely ineffective predators despite being an order of magnitude larger in body size than Marbled Salamanders; tadpole mortality was largely unrelated to their own density. Predator body size was a significant predictor of prey mortality for both predator species. Overall, our study shows that species identity could be as important as predator body size when predicting the outcomes of predator–prey interactions.
{"title":"Functional Responses of Larval Marbled Salamanders (Ambystoma opacum) and Adult Lesser Sirens (Siren intermedia) on Anuran Tadpole Prey","authors":"T. Anderson, K. M. Stemp, J. Davenport","doi":"10.1643/CE-19-212","DOIUrl":"https://doi.org/10.1643/CE-19-212","url":null,"abstract":"Predation can have strong effects on the structure of pond-breeding amphibian communities. Many factors can influence the outcome of predator–prey interactions, including differences in densities, identities, and body sizes of both predator and prey. These different mediating factors can impart synergistic impacts on predation rates, though distinguishing such interactions among multiple factors are underexplored. We examined whether different body sizes of two predators, larval Marbled Salamanders (Ambystoma opacum) and adult Lesser Sirens (Siren intermedia), varied in their ability to forage on larval anurans across a range of prey densities. We specifically tested whether attack rates and handling times, the two main parameters of functional response models, varied across three size classes in both predator species. We found that larval Marbled Salamanders exhibited a Type II (saturating) functional response and that larger individuals had higher attack rates and shorter handling times, resulting in greater prey mortality at higher prey densities with larger predators. In contrast, Lesser Sirens were largely ineffective predators despite being an order of magnitude larger in body size than Marbled Salamanders; tadpole mortality was largely unrelated to their own density. Predator body size was a significant predictor of prey mortality for both predator species. Overall, our study shows that species identity could be as important as predator body size when predicting the outcomes of predator–prey interactions.","PeriodicalId":10701,"journal":{"name":"Copeia","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2020-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45577201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xochitl Ortiz-Ross, Michelle E. Thompson, Enrique Salicetti-Nelson, Orlando Vargas-Ramirez, M. A. Donnelly
Oviposition site selection is critical for the reproductive success of oviparous organisms. We investigated oviposition site selection in three species of glass frogs—Espadarana prosoblepon, Hyalinobatrachium valerioi, and Teratohyla spinosa—in northeastern Costa Rica. We conducted nocturnal visual encounter surveys to estimate glass frog egg mass abundance and characterize oviposition site features in streams of three different habitats (pasture, secondary forest, and mature forest). Our results show differential oviposition site selection among all three species depending on vegetation and stream features. Hyalinobatrachium valerioi and T. spinosa, which oviposit almost exclusively on the underside of leaves, selected smooth leaves, while E. prosoblepon, which oviposits on the upper side of leaves or in moss, used moss eight times more than expected on the basis of availability. Hyalinobatrachium valerioi was found on larger leaves than T. spinosa and E. prosoblepon. Teratohyla spinosa and E. prosoblepon both oviposited most frequently above slow-moving water, while H. valerioi oviposited most frequently above fast-moving water. Espadarana prosoblepon was the only species affected by habitat type and had higher abundances of egg masses in mature forest than in secondary forest and pasture. Our results suggest that microhabitat plays a larger role in oviposition site selection than larger habitat classification. We propose that appropriate riparian microhabitat is a critical factor in sustaining glass frog populations in modified habitats and highlight the importance of preserving riparian corridors in altered landscapes.
{"title":"Oviposition Site Selection in Three Glass Frog Species","authors":"Xochitl Ortiz-Ross, Michelle E. Thompson, Enrique Salicetti-Nelson, Orlando Vargas-Ramirez, M. A. Donnelly","doi":"10.1643/CE-19-243","DOIUrl":"https://doi.org/10.1643/CE-19-243","url":null,"abstract":"Oviposition site selection is critical for the reproductive success of oviparous organisms. We investigated oviposition site selection in three species of glass frogs—Espadarana prosoblepon, Hyalinobatrachium valerioi, and Teratohyla spinosa—in northeastern Costa Rica. We conducted nocturnal visual encounter surveys to estimate glass frog egg mass abundance and characterize oviposition site features in streams of three different habitats (pasture, secondary forest, and mature forest). Our results show differential oviposition site selection among all three species depending on vegetation and stream features. Hyalinobatrachium valerioi and T. spinosa, which oviposit almost exclusively on the underside of leaves, selected smooth leaves, while E. prosoblepon, which oviposits on the upper side of leaves or in moss, used moss eight times more than expected on the basis of availability. Hyalinobatrachium valerioi was found on larger leaves than T. spinosa and E. prosoblepon. Teratohyla spinosa and E. prosoblepon both oviposited most frequently above slow-moving water, while H. valerioi oviposited most frequently above fast-moving water. Espadarana prosoblepon was the only species affected by habitat type and had higher abundances of egg masses in mature forest than in secondary forest and pasture. Our results suggest that microhabitat plays a larger role in oviposition site selection than larger habitat classification. We propose that appropriate riparian microhabitat is a critical factor in sustaining glass frog populations in modified habitats and highlight the importance of preserving riparian corridors in altered landscapes.","PeriodicalId":10701,"journal":{"name":"Copeia","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2020-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1643/CE-19-243","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48486065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Predators can affect the development, fitness, and behavior of prey species in myriad ways. In response to the threat of predation, tadpoles can alter growth rate, morphology, and foraging behavior. Changes to tadpole development have the potential to alter life history characteristics and are therefore of interest in species of conservation concern. Using experimental mesocosms, we explored how non-lethal predators affected the larval development of the Pine Barrens Treefrog, Hyla andersonii, a near-threatened species in the United States. We found that caged dragonflies (Anax junius) induced darker tail coloration and deeper tail fins in tadpoles of H. andersonii, but the dragonflies did not affect tadpole behavior, survival, or size at metamorphosis. Non-lethal predator presence also induced greater within population variation in the tail color trait compared to populations without predators. This result suggests that there may be underlying genetic variation in the ability to express phenotypically plastic traits, a concept that should be explored further because it has implications for the evolution of inducible defenses. These findings support the existence of an adaptive syndrome among hylid tadpoles, where tadpoles develop conspicuous tail morphology in response to larval dragonfly predators.
{"title":"Predators Induce Morphological Changes in Tadpoles of Hyla andersonii","authors":"Ariel Kruger, P. Morin","doi":"10.1643/CE-19-241","DOIUrl":"https://doi.org/10.1643/CE-19-241","url":null,"abstract":"Predators can affect the development, fitness, and behavior of prey species in myriad ways. In response to the threat of predation, tadpoles can alter growth rate, morphology, and foraging behavior. Changes to tadpole development have the potential to alter life history characteristics and are therefore of interest in species of conservation concern. Using experimental mesocosms, we explored how non-lethal predators affected the larval development of the Pine Barrens Treefrog, Hyla andersonii, a near-threatened species in the United States. We found that caged dragonflies (Anax junius) induced darker tail coloration and deeper tail fins in tadpoles of H. andersonii, but the dragonflies did not affect tadpole behavior, survival, or size at metamorphosis. Non-lethal predator presence also induced greater within population variation in the tail color trait compared to populations without predators. This result suggests that there may be underlying genetic variation in the ability to express phenotypically plastic traits, a concept that should be explored further because it has implications for the evolution of inducible defenses. These findings support the existence of an adaptive syndrome among hylid tadpoles, where tadpoles develop conspicuous tail morphology in response to larval dragonfly predators.","PeriodicalId":10701,"journal":{"name":"Copeia","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2020-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42377566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Shepherd, H. Pinheiro, Tyler A. Y. Phelps, Erin E. Easton, A. Pérez‐Matus, L. Rocha
A new species of Chromis (Teleostei: Pomacentridae) is described from three specimens collected at 90 m depth in a mesophotic coral ecosystem at Rapa Nui, Chile. Chromis mamatapara, new species, can be distinguished from its congeners by the following combination of characters: dorsal-fin rays XIV,13–14; pectoral-fin rays 18–19, third from top of fin longest; tubed lateral-line scales 18; total gill rakers on first arch 30–32; vertebrae 11+15; and by coloration of living specimens, especially the presence of a single, pronounced, white spot, roughly the same diameter as the orbit, located where the posterior base of the dorsal fin intersects the caudal peduncle. The most similar DNA barcode (mitochondrial COI gene), among those available, is Chromis tingting from Japan (3.5% uncorrected divergence); however, C. mamatapara, new species, also superficially resembles other species for which sequences are unavailable for comparisons, including C. okamurai from Japan and C. struhsakeri from Hawaii. Due to the high geographic isolation and consequently high endemism in the Rapa Nui region, we believe that C. mamatapara, new species, is endemic to mesophotic ecosystems of Rapa Nui, Isla Salas y Gómez, and nearby seamounts, a discovery that contributes to the high endemism of the region and thus the need for conservation efforts.
在智利Rapa Nui的一个中孔珊瑚生态系统中，从90 m深度采集的三个标本中描述了一种新的Chromis (Teleostei: Pomacentridae)。新种mamatapara可通过以下特征组合与同属物种区分:背鳍射线XIV, 13-14;胸鳍射线18-19，从鳍的顶部第三最长;管状横向刻度18;上弓鳃耙总数30-32;椎骨11 + 15;通过活体标本的颜色，特别是存在一个单一的、明显的白点，它的直径与眼眶大致相同，位于背鳍后基部与尾柄相交的地方。在现有的DNA条形码(线粒体COI基因)中，最相似的是来自日本的Chromis tingting(未校正差异为3.5%);然而，新物种C. mamatapara在表面上也与其他无法比较序列的物种相似，包括来自日本的C. okamurai和来自夏威夷的C. struhsakeri。由于Rapa Nui地区高度地理隔离，因此具有高度地方性，我们认为C. mamatapara是Rapa Nui, Isla Salas y Gómez和附近海山的中游生态系统特有的新物种，这一发现有助于该地区的高地方性，因此需要采取保护措施。
{"title":"A New Species of Chromis (Teleostei: Pomacentridae) from Mesophotic Coral Ecosystems of Rapa Nui (Easter Island) and Salas y Gómez, Chile","authors":"B. Shepherd, H. Pinheiro, Tyler A. Y. Phelps, Erin E. Easton, A. Pérez‐Matus, L. Rocha","doi":"10.1643/CI-19-294","DOIUrl":"https://doi.org/10.1643/CI-19-294","url":null,"abstract":"A new species of Chromis (Teleostei: Pomacentridae) is described from three specimens collected at 90 m depth in a mesophotic coral ecosystem at Rapa Nui, Chile. Chromis mamatapara, new species, can be distinguished from its congeners by the following combination of characters: dorsal-fin rays XIV,13–14; pectoral-fin rays 18–19, third from top of fin longest; tubed lateral-line scales 18; total gill rakers on first arch 30–32; vertebrae 11+15; and by coloration of living specimens, especially the presence of a single, pronounced, white spot, roughly the same diameter as the orbit, located where the posterior base of the dorsal fin intersects the caudal peduncle. The most similar DNA barcode (mitochondrial COI gene), among those available, is Chromis tingting from Japan (3.5% uncorrected divergence); however, C. mamatapara, new species, also superficially resembles other species for which sequences are unavailable for comparisons, including C. okamurai from Japan and C. struhsakeri from Hawaii. Due to the high geographic isolation and consequently high endemism in the Rapa Nui region, we believe that C. mamatapara, new species, is endemic to mesophotic ecosystems of Rapa Nui, Isla Salas y Gómez, and nearby seamounts, a discovery that contributes to the high endemism of the region and thus the need for conservation efforts.","PeriodicalId":10701,"journal":{"name":"Copeia","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2020-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44178726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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