Competition for resources between sympatric species can result in reduced fitness. Resource partitioning allows the minimization of competitive pressures, consequently promoting the coexistence of a diversity of species. We tested the hypothesis that the Striped Plateau Lizard (Sceloporus virgatus) and the Ornate Tree Lizard (Urosaurus ornatus) that occur in sympatry in the Chiricahua mountains of Arizona, USA have distinct ecological niches to minimize interspecific competition. We compared the activity times, perch microhabitat characteristics, and diet of these insectivorous lizards to test the prediction that they partition resources. Although we found no difference between the two species in the time at which lizards become active in the morning nor in the composition of their diets, the two species used different structural perch microhabitats. The Ornate Tree Lizard selected higher and narrower perches with more closed canopy than the Striped Plateau Lizard, and males generally occupied higher perches than females. These differences in perch microhabitat use may reduce interspecific competition and allow these two sympatric species to cohabitate.
{"title":"Niche Partitioning between Two Sympatric Lizards in the Chiricahua Mountains of Arizona","authors":"Rachel Bergeron, G. Blouin‐Demers","doi":"10.1643/CH-19-268","DOIUrl":"https://doi.org/10.1643/CH-19-268","url":null,"abstract":"Competition for resources between sympatric species can result in reduced fitness. Resource partitioning allows the minimization of competitive pressures, consequently promoting the coexistence of a diversity of species. We tested the hypothesis that the Striped Plateau Lizard (Sceloporus virgatus) and the Ornate Tree Lizard (Urosaurus ornatus) that occur in sympatry in the Chiricahua mountains of Arizona, USA have distinct ecological niches to minimize interspecific competition. We compared the activity times, perch microhabitat characteristics, and diet of these insectivorous lizards to test the prediction that they partition resources. Although we found no difference between the two species in the time at which lizards become active in the morning nor in the composition of their diets, the two species used different structural perch microhabitats. The Ornate Tree Lizard selected higher and narrower perches with more closed canopy than the Striped Plateau Lizard, and males generally occupied higher perches than females. These differences in perch microhabitat use may reduce interspecific competition and allow these two sympatric species to cohabitate.","PeriodicalId":10701,"journal":{"name":"Copeia","volume":"108 1","pages":"570 - 577"},"PeriodicalIF":2.6,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43618364","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}
Surfperches (Embiotocidae) are a unique family of viviparous fishes that have internal fertilization, gestation to the sub-adult stage, and live-birth; therefore, maternal investment is extremely high. This invokes the expectation that brood size is limited and females should be choosy and select few mates. Yet multiple paternity occurs in all eight species examined to date, with high prevalence ranging from 92–100%. Most surfperches are found along the Eastern Pacific coast, but Ditrema temminckii is distributed in the Western Pacific and we found differences in their mating strategy compared to other surfperches. In D. temminckii, prevalence of multiple paternity was only 60%. Further, the average number of sires was only 1.86 per brood even though brood sizes ranged from 12–45, and paternity was skewed, with the majority of paternity allocated to a single male. We propose that these differences may be associated with strong female selection on males in this species. Finally, we evaluated whether the number of fathers is an accurate estimate for the number of mates by comparing the number of alleles detected from fathers within the brood to the number of alleles from mates via genotyping alleles from spermatozoa within the uterine sac and found no significant difference, suggesting that the number of sires is a reasonable estimate for the number of mates in D. temminckii.
{"title":"Evaluating Reproductive Strategies and Female Bateman Gradients in Ditrema temminckii: Is the Number of Fathers a Good Approximation for the Number of Mates?","authors":"M. Izumiyama, S. Awata, K. Crow","doi":"10.1643/CE-19-271","DOIUrl":"https://doi.org/10.1643/CE-19-271","url":null,"abstract":"Surfperches (Embiotocidae) are a unique family of viviparous fishes that have internal fertilization, gestation to the sub-adult stage, and live-birth; therefore, maternal investment is extremely high. This invokes the expectation that brood size is limited and females should be choosy and select few mates. Yet multiple paternity occurs in all eight species examined to date, with high prevalence ranging from 92–100%. Most surfperches are found along the Eastern Pacific coast, but Ditrema temminckii is distributed in the Western Pacific and we found differences in their mating strategy compared to other surfperches. In D. temminckii, prevalence of multiple paternity was only 60%. Further, the average number of sires was only 1.86 per brood even though brood sizes ranged from 12–45, and paternity was skewed, with the majority of paternity allocated to a single male. We propose that these differences may be associated with strong female selection on males in this species. Finally, we evaluated whether the number of fathers is an accurate estimate for the number of mates by comparing the number of alleles detected from fathers within the brood to the number of alleles from mates via genotyping alleles from spermatozoa within the uterine sac and found no significant difference, suggesting that the number of sires is a reasonable estimate for the number of mates in D. temminckii.","PeriodicalId":10701,"journal":{"name":"Copeia","volume":"108 1","pages":"532 - 537"},"PeriodicalIF":2.6,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46108429","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}
Cecilia S. Blengini, Guadalupe López Juri, M. Chiaraviglio, D. Uñates, S. Naretto
Reproductive physiology is influenced by environmental pressures, particularly in ectothermic species living in harsh climatic conditions. Studying the period of time in which males exhibit semen availability and their sperm traits constitutes a powerful tool to evaluate the fertility potential of males because sperm size and sperm velocity have been proposed as determinants in fertilization success. Pristidactylus achalensis is a lizard endemic to the highest mountain areas in Central Argentina and shows a pattern of seasonal activity. Here, we study the period of time when males possess sperm during the active season and characterize the spermatozoa based on sperm morphometric and dynamic traits among males and within ejaculate. Males possess sperm in their ejaculates only during the spring months of the active season, suggesting that reproductive activity is restricted to this time. Spermatozoa of Pristidactylus achalensis show intra-specific variation in sperm traits among males and within ejaculate, suggesting different reproductive potential among males. Since this species only occupies the highest areas of the mountains and is categorized as vulnerable, basic information about reproduction and sperm physiology could be useful for potential population conservation strategies.
{"title":"Sperm Parameters in Pristidactylus achalensis (Squamata: Leiosauridae), a Lizard Endemic to the Highest Mountain Areas in Central Argentina","authors":"Cecilia S. Blengini, Guadalupe López Juri, M. Chiaraviglio, D. Uñates, S. Naretto","doi":"10.1643/CH-19-310","DOIUrl":"https://doi.org/10.1643/CH-19-310","url":null,"abstract":"Reproductive physiology is influenced by environmental pressures, particularly in ectothermic species living in harsh climatic conditions. Studying the period of time in which males exhibit semen availability and their sperm traits constitutes a powerful tool to evaluate the fertility potential of males because sperm size and sperm velocity have been proposed as determinants in fertilization success. Pristidactylus achalensis is a lizard endemic to the highest mountain areas in Central Argentina and shows a pattern of seasonal activity. Here, we study the period of time when males possess sperm during the active season and characterize the spermatozoa based on sperm morphometric and dynamic traits among males and within ejaculate. Males possess sperm in their ejaculates only during the spring months of the active season, suggesting that reproductive activity is restricted to this time. Spermatozoa of Pristidactylus achalensis show intra-specific variation in sperm traits among males and within ejaculate, suggesting different reproductive potential among males. Since this species only occupies the highest areas of the mountains and is categorized as vulnerable, basic information about reproduction and sperm physiology could be useful for potential population conservation strategies.","PeriodicalId":10701,"journal":{"name":"Copeia","volume":"108 1","pages":"538 - 544"},"PeriodicalIF":2.6,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48175233","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}
T HE ichthyologist, coauthor of the Fishes of Oklahoma book, naturalist painter, and long-time professor of zoology at Oklahoma State University, RUDOLPH JOHN MILLER, affectionately known as ‘‘Rudy’’ to his friends, passed away in Stillwater, Oklahoma on 10 December 2017 at the age of 83. He was born in Gbely, Czechoslovakia (now Slovakia) on 25 September 1934. Rudy is survived by his three children and their spouses and grandchildren. His obituary in the Stillwater, Oklahoma newspaper noted that Rudy was a good husband, father, and provider, a man of great talent and intelligence with a wonderful sense of humor. Rudolph J. Miller came to America with his mother, Josephine Brunofski, wife of James Miller, as a young child and grew up in and around Rochester, New York. Although conceived in America, the tradition in Rudy’s family was that his pregnant mother return to ‘‘the old country’’ to have her child. As a young boy Rudy learned to love the outdoors from going fishing with his brother and he learned to draw and paint the wildlife of the area. He studied the area wildlife near his home and loved to watch the birds on Lake Ontario. He later entered Cornell University and graduated in 1956 with his bachelor’s degree in Conservation. While at Cornell, Rudy was closely associated with like-minded classmates and future luminaries who loved natural history including Bruce Collette, Tom Poulson, Tom Frazetta, and Fred Gehlbach as well as his own brother, Bob (‘‘R.V.’’ Miller), in the Department of Conservation in Fernow Hall. R.V. went on to become a well-known marine mammal scientist for NOAA in Seattle. C. Richard Robins, himself later a world-famous ichthyologist, was one of their lab instructors in vertebrate zoology as was Helen (Rudy’s future wife) in Botany. ‘‘Helen was a delightful vision in our Botany labs and it always amazed me that Rudy persuaded Helen to marry him!’’ (Bruce Collette, pers. comm.). After marrying Helen in 1957, the new couple moved to Tulane University where Rudy studied under the legendary Royal D. Suttkus. Rudy’s master’s thesis was ‘‘A Review of the Seabasses of the Genus Centropristis,’’ which he later published in Tulane Studies in Botany and Zoology (Miller, 1959). Rudy loved to tell about Suttkus rousting out him and other students in the middle of the night in the midst of a tropical downpour to go collect fishes in cottonmouth and alligator laden habitats. Under Sut’s tutelage, Rudy learned the wonderful fish fauna of the southeastern United States. After receiving his master’s degree in 1958, Rudy and Helen returned to Cornell where they each earned a Ph.D. Rudy studied under another fish legend, Edward C. Raney, switching to study fish behavior for his dissertation. His dissertation and subsequent publication on ‘‘Behavior and Fig. 1. Rudy Miller in 1971 examining specimens of Eupomacentrus jenkinsi (now Stegastes marginatus), a species of small damselfish. Rudy made behavioral observations on this species whil
{"title":"Rudolph J. Miller (1934–2017): Oklahoma Ichthyologist, Teacher and Mentor, and Naturalist Painter","authors":"H. Robison","doi":"10.1643/ct2020107","DOIUrl":"https://doi.org/10.1643/ct2020107","url":null,"abstract":"T HE ichthyologist, coauthor of the Fishes of Oklahoma book, naturalist painter, and long-time professor of zoology at Oklahoma State University, RUDOLPH JOHN MILLER, affectionately known as ‘‘Rudy’’ to his friends, passed away in Stillwater, Oklahoma on 10 December 2017 at the age of 83. He was born in Gbely, Czechoslovakia (now Slovakia) on 25 September 1934. Rudy is survived by his three children and their spouses and grandchildren. His obituary in the Stillwater, Oklahoma newspaper noted that Rudy was a good husband, father, and provider, a man of great talent and intelligence with a wonderful sense of humor. Rudolph J. Miller came to America with his mother, Josephine Brunofski, wife of James Miller, as a young child and grew up in and around Rochester, New York. Although conceived in America, the tradition in Rudy’s family was that his pregnant mother return to ‘‘the old country’’ to have her child. As a young boy Rudy learned to love the outdoors from going fishing with his brother and he learned to draw and paint the wildlife of the area. He studied the area wildlife near his home and loved to watch the birds on Lake Ontario. He later entered Cornell University and graduated in 1956 with his bachelor’s degree in Conservation. While at Cornell, Rudy was closely associated with like-minded classmates and future luminaries who loved natural history including Bruce Collette, Tom Poulson, Tom Frazetta, and Fred Gehlbach as well as his own brother, Bob (‘‘R.V.’’ Miller), in the Department of Conservation in Fernow Hall. R.V. went on to become a well-known marine mammal scientist for NOAA in Seattle. C. Richard Robins, himself later a world-famous ichthyologist, was one of their lab instructors in vertebrate zoology as was Helen (Rudy’s future wife) in Botany. ‘‘Helen was a delightful vision in our Botany labs and it always amazed me that Rudy persuaded Helen to marry him!’’ (Bruce Collette, pers. comm.). After marrying Helen in 1957, the new couple moved to Tulane University where Rudy studied under the legendary Royal D. Suttkus. Rudy’s master’s thesis was ‘‘A Review of the Seabasses of the Genus Centropristis,’’ which he later published in Tulane Studies in Botany and Zoology (Miller, 1959). Rudy loved to tell about Suttkus rousting out him and other students in the middle of the night in the midst of a tropical downpour to go collect fishes in cottonmouth and alligator laden habitats. Under Sut’s tutelage, Rudy learned the wonderful fish fauna of the southeastern United States. After receiving his master’s degree in 1958, Rudy and Helen returned to Cornell where they each earned a Ph.D. Rudy studied under another fish legend, Edward C. Raney, switching to study fish behavior for his dissertation. His dissertation and subsequent publication on ‘‘Behavior and Fig. 1. Rudy Miller in 1971 examining specimens of Eupomacentrus jenkinsi (now Stegastes marginatus), a species of small damselfish. Rudy made behavioral observations on this species whil","PeriodicalId":10701,"journal":{"name":"Copeia","volume":"108 1","pages":"692 - 697"},"PeriodicalIF":2.6,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48285373","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 viviparous halfbeak, Nomorhamphus aenigma, new species, from the upper stream of the Cerekang River in central Sulawesi, Indonesia is described. The new species is distinguished from all other zenarchopterids by the complete absence of elongate lower jaws. Although secondary loss of elongate jaws is also known from several hemiramphids, N. aenigma, new species, is clearly different from them by having no elongate jaws throughout ontogeny.
{"title":"A New “Beakless” Halfbeak of the Genus Nomorhamphus from Sulawesi (Teleostei: Zenarchopteridae)","authors":"Hirozumi Kobayashi, K. Masengi, K. Yamahira","doi":"10.1643/CI-19-313","DOIUrl":"https://doi.org/10.1643/CI-19-313","url":null,"abstract":"A new viviparous halfbeak, Nomorhamphus aenigma, new species, from the upper stream of the Cerekang River in central Sulawesi, Indonesia is described. The new species is distinguished from all other zenarchopterids by the complete absence of elongate lower jaws. Although secondary loss of elongate jaws is also known from several hemiramphids, N. aenigma, new species, is clearly different from them by having no elongate jaws throughout ontogeny.","PeriodicalId":10701,"journal":{"name":"Copeia","volume":"108 1","pages":"522 - 531"},"PeriodicalIF":2.6,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49498568","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}
Zachary T. Wood, Isaac D. Shepard, Stephen T. Hurley, Mitchell R. Paisker, V. R. Hensley, M. Kinnison
Many invasive species may be constrained in their ability to invade high latitude or elevation habitats due to limits of cold tolerance. However, isolated populations at the edge of these species' geographic ranges may face a combination of strong selection and lack of maladaptive gene flow that allows them to adapt to the cold and invade further. Here we show that an isolated population of Gambusia affinis (on Cape Cod, MA, USA), one of the most invasive fish in the world, can survive temperatures lower than any reported tolerances for other populations, with large, long-lived females showing more tolerance than males. Indeed, male acute cold tolerance appears insufficient, suggesting the population may persist through winters mainly via the ability of mated females to delay offspring production until spring. This combination of female cold tolerance and life history may open the door for further expansion of this invasive species into high latitude freshwater habitats.
{"title":"Sex-Dependent Cold Tolerance at the Northern Invasive Range Limit of Gambusia affinis on Cape Cod, Massachusetts","authors":"Zachary T. Wood, Isaac D. Shepard, Stephen T. Hurley, Mitchell R. Paisker, V. R. Hensley, M. Kinnison","doi":"10.1643/CE-19-332","DOIUrl":"https://doi.org/10.1643/CE-19-332","url":null,"abstract":"Many invasive species may be constrained in their ability to invade high latitude or elevation habitats due to limits of cold tolerance. However, isolated populations at the edge of these species' geographic ranges may face a combination of strong selection and lack of maladaptive gene flow that allows them to adapt to the cold and invade further. Here we show that an isolated population of Gambusia affinis (on Cape Cod, MA, USA), one of the most invasive fish in the world, can survive temperatures lower than any reported tolerances for other populations, with large, long-lived females showing more tolerance than males. Indeed, male acute cold tolerance appears insufficient, suggesting the population may persist through winters mainly via the ability of mated females to delay offspring production until spring. This combination of female cold tolerance and life history may open the door for further expansion of this invasive species into high latitude freshwater habitats.","PeriodicalId":10701,"journal":{"name":"Copeia","volume":"108 1","pages":"670 - 678"},"PeriodicalIF":2.6,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44543634","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}
The Southeast Asian cyprinid genus Henicorhynchus has a complicated taxonomic history due to morphological similarities with other genera and among species within the genus itself. Henicorhynchus and its constituent species are herein revised based on morphological examinations of over 1,000 specimens with a particular emphasis on oromandibular structures. Five species are now recognized in the genus. Henicorhynchus entmema and H. caudimaculatus are senior synonyms of H. lobatus and H. lineatus, respectively. Henicorhynchus caudiguttatus is removed from synonymy with H. caudimaculatus. A revised diagnosis of the South Asian cyprinid genus Gymnostomus, previously considered a senior synonym of Henicorhynchus, is also provided.
{"title":"Revision of the Genus Henicorhynchus, with a Revised Diagnosis of Gymnostomus (Cyprinidae: Labeoninae)","authors":"P. Ciccotto, L. Page","doi":"10.1643/CI-19-304","DOIUrl":"https://doi.org/10.1643/CI-19-304","url":null,"abstract":"The Southeast Asian cyprinid genus Henicorhynchus has a complicated taxonomic history due to morphological similarities with other genera and among species within the genus itself. Henicorhynchus and its constituent species are herein revised based on morphological examinations of over 1,000 specimens with a particular emphasis on oromandibular structures. Five species are now recognized in the genus. Henicorhynchus entmema and H. caudimaculatus are senior synonyms of H. lobatus and H. lineatus, respectively. Henicorhynchus caudiguttatus is removed from synonymy with H. caudimaculatus. A revised diagnosis of the South Asian cyprinid genus Gymnostomus, previously considered a senior synonym of Henicorhynchus, is also provided.","PeriodicalId":10701,"journal":{"name":"Copeia","volume":"108 1","pages":"485 - 502"},"PeriodicalIF":2.6,"publicationDate":"2020-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44397909","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}
Gymnotus is the most species-rich and geographically widespread genus of gymnotiform electric fishes and has been widely explored to understand mechanisms of diversification in Neotropical freshwater fishes at a continental scale. Within Gymnotus, the subgenus Lamontianus is a phenotypically distinctive clade with an elongate, cylindrical body shape currently known from four valid species (G. anguillaris, G. cataniapo, G. pedanopterus, and G. tiquie) restricted to rivers draining the Guiana Shield. Here we use aspects of body-surface coloration, meristic, morphological, and osteological data, including cranial, laterosensory pore, and postcranial characters, to diagnose two new species of Lamontianus that inhabit the Aripuanã and Arapiuns rivers that drain the Brazilian Shield. We also use geometric morphometric analyses of head shape to separate the new species from one another and other species of Lamontianus. We report biogeographic distributions for all species of Lamontianus and estimate ancestral geographic ranges and range evolution using the parametric biogeographic program BioGeoBEARS. We use the phylogeny of Lamontianus to test alternative hypotheses regarding lineage divergence times, before or after the formation of the modern East-draining Amazon at c. 10 Ma. Our analysis suggests that diversification in Lamontianus occurred primarily by geographic range fragmentation (vicariance) from an ancestral species distributed across the Western Guiana Shield. These results are similar to those of other Gymnotus and gymnotiform clades, where allopatric speciation and secondary contact due to geographic range expansion are commonly observed. This study brings to 46 the number of valid species of the genus Gymnotus, and to six the number of valid species of the subgenus Lamontianus.
裸子鱼属(Gymnotus)是裸子形电鱼中种类最丰富、分布最广的属，在了解大陆尺度新热带淡水鱼的多样化机制方面得到了广泛的探索。在Gymnotus中，Lamontianus亚属是一个具有显着特征的分支，具有细长的圆柱形身体形状，目前已知的四个有效物种(G. anguillaris, G. cataniapo, G. pedanopterus和G. tiquie)仅限于排出圭亚那盾的河流。在这里，我们使用体表颜色、分生、形态学和骨学数据，包括颅、侧感觉孔和颅后特征，来诊断两个新的Lamontianus物种，它们生活在巴西盾河的Aripuanã和Arapiuns河中。我们还利用头部形状的几何形态分析来区分新种和其他种。利用参数化生物地理程序biogeoars，我们报告了所有拉蒙提亚属物种的生物地理分布，并估计了其祖先的地理范围和范围演变。我们使用Lamontianus的系统发育来测试关于谱系分化时间的替代假设，在现代东部亚马逊河形成之前或之后，大约10 Ma。我们的分析表明，Lamontianus的多样化主要是由分布在西圭亚那地盾的祖先物种的地理范围碎片化(vicariance)发生的。这些结果与其他裸子目和裸子形分支相似，在这些分支中，通常观察到异域物种形成和由于地理范围扩大而产生的二次接触。至此，Gymnotus属的有效种数已达46种，Lamontianus亚属的有效种数已达6种。
{"title":"Two New Species of Gymnotus (Gymnotiformes: Gymnotidae) from Brazil and Historical Biogeography of the Subgenus Lamontianus","authors":"L. Y. Kim, W. Crampton, J. Albert","doi":"10.1643/CI-19-205","DOIUrl":"https://doi.org/10.1643/CI-19-205","url":null,"abstract":"Gymnotus is the most species-rich and geographically widespread genus of gymnotiform electric fishes and has been widely explored to understand mechanisms of diversification in Neotropical freshwater fishes at a continental scale. Within Gymnotus, the subgenus Lamontianus is a phenotypically distinctive clade with an elongate, cylindrical body shape currently known from four valid species (G. anguillaris, G. cataniapo, G. pedanopterus, and G. tiquie) restricted to rivers draining the Guiana Shield. Here we use aspects of body-surface coloration, meristic, morphological, and osteological data, including cranial, laterosensory pore, and postcranial characters, to diagnose two new species of Lamontianus that inhabit the Aripuanã and Arapiuns rivers that drain the Brazilian Shield. We also use geometric morphometric analyses of head shape to separate the new species from one another and other species of Lamontianus. We report biogeographic distributions for all species of Lamontianus and estimate ancestral geographic ranges and range evolution using the parametric biogeographic program BioGeoBEARS. We use the phylogeny of Lamontianus to test alternative hypotheses regarding lineage divergence times, before or after the formation of the modern East-draining Amazon at c. 10 Ma. Our analysis suggests that diversification in Lamontianus occurred primarily by geographic range fragmentation (vicariance) from an ancestral species distributed across the Western Guiana Shield. These results are similar to those of other Gymnotus and gymnotiform clades, where allopatric speciation and secondary contact due to geographic range expansion are commonly observed. This study brings to 46 the number of valid species of the genus Gymnotus, and to six the number of valid species of the subgenus Lamontianus.","PeriodicalId":10701,"journal":{"name":"Copeia","volume":"108 1","pages":"468 - 484"},"PeriodicalIF":2.6,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67412534","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}
Trichomycterus lauzannii, new species, is described from the upper Río Beni basin in La Paz, Bolivia. The new species is distinguished from congeners by the posterior cranial fontanel reduced to a small round opening on the posterior portion of supraoccipital bone and the possession of a rounded anterior cranial fontanel between frontal bones. In addition, the new species can be further distinguished from congeners by the possession of seven or fewer odontodes in the opercular patch, a pelvic fin which does not reach the anus when depressed, round blotches along the side of body, a first pectoral-fin ray prolonged as a short distal filament, and several meristic and morphometric features. Comparisons are given with similar congeners (T. cachiraensis, T. megantoni, T. sketi, and T. steindachneri).
{"title":"A New Species of Trichomycterus (Siluriformes: Trichomycteridae) from Madidi National Park, Amazon Basin, Bolivia","authors":"G. Miranda, L. Fernandez","doi":"10.1643/CI-19-291","DOIUrl":"https://doi.org/10.1643/CI-19-291","url":null,"abstract":"Trichomycterus lauzannii, new species, is described from the upper Río Beni basin in La Paz, Bolivia. The new species is distinguished from congeners by the posterior cranial fontanel reduced to a small round opening on the posterior portion of supraoccipital bone and the possession of a rounded anterior cranial fontanel between frontal bones. In addition, the new species can be further distinguished from congeners by the possession of seven or fewer odontodes in the opercular patch, a pelvic fin which does not reach the anus when depressed, round blotches along the side of body, a first pectoral-fin ray prolonged as a short distal filament, and several meristic and morphometric features. Comparisons are given with similar congeners (T. cachiraensis, T. megantoni, T. sketi, and T. steindachneri).","PeriodicalId":10701,"journal":{"name":"Copeia","volume":"108 1","pages":"459 - 467"},"PeriodicalIF":2.6,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48009668","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}
All organisms are constrained by limited energy and thus must allocate resources in such a way to maximize fitness. Due to their importance to survival, immunity and performance are each often favored in selective environments and thus may be tradeoffs of each other. To test this tradeoff hypothesis, we compared performance to three constitutive measures of immunity in a wild hybrid population of water snakes (Nerodia clarkii X Nerodia fasciata): agglutination response to sheep red blood cells (SRBC), heterophil: lymphocyte ratio (HLR), and bactericidal ability (BA). Performance was quantified by exercising snakes up to the point of loss of righting response (LRR) and measuring plasma lactate concentration at this point of fatigue. Support for the tradeoff hypothesis was mixed among the immune assays. Bactericidal ability had a significant positive correlation with LRR (P = 0.003, R2 = 0.263); this was counter to our tradeoff hypothesis and suggests that individuals invest in both traits simultaneously. We failed to detect a significant relationship between SRBC and performance. A significant negative relationship was found between HLR and LRR (P = 0.005, R2 = 0.237). Heterophil: lymphocyte ratio is a balance between innate and acquired immunity that is also indicative of baseline stress. This result showed that snakes with higher HLR are constrained and perform poorly compared to snakes with lower HLR, thus indicating a potential role of stress in affecting performance. Alternatively, this result may denote that internal tradeoffs in the immune system between innate and acquired immunity drive tradeoffs between immunity and performance. Snout–vent length (SVL) was significantly positively correlated with our performance measure (P = 0.012, R2 = 0.192). This result may be explained by selection driving increases in performance and/or ontogenetic development of the locomotor apparatus. Similarly, SVL was an important driver of immunity in snakes. Together, these results clearly show an important link exists between multiple physiological traits that are each vital to survival.
所有生物体都受到有限能量的限制，因此必须以这种方式分配资源，以最大限度地提高适应性。由于它们对生存的重要性，免疫力和性能在选择性环境中通常都很受欢迎，因此可能是相互权衡的结果。为了验证这一折衷假设，我们将其性能与水生蛇野生杂交种群（克氏Nerodia clarkii X Nerodia fasciata）的三种组成性免疫指标进行了比较：对绵羊红细胞的凝集反应（SRBC）、嗜异性淋巴细胞比（HLR）和杀菌能力（BA）。通过锻炼蛇直到失去扶正反应（LRR）并测量疲劳时的血浆乳酸浓度来量化表现。在免疫测定中，对折衷假设的支持是混合的。杀菌能力与LRR呈正相关（P=0.003，R2=0.263）；这与我们的权衡假设相反，并表明个人同时投资于这两种特质。我们未能发现SRBC与性能之间存在显著关系。HLR和LRR之间存在显著的负相关（P=0.005，R2=0.237）。嗜异性：淋巴细胞比率是先天免疫和后天免疫之间的平衡，也是基线应激的指标。这一结果表明，与HLR较低的蛇相比，HLR较高的蛇受到约束，表现不佳，因此表明应激在影响表现方面的潜在作用。或者，这一结果可能表明，免疫系统中先天免疫和后天免疫之间的内部权衡驱动了免疫和性能之间的权衡。Snout–vent长度（SVL）与我们的性能指标显著正相关（P=0.012，R2=0.192）。这一结果可以通过选择驱动性能的提高和/或运动装置的个体发育来解释。同样，SVL也是蛇免疫的重要驱动因素。总之，这些结果清楚地表明，对生存至关重要的多种生理特征之间存在着重要联系。
{"title":"A Test of Tradeoffs between Performance and Immunity in Water Snakes (Nerodia clarkii X Nerodia fasciata)","authors":"W. H. Hawthorne, J. Goessling","doi":"10.1643/CP-19-281","DOIUrl":"https://doi.org/10.1643/CP-19-281","url":null,"abstract":"All organisms are constrained by limited energy and thus must allocate resources in such a way to maximize fitness. Due to their importance to survival, immunity and performance are each often favored in selective environments and thus may be tradeoffs of each other. To test this tradeoff hypothesis, we compared performance to three constitutive measures of immunity in a wild hybrid population of water snakes (Nerodia clarkii X Nerodia fasciata): agglutination response to sheep red blood cells (SRBC), heterophil: lymphocyte ratio (HLR), and bactericidal ability (BA). Performance was quantified by exercising snakes up to the point of loss of righting response (LRR) and measuring plasma lactate concentration at this point of fatigue. Support for the tradeoff hypothesis was mixed among the immune assays. Bactericidal ability had a significant positive correlation with LRR (P = 0.003, R2 = 0.263); this was counter to our tradeoff hypothesis and suggests that individuals invest in both traits simultaneously. We failed to detect a significant relationship between SRBC and performance. A significant negative relationship was found between HLR and LRR (P = 0.005, R2 = 0.237). Heterophil: lymphocyte ratio is a balance between innate and acquired immunity that is also indicative of baseline stress. This result showed that snakes with higher HLR are constrained and perform poorly compared to snakes with lower HLR, thus indicating a potential role of stress in affecting performance. Alternatively, this result may denote that internal tradeoffs in the immune system between innate and acquired immunity drive tradeoffs between immunity and performance. Snout–vent length (SVL) was significantly positively correlated with our performance measure (P = 0.012, R2 = 0.192). This result may be explained by selection driving increases in performance and/or ontogenetic development of the locomotor apparatus. Similarly, SVL was an important driver of immunity in snakes. Together, these results clearly show an important link exists between multiple physiological traits that are each vital to survival.","PeriodicalId":10701,"journal":{"name":"Copeia","volume":"108 1","pages":"453 - 458"},"PeriodicalIF":2.6,"publicationDate":"2020-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41887433","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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