Lauren Diaz, S. Unger, Lori Williams, Catherine M. Bodinof Jachowski
The Hellbender (Cryptobranchus alleganiensis) is a giant salamander inhabiting streams in the eastern United States that has experienced range-wide declines. It is estimated that Hellbenders have declined by 70% in some portions of their range, and many populations are composed solely of older adults, suggesting that a lack of successful breeding or low larval survival may be driving some declines. Although successful reproduction and larval survival influence the long-term stability of Hellbender populations, little is known about the ecological requirements of immature age classes. Understanding the requirements of immature Hellbenders is essential for accurately gauging population health and designing long-term conservation efforts. The objective of our study is to investigate associations between immature Hellbender habitat use and abiotic factors hypothesized to influence survival. We quantified habitat selection of immature Hellbenders within a use/availability framework in six streams in North Carolina known to contain all Hellbender age classes. Our results suggest that immature Hellbenders select home ranges based on a reduced water velocity and the presence of unembedded cobble beds and, within that home range, select unembedded mid-sized cover (18–28 cm) as microhabitat. We recommend targeting immature age classes during monitoring surveys to ensure a complete understanding of a population's status. This can be accomplished by conducting targeted surveys in areas of the stream with a slower current and beds of heterogeneous, unembedded cobble. We also recommend considering habitat preferences of immature age classes when selecting sites for Hellbender reintroductions and designing stream restoration initiatives to benefit Hellbender populations.
{"title":"Resource Selection Patterns of Immature Eastern Hellbenders in North Carolina, USA","authors":"Lauren Diaz, S. Unger, Lori Williams, Catherine M. Bodinof Jachowski","doi":"10.1643/h2020050","DOIUrl":"https://doi.org/10.1643/h2020050","url":null,"abstract":"The Hellbender (Cryptobranchus alleganiensis) is a giant salamander inhabiting streams in the eastern United States that has experienced range-wide declines. It is estimated that Hellbenders have declined by 70% in some portions of their range, and many populations are composed solely of older adults, suggesting that a lack of successful breeding or low larval survival may be driving some declines. Although successful reproduction and larval survival influence the long-term stability of Hellbender populations, little is known about the ecological requirements of immature age classes. Understanding the requirements of immature Hellbenders is essential for accurately gauging population health and designing long-term conservation efforts. The objective of our study is to investigate associations between immature Hellbender habitat use and abiotic factors hypothesized to influence survival. We quantified habitat selection of immature Hellbenders within a use/availability framework in six streams in North Carolina known to contain all Hellbender age classes. Our results suggest that immature Hellbenders select home ranges based on a reduced water velocity and the presence of unembedded cobble beds and, within that home range, select unembedded mid-sized cover (18–28 cm) as microhabitat. We recommend targeting immature age classes during monitoring surveys to ensure a complete understanding of a population's status. This can be accomplished by conducting targeted surveys in areas of the stream with a slower current and beds of heterogeneous, unembedded cobble. We also recommend considering habitat preferences of immature age classes when selecting sites for Hellbender reintroductions and designing stream restoration initiatives to benefit Hellbender populations.","PeriodicalId":29892,"journal":{"name":"Ichthyology and Herpetology","volume":"110 1","pages":"398 - 408"},"PeriodicalIF":1.5,"publicationDate":"2022-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42300163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Canales-Gordillo, H. A. Pérez-Mendoza, M. A. Domínguez-Godoy, V. Argáez, Israel Solano-Zavaleta, A. H. Díaz de la Vega-Pérez, J. Zúñiga‐Vega
Demographic models are useful for analyzing the effect of selective pressures on populations. Polymorphic populations display dramatic variation in phenotype, and different morphotypes representing alternative strategies are characterized by specific sets of behavioral, physiological, and morphological traits. Coloration is a classic polymorphic trait, and variation in this trait has been linked to other traits, such as aggressiveness, size, and immune responses. Many studies of polymorphic populations have placed individuals into discrete categories, assuming that all individuals of each morphotype have the same performance; however, traits related to color can vary between individuals possessing the same coloration or classified as the same morphotype. Here, we determined the association of survival to a continuous or a discrete classification based on the percentage of colored area in the gular spots in four populations of the Mesquite Lizard Sceloporus grammicus and tested for patterns among populations. In two of our study sites (both located in the volcano “La Malinche”), there was no association of coloration on survival with either a discrete or continuous classification. At the other two study sites, there was a continuous association of color on survival, which suggests that previous studies of variation in polymorphic species might have often been conducted at an inappropriate “resolution” and that predictions in our analyses could be improved.
{"title":"Morphotypic Variation in Throat Coloration: A Continuous or a Discrete Trait? A Survival Analysis on a Polymorphic Lizard","authors":"B. Canales-Gordillo, H. A. Pérez-Mendoza, M. A. Domínguez-Godoy, V. Argáez, Israel Solano-Zavaleta, A. H. Díaz de la Vega-Pérez, J. Zúñiga‐Vega","doi":"10.1643/h2020158","DOIUrl":"https://doi.org/10.1643/h2020158","url":null,"abstract":"Demographic models are useful for analyzing the effect of selective pressures on populations. Polymorphic populations display dramatic variation in phenotype, and different morphotypes representing alternative strategies are characterized by specific sets of behavioral, physiological, and morphological traits. Coloration is a classic polymorphic trait, and variation in this trait has been linked to other traits, such as aggressiveness, size, and immune responses. Many studies of polymorphic populations have placed individuals into discrete categories, assuming that all individuals of each morphotype have the same performance; however, traits related to color can vary between individuals possessing the same coloration or classified as the same morphotype. Here, we determined the association of survival to a continuous or a discrete classification based on the percentage of colored area in the gular spots in four populations of the Mesquite Lizard Sceloporus grammicus and tested for patterns among populations. In two of our study sites (both located in the volcano “La Malinche”), there was no association of coloration on survival with either a discrete or continuous classification. At the other two study sites, there was a continuous association of color on survival, which suggests that previous studies of variation in polymorphic species might have often been conducted at an inappropriate “resolution” and that predictions in our analyses could be improved.","PeriodicalId":29892,"journal":{"name":"Ichthyology and Herpetology","volume":"110 1","pages":"388 - 397"},"PeriodicalIF":1.5,"publicationDate":"2022-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43755580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Blanding's Turtles (International Union for Conservation of Nature [IUCN] Endangered) are long-lived reptiles with delayed sexual maturity. Anthropogenic landscape changes have increased threats to juvenile turtles, resulting in unnaturally low recruitment. Head-starting has become a popular conservation strategy that aims to increase juvenile recruitment by avoiding the increased predation of the vulnerable nest and hatchling age class. However, there is still debate about whether or not it is an effective management tool. Assessments of head-starting are becoming more prevalent, but long-term studies are needed to critically evaluate the success of such interventions. In particular, information is needed on how head-starts fare compared to wild-hatched turtles. The Lake County Forest Preserve District (LCFPD) in northeastern Illinois initiated a long-term capture–mark–recapture project in 2004. As of 2018, 127 wild-hatched juvenile turtles had been captured (59 of which had been captured in multiple years) and 148 adult turtles had been captured (116 of which had been recaptured in multiple years). Since 2010, LCFPD has released 491 headstarted turtles during the year following hatching, 138 of which have been recaptured during successive years. We used von Bertalanffy growth analysis to compare growth trajectories and Cormack-Jolly-Seber modeling techniques to compare survival rates of wild-hatched and head-started turtles. At release, head-started turtles were about the size of two-year-old wild-hatched turtles and grew in parallel to their wild-hatched counterparts. The top-ranked survival models demonstrated that survival increased with age for both wild-hatched (71–98%) and head-started turtles (63–90%), with overlapping confidence intervals. These results suggest that head-started juveniles perform similarly to like-aged wild-hatched juveniles despite head-starts having attained greater body size. We estimated adult survival to be 95% with an environmental variance of 0.0011 and stable or positive population growth (k). Although the success of head-starting cannot be fully assessed until turtles are recruited into the adult population and successfully reproduce, patterns of head-start growth and survival provide positive intermediate measures of success. Our estimation of juvenile and adult survival, along with other demographic information from this population, will provide for more accurate population projections that will aid in evaluating conservation strategies for this population and potentially for Blanding's Turtles elsewhere.
{"title":"Growth and Survival of Wild and Head-Started Blanding's Turtles (Emydoidea blandingii)","authors":"Callie Klatt Golba, G. Glowacki, R. King","doi":"10.1643/h2021005","DOIUrl":"https://doi.org/10.1643/h2021005","url":null,"abstract":"Blanding's Turtles (International Union for Conservation of Nature [IUCN] Endangered) are long-lived reptiles with delayed sexual maturity. Anthropogenic landscape changes have increased threats to juvenile turtles, resulting in unnaturally low recruitment. Head-starting has become a popular conservation strategy that aims to increase juvenile recruitment by avoiding the increased predation of the vulnerable nest and hatchling age class. However, there is still debate about whether or not it is an effective management tool. Assessments of head-starting are becoming more prevalent, but long-term studies are needed to critically evaluate the success of such interventions. In particular, information is needed on how head-starts fare compared to wild-hatched turtles. The Lake County Forest Preserve District (LCFPD) in northeastern Illinois initiated a long-term capture–mark–recapture project in 2004. As of 2018, 127 wild-hatched juvenile turtles had been captured (59 of which had been captured in multiple years) and 148 adult turtles had been captured (116 of which had been recaptured in multiple years). Since 2010, LCFPD has released 491 headstarted turtles during the year following hatching, 138 of which have been recaptured during successive years. We used von Bertalanffy growth analysis to compare growth trajectories and Cormack-Jolly-Seber modeling techniques to compare survival rates of wild-hatched and head-started turtles. At release, head-started turtles were about the size of two-year-old wild-hatched turtles and grew in parallel to their wild-hatched counterparts. The top-ranked survival models demonstrated that survival increased with age for both wild-hatched (71–98%) and head-started turtles (63–90%), with overlapping confidence intervals. These results suggest that head-started juveniles perform similarly to like-aged wild-hatched juveniles despite head-starts having attained greater body size. We estimated adult survival to be 95% with an environmental variance of 0.0011 and stable or positive population growth (k). Although the success of head-starting cannot be fully assessed until turtles are recruited into the adult population and successfully reproduce, patterns of head-start growth and survival provide positive intermediate measures of success. Our estimation of juvenile and adult survival, along with other demographic information from this population, will provide for more accurate population projections that will aid in evaluating conservation strategies for this population and potentially for Blanding's Turtles elsewhere.","PeriodicalId":29892,"journal":{"name":"Ichthyology and Herpetology","volume":"110 1","pages":"378 - 387"},"PeriodicalIF":1.5,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44116177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. L. Casteel, Jennifer F. Moore, W. E. Pine, Gerald R. Johnston
A multitude of different statistical models are commonly used to monitor trends in wildlife populations. Most are used to estimate abundance or survival (or both), and these estimates are then examined over time to infer trends in a population. The choice of which model to use is influenced by the key research question of interest and the types of data available. The accuracy and precision of any estimate from a population model are determined by whether the data meet the model assumptions. We assessed the performance of both closed and open capture–recapture models for determining trends in abundance and survival of River Cooters, Pseudemys concinna, in the Santa Fe River, Florida from 2009–2019. We fit three closed models to estimate abundance, one open model to estimate survival, and two robust design models to estimate both abundance and survival. We then used simulation to generate three datasets that represented different sampling designs, including one that mimics our field data, to assess model performance and compare tradeoffs in sampling design. We recommend using the robust design framework when possible as this design and model estimation returned accurate and precise estimates of abundance and survival. This model estimated survival ranging from 0.69–0.95 and capture probability from 0.21–0.25. This design requires consistent sampling of at least three events per year during a closed period, repeated over at least five years, to estimate survival between years. In situations where samples could not be repeated across years, closed population models are likely the most reliable framework in terms of model precision and accuracy. Overall, sampling designs that allow for repeated sampling and align the biology of the study species and the assumptions of the statistical model are likely the most informative approaches for sampling River Cooters and similar species.
许多不同的统计模型通常用于监测野生动物种群的趋势。大多数用于估计丰度或存活率(或两者兼而有之)，然后随着时间的推移对这些估计进行检验，以推断种群的趋势。使用哪种模型的选择受到感兴趣的关键研究问题和可用数据类型的影响。人口模型估计的准确性和精密度取决于数据是否符合模型假设。我们评估了封闭和开放捕获-再捕获模型的性能，以确定2009-2019年佛罗里达州圣达菲河(Santa Fe River)库特河(River Cooters, Pseudemys concinna)的丰度和生存趋势。我们拟合了三个封闭模型来估计丰度，一个开放模型来估计生存，两个稳健设计模型来估计丰度和生存。然后，我们使用模拟来生成三个代表不同采样设计的数据集，其中一个模拟了我们的现场数据，以评估模型性能并比较采样设计中的权衡。我们建议尽可能使用稳健设计框架，因为这种设计和模型估计返回了丰度和存活率的准确估计。该模型估计存活率为0.69-0.95，捕获概率为0.21-0.25。该设计要求在封闭期间每年至少进行三次一致的采样，重复至少五年，以估计各年之间的生存率。在样本不能多年重复的情况下，就模型精度和准确性而言，封闭人口模型可能是最可靠的框架。总的来说，允许重复采样并将研究物种的生物学和统计模型的假设结合起来的采样设计可能是对库特河和类似物种进行采样的最有效的方法。
{"title":"Analysis of Methods to Estimate Abundance of River Cooters, Pseudemys concinna: An Example from the Santa Fe River, Florida","authors":"J. L. Casteel, Jennifer F. Moore, W. E. Pine, Gerald R. Johnston","doi":"10.1643/h2021048","DOIUrl":"https://doi.org/10.1643/h2021048","url":null,"abstract":"A multitude of different statistical models are commonly used to monitor trends in wildlife populations. Most are used to estimate abundance or survival (or both), and these estimates are then examined over time to infer trends in a population. The choice of which model to use is influenced by the key research question of interest and the types of data available. The accuracy and precision of any estimate from a population model are determined by whether the data meet the model assumptions. We assessed the performance of both closed and open capture–recapture models for determining trends in abundance and survival of River Cooters, Pseudemys concinna, in the Santa Fe River, Florida from 2009–2019. We fit three closed models to estimate abundance, one open model to estimate survival, and two robust design models to estimate both abundance and survival. We then used simulation to generate three datasets that represented different sampling designs, including one that mimics our field data, to assess model performance and compare tradeoffs in sampling design. We recommend using the robust design framework when possible as this design and model estimation returned accurate and precise estimates of abundance and survival. This model estimated survival ranging from 0.69–0.95 and capture probability from 0.21–0.25. This design requires consistent sampling of at least three events per year during a closed period, repeated over at least five years, to estimate survival between years. In situations where samples could not be repeated across years, closed population models are likely the most reliable framework in terms of model precision and accuracy. Overall, sampling designs that allow for repeated sampling and align the biology of the study species and the assumptions of the statistical model are likely the most informative approaches for sampling River Cooters and similar species.","PeriodicalId":29892,"journal":{"name":"Ichthyology and Herpetology","volume":"110 1","pages":"354 - 363"},"PeriodicalIF":1.5,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47235992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vanessa Meza-Vargas, Bárbara B. Calegari, N. Lujan, G. A. Ballen, O. T. Oyakawa, L. Sousa, L. R. Py-Daniel, R. Reis
A new species of the rubbernose pleco genus Chaetostoma is described from the Maicuru and Seiko Rivers, a northern tributary of the lower Amazon River and a tributary of the lower Xingu River, respectively, both in Pará State, Brazil. The new species is diagnosed from all congeners, except members of the Chaetostoma anale species group, by having an enlarged second unbranched anal-fin ray with posterior paired dermal flaps. Additionally, the new species is distinguished from its only other currently recognized congeners from rivers draining the Guiana Shield (C. jegui and C. vasquezi) by having a smaller opercle and a supraoccipital excrescence undeveloped, comprising a simple skin area present in juveniles and absent in adults. A revised multi-locus phylogeny for the species of Chaetostoma is presented, and the Chaetostoma anale species group is discussed and rearranged. Uma nova espécie de Chaetostoma é descrita dos rios Maicuru, um afluente norte do baixo rio Amazonas, e Seiko, um afluente do baixo rio Xingu, ambos no estado do Pará, Brasil. A nova espécie é diagnosticada de todos os seus congêneres, exceto membros do grupo Chaetostoma anale, por apresentar o segundo raio não ramificado da nadadeira anal aumentado e com abas dérmicas posteriores. Além disso, a nova espécie se distingue dos únicos outros congêneres atualmente reconhecidos do Escudo das Guianas (C. jegui e C. vasquezi) por ter o opérculo menor e a protuberância supraoccipital não desenvolvida, composta por uma área de pele simples em juvenis e ausente em adultos. Uma filogenia multilocus revisada para as espécies de Chaetostoma é apresentada e o grupo Chaetostoma anale é discutido e reorganizado.
{"title":"A New Species of Chaetostoma (Siluriformes: Loricariidae) Expands the Distribution of Rubbernose Plecos Eastward into the Lower Amazon Basin of Brazil","authors":"Vanessa Meza-Vargas, Bárbara B. Calegari, N. Lujan, G. A. Ballen, O. T. Oyakawa, L. Sousa, L. R. Py-Daniel, R. Reis","doi":"10.1643/i2021068","DOIUrl":"https://doi.org/10.1643/i2021068","url":null,"abstract":"A new species of the rubbernose pleco genus Chaetostoma is described from the Maicuru and Seiko Rivers, a northern tributary of the lower Amazon River and a tributary of the lower Xingu River, respectively, both in Pará State, Brazil. The new species is diagnosed from all congeners, except members of the Chaetostoma anale species group, by having an enlarged second unbranched anal-fin ray with posterior paired dermal flaps. Additionally, the new species is distinguished from its only other currently recognized congeners from rivers draining the Guiana Shield (C. jegui and C. vasquezi) by having a smaller opercle and a supraoccipital excrescence undeveloped, comprising a simple skin area present in juveniles and absent in adults. A revised multi-locus phylogeny for the species of Chaetostoma is presented, and the Chaetostoma anale species group is discussed and rearranged. Uma nova espécie de Chaetostoma é descrita dos rios Maicuru, um afluente norte do baixo rio Amazonas, e Seiko, um afluente do baixo rio Xingu, ambos no estado do Pará, Brasil. A nova espécie é diagnosticada de todos os seus congêneres, exceto membros do grupo Chaetostoma anale, por apresentar o segundo raio não ramificado da nadadeira anal aumentado e com abas dérmicas posteriores. Além disso, a nova espécie se distingue dos únicos outros congêneres atualmente reconhecidos do Escudo das Guianas (C. jegui e C. vasquezi) por ter o opérculo menor e a protuberância supraoccipital não desenvolvida, composta por uma área de pele simples em juvenis e ausente em adultos. Uma filogenia multilocus revisada para as espécies de Chaetostoma é apresentada e o grupo Chaetostoma anale é discutido e reorganizado.","PeriodicalId":29892,"journal":{"name":"Ichthyology and Herpetology","volume":"110 1","pages":"364 - 377"},"PeriodicalIF":1.5,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41752287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Joining the ranks of vertebrates that glow is the Pacific Spiny Lumpsucker, Eumicrotremus orbis, a subtidal species widely distributed across the North Pacific Ocean. Aside from their charismatic appearance, the Pacific Spiny Lumpsucker is known for its ventral suction disc that is used to stick to substrates amid changing currents and tides. Here we show that red lumpsuckers, which are usually male and a deep red color under broad-spectrum light, fluoresce bright red under ultraviolet (UV) light and blue light (360–460 nm), while green color morphs (usually female) do not. In all color morphs, the suctorial disc glows green-yellow. The red glow of the males matches the red glow of encrusting algae in their nesting areas, while the suctorial disc may be a signaling system. The green and red fluorescence observed in red lumpsuckers is the rarest fluorescent pattern and is only seen in 17 families of marine fishes. Pacific Spiny Lumpsuckers are cryptically colored under broad-spectrum light; our observed fluorescence suggests a potential avenue of communication and camouflage in an environment where red light is absent or rare.
{"title":"Dimorphic Fluorescence in the Pacific Spiny Lumpsucker","authors":"K. Cohen, A. Summers","doi":"10.1643/i2021019","DOIUrl":"https://doi.org/10.1643/i2021019","url":null,"abstract":"Joining the ranks of vertebrates that glow is the Pacific Spiny Lumpsucker, Eumicrotremus orbis, a subtidal species widely distributed across the North Pacific Ocean. Aside from their charismatic appearance, the Pacific Spiny Lumpsucker is known for its ventral suction disc that is used to stick to substrates amid changing currents and tides. Here we show that red lumpsuckers, which are usually male and a deep red color under broad-spectrum light, fluoresce bright red under ultraviolet (UV) light and blue light (360–460 nm), while green color morphs (usually female) do not. In all color morphs, the suctorial disc glows green-yellow. The red glow of the males matches the red glow of encrusting algae in their nesting areas, while the suctorial disc may be a signaling system. The green and red fluorescence observed in red lumpsuckers is the rarest fluorescent pattern and is only seen in 17 families of marine fishes. Pacific Spiny Lumpsuckers are cryptically colored under broad-spectrum light; our observed fluorescence suggests a potential avenue of communication and camouflage in an environment where red light is absent or rare.","PeriodicalId":29892,"journal":{"name":"Ichthyology and Herpetology","volume":"110 1","pages":"350 - 353"},"PeriodicalIF":1.5,"publicationDate":"2022-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44930036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Male–male aggressive encounters in lizards may involve physical confrontation or the use of multiple cues to signal fighting ability. Behavioral, chromatic, and morphological traits may be associated to reinforce gradual messages to escalate or deescalate interactions during encounters. Our first aim was to provide a detailed ethogram of male–male aggressive encounters in the social lizard Tropidurus spinulosus. Then, we aimed to elucidate the association among behaviors and morphological and chromatic characters. Our results showed several behavioral displays organized in sequential phases, with two displays being characteristic of this species; furthermore, increasingly threatening displays may be repeated several times before reaching physical aggression. Males that dominated the encounters usually had more extended color bands in the most visible body parts, lower body condition, and preferentially had performed pushup early in the bout, whereas males that were ultimately chased had high color band extension in the chest and high testicular volume and performed more lateral compression and head-swipe escalating readily to physical aggression by biting the opponent. In conclusion, the behavioral displays employed by different males were associated with their morphological and chromatic characters, highlighting the existence of signaling strategies among individuals.
{"title":"Relationships among Behavior, Chromatism, and Morphology in Male Aggressive Encounters in Tropidurus spinulosus","authors":"N. Rossi, M. Chiaraviglio, G. Cardozo","doi":"10.1643/h2021025","DOIUrl":"https://doi.org/10.1643/h2021025","url":null,"abstract":"Male–male aggressive encounters in lizards may involve physical confrontation or the use of multiple cues to signal fighting ability. Behavioral, chromatic, and morphological traits may be associated to reinforce gradual messages to escalate or deescalate interactions during encounters. Our first aim was to provide a detailed ethogram of male–male aggressive encounters in the social lizard Tropidurus spinulosus. Then, we aimed to elucidate the association among behaviors and morphological and chromatic characters. Our results showed several behavioral displays organized in sequential phases, with two displays being characteristic of this species; furthermore, increasingly threatening displays may be repeated several times before reaching physical aggression. Males that dominated the encounters usually had more extended color bands in the most visible body parts, lower body condition, and preferentially had performed pushup early in the bout, whereas males that were ultimately chased had high color band extension in the chest and high testicular volume and performed more lateral compression and head-swipe escalating readily to physical aggression by biting the opponent. In conclusion, the behavioral displays employed by different males were associated with their morphological and chromatic characters, highlighting the existence of signaling strategies among individuals.","PeriodicalId":29892,"journal":{"name":"Ichthyology and Herpetology","volume":"110 1","pages":"340 - 349"},"PeriodicalIF":1.5,"publicationDate":"2022-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47522801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
New genetic and morphological data support the recognition of a distinct monophyletic group, the Cyphocharax saladensis clade, which includes C. vanderi, C. saladensis, C. boiadeiro, and a new species. This four-species group can be recognized by modifications in the laterosensory system with instances of incomplete or interrupted poring, by the ontogenetic development of the lateral line with larger specimens having a more developed laterosensory system, and by the presence of a patch of dark pigmentation over the caudal peduncle. The new species is described from the upper Rio Correntes, an upland tributary of the upper Rio Paraguai in central Brazil and is diagnosed by the presence of a thin longitudinal black stripe, by the variable shapes of the dark blotches on the caudal peduncle, and by morphometric and meristic data. New mitochondrial data from paratypes provide clear evidence of genetic distinction between the new species and congeners, and additionally place it as the sister species to C. boiadeiro from the upper Rio Araguaia. Based on the updated molecular phylogeny and biogeographic information, we propose an evolutionary hypothesis with four events of river captures with subsequent allopatric speciation of the new species and C. boiadeiro in the Correntes and Araguaia systems. The new species is suggested to be categorized as Near Threatened, living in a strongly impacted region of the Brazilian Cerrado.
{"title":"Phylogenetic Evidence for the Cyphocharax saladensis Clade with Description of a New Species of Cyphocharax Endemic to the Upper Rio Paraguai Basin (Teleostei: Curimatidae)","authors":"B. F. Melo, L. F. C. Tencatt, Cláudio Oliveira","doi":"10.1643/i2021057","DOIUrl":"https://doi.org/10.1643/i2021057","url":null,"abstract":"New genetic and morphological data support the recognition of a distinct monophyletic group, the Cyphocharax saladensis clade, which includes C. vanderi, C. saladensis, C. boiadeiro, and a new species. This four-species group can be recognized by modifications in the laterosensory system with instances of incomplete or interrupted poring, by the ontogenetic development of the lateral line with larger specimens having a more developed laterosensory system, and by the presence of a patch of dark pigmentation over the caudal peduncle. The new species is described from the upper Rio Correntes, an upland tributary of the upper Rio Paraguai in central Brazil and is diagnosed by the presence of a thin longitudinal black stripe, by the variable shapes of the dark blotches on the caudal peduncle, and by morphometric and meristic data. New mitochondrial data from paratypes provide clear evidence of genetic distinction between the new species and congeners, and additionally place it as the sister species to C. boiadeiro from the upper Rio Araguaia. Based on the updated molecular phylogeny and biogeographic information, we propose an evolutionary hypothesis with four events of river captures with subsequent allopatric speciation of the new species and C. boiadeiro in the Correntes and Araguaia systems. The new species is suggested to be categorized as Near Threatened, living in a strongly impacted region of the Brazilian Cerrado.","PeriodicalId":29892,"journal":{"name":"Ichthyology and Herpetology","volume":"110 1","pages":"327 - 339"},"PeriodicalIF":1.5,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45488702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ghost electric knifefishes (Gymnotiformes: Apteronotidae) are a dominant component of the species diversity and biomass of large lowland rivers in Greater Amazonia, including 77 species that exhibit diverse craniofacial morphologies associated with trophic and secondary sexual traits. Here we use open-source computed micro-tomography (µCT) scans to generate 3D reconstructions for a majority of apteronotid species and almost all valid genera, and geometric morphometric and phylogenetic analyses to explore patterns of skull evolution. As with most vertebrates, principal component 1 (PC1) summarizes variance from brachycephalic to dolichocephalic morphologies, previously described as heterocephaly, and PC2 summarizes variance from recurved (upturned) to decurved (downturned) snout morphologies, described here as heterorhynchy. Phylomorphospace and traitogram analyses found instances of both convergent and divergent evolution along both of the first two PC axes, as well as a preponderance of clades characterized by morphological stasis or phylogenetic conservatism. Certain phenotypic combinations predominate among species and clades, including elongated-downturned snouts and foreshortened-upturned snouts, while other phenotypic combinations are not observed, including elongated-upturned snouts and foreshortened-downturned snouts. These results highlight the power of 3D geometric morphometrics in the study of craniofacial evolution and indicate developmental or functional constraints in the evolution of craniofacial phenotypes in an ecologically dominant clade of riverine Amazonian fishes.
{"title":"Mosaic Evolution of Craniofacial Morphologies in Ghost Electric Fishes (Gymnotiformes: Apteronotidae)","authors":"K. Ford, Maxwell J. Bernt, A. Summers, J. Albert","doi":"10.1643/i2021016","DOIUrl":"https://doi.org/10.1643/i2021016","url":null,"abstract":"Ghost electric knifefishes (Gymnotiformes: Apteronotidae) are a dominant component of the species diversity and biomass of large lowland rivers in Greater Amazonia, including 77 species that exhibit diverse craniofacial morphologies associated with trophic and secondary sexual traits. Here we use open-source computed micro-tomography (µCT) scans to generate 3D reconstructions for a majority of apteronotid species and almost all valid genera, and geometric morphometric and phylogenetic analyses to explore patterns of skull evolution. As with most vertebrates, principal component 1 (PC1) summarizes variance from brachycephalic to dolichocephalic morphologies, previously described as heterocephaly, and PC2 summarizes variance from recurved (upturned) to decurved (downturned) snout morphologies, described here as heterorhynchy. Phylomorphospace and traitogram analyses found instances of both convergent and divergent evolution along both of the first two PC axes, as well as a preponderance of clades characterized by morphological stasis or phylogenetic conservatism. Certain phenotypic combinations predominate among species and clades, including elongated-downturned snouts and foreshortened-upturned snouts, while other phenotypic combinations are not observed, including elongated-upturned snouts and foreshortened-downturned snouts. These results highlight the power of 3D geometric morphometrics in the study of craniofacial evolution and indicate developmental or functional constraints in the evolution of craniofacial phenotypes in an ecologically dominant clade of riverine Amazonian fishes.","PeriodicalId":29892,"journal":{"name":"Ichthyology and Herpetology","volume":"110 1","pages":"315 - 326"},"PeriodicalIF":1.5,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44746184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Compensatory growth, where an organism can grow faster during recovery from low resource periods, is a mechanism used by a wide variety of taxa to mitigate previous deficiencies. Here we present experimental data to test whether pond-breeding salamander juveniles raised in different quality larval habitats can catch up to larger cohort members after metamorphosis. We reared larval Spotted Salamanders (Ambystoma maculatum) in ponds of differing habitat quality resulting in large size differences at metamorphosis. We then kept juveniles in the lab for a year, fed them ad libitum, and measured their growth at three time points post-metamorphosis. We found large differences in size at metamorphosis related to larval habitat, but salamanders that were small at metamorphosis remained smaller a year later and relative growth rates were equal across all metamorphic sizes. Thus, we have little evidence that juveniles can compensate for small size by growing more in the year after metamorphosis, even in conditions of unlimited food. Our data suggest compensatory growth in amphibians may be species-specific, and that poor quality larval environments may be a disadvantage during subsequent life stages.
{"title":"Juvenile Salamanders Do Not Exhibit Compensatory Growth Post-metamorphosis in an Experimental Setting","authors":"Freya E. Rowland, Jacob J. Burkhart","doi":"10.1643/h2021067","DOIUrl":"https://doi.org/10.1643/h2021067","url":null,"abstract":"Compensatory growth, where an organism can grow faster during recovery from low resource periods, is a mechanism used by a wide variety of taxa to mitigate previous deficiencies. Here we present experimental data to test whether pond-breeding salamander juveniles raised in different quality larval habitats can catch up to larger cohort members after metamorphosis. We reared larval Spotted Salamanders (Ambystoma maculatum) in ponds of differing habitat quality resulting in large size differences at metamorphosis. We then kept juveniles in the lab for a year, fed them ad libitum, and measured their growth at three time points post-metamorphosis. We found large differences in size at metamorphosis related to larval habitat, but salamanders that were small at metamorphosis remained smaller a year later and relative growth rates were equal across all metamorphic sizes. Thus, we have little evidence that juveniles can compensate for small size by growing more in the year after metamorphosis, even in conditions of unlimited food. Our data suggest compensatory growth in amphibians may be species-specific, and that poor quality larval environments may be a disadvantage during subsequent life stages.","PeriodicalId":29892,"journal":{"name":"Ichthyology and Herpetology","volume":"110 1","pages":"292 - 298"},"PeriodicalIF":1.5,"publicationDate":"2022-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44089321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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