Maribel Méndez-Tepepa, Kevin I. Medina-Bello, Edelmira García-Nieto, Libertad Juárez-Santa Cruz
The contamination of aquatic systems by anthropogenic activities may impact amphibian populations by causing malformation and death in tadpoles. However, there often needs to be more information regarding environmental pollutants' effects on amphibians, such as contaminated systems from the state of Tlaxcala in Mexico. This study reports on morphological abnormalities observed in Lithobates spectabilis tadpoles found in a stream of three sites monitored in Tlaxcala. The tadpoles presented swollen heads, edema, intestinal hemorrhage, anomalies in the mouth, a deviated tail, and underdeveloped tail fins. We hypothesise that these abnormalities have been caused by exposure to contamination from nearby communities, including garbage and sewage pumped directly into the stream. This research provides the first report on the potential adverse effects of contaminant exposure on tadpole development and morphology in this region. Identifying malformations in tadpoles could help detect contaminants in aquatic systems for further analysis. Keywords: Lithobates spectabilis, pollutants, anthropogenic, edema, abnormalities
{"title":"Morphological anomalies of tadpoles from a contaminated stream in the state of Tlaxcala, Mexico","authors":"Maribel Méndez-Tepepa, Kevin I. Medina-Bello, Edelmira García-Nieto, Libertad Juárez-Santa Cruz","doi":"10.33256/33.4.111114","DOIUrl":"https://doi.org/10.33256/33.4.111114","url":null,"abstract":"The contamination of aquatic systems by anthropogenic activities may impact amphibian populations by causing malformation and death in tadpoles. However, there often needs to be more information regarding environmental pollutants' effects on amphibians, such as contaminated systems from the state of Tlaxcala in Mexico. This study reports on morphological abnormalities observed in Lithobates spectabilis tadpoles found in a stream of three sites monitored in Tlaxcala. The tadpoles presented swollen heads, edema, intestinal hemorrhage, anomalies in the mouth, a deviated tail, and underdeveloped tail fins. We hypothesise that these abnormalities have been caused by exposure to contamination from nearby communities, including garbage and sewage pumped directly into the stream. This research provides the first report on the potential adverse effects of contaminant exposure on tadpole development and morphology in this region. Identifying malformations in tadpoles could help detect contaminants in aquatic systems for further analysis. Keywords: Lithobates spectabilis, pollutants, anthropogenic, edema, abnormalities","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135323339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wen Hao Shi, Hai Ying Li, Wen Long Lu, Tong Lei Yu
According to Richards' hypothesis, algae or cells in the intestinal tract has been considered the cellular inhibitory factor, when they fall off and hide in the faeces, excreted together with the faeces. If the animals feed on these faeces with algae or cells, and bring them into their systems, then the cellular inhibitory factor would play the main responsibility for growth inhibition. Here, we surveyed the effects of different combinations of faeces and food level on growth rates, survivorship, larval age and mass, and SVL at metamorphosis of the Chinese brown frog Rana chensinensis. Our results showed that food level can influence the length of the larval period of Chinese brown frog tadpoles, suggesting that delayed metamorphosis is caused by low food supply, indicative of a function of effective energy. Our data also clearly indicated that tadpoles in the presence of faeces were on average larger in body mass than those in the absence of faeces, which failed to obey Richards' hypothesis. Moreover, our results found evidence that faeces have a positive effect on the growth rate of tadpoles. Thus, there is no evidence for Richards' hypothesis, suggesting that this novel mechanism is selected for where coprophagy is likely to prove profitable, irrespective of the abundance of alternative food. Keywords: Rana chensinensis, Richards' hypothesis, faecal material, mass at metamorphosis, growth rate
{"title":"The plasticity of metamorphic traits in the Chinese brown frog tadpoles fails to obey Richards' hypothesis","authors":"Wen Hao Shi, Hai Ying Li, Wen Long Lu, Tong Lei Yu","doi":"10.33256/33.4.97102","DOIUrl":"https://doi.org/10.33256/33.4.97102","url":null,"abstract":"According to Richards' hypothesis, algae or cells in the intestinal tract has been considered the cellular inhibitory factor, when they fall off and hide in the faeces, excreted together with the faeces. If the animals feed on these faeces with algae or cells, and bring them into their systems, then the cellular inhibitory factor would play the main responsibility for growth inhibition. Here, we surveyed the effects of different combinations of faeces and food level on growth rates, survivorship, larval age and mass, and SVL at metamorphosis of the Chinese brown frog Rana chensinensis. Our results showed that food level can influence the length of the larval period of Chinese brown frog tadpoles, suggesting that delayed metamorphosis is caused by low food supply, indicative of a function of effective energy. Our data also clearly indicated that tadpoles in the presence of faeces were on average larger in body mass than those in the absence of faeces, which failed to obey Richards' hypothesis. Moreover, our results found evidence that faeces have a positive effect on the growth rate of tadpoles. Thus, there is no evidence for Richards' hypothesis, suggesting that this novel mechanism is selected for where coprophagy is likely to prove profitable, irrespective of the abundance of alternative food. Keywords: Rana chensinensis, Richards' hypothesis, faecal material, mass at metamorphosis, growth rate","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135323137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Curt Barnes, Colin Strine, Bartosz Nadolski, Jacques Hill III, Pongthep Suwanwaree, Taksin Artchawakom, Surachit Waengsothorn
Sexual dimorphism is expressed in many taxa as a form of resource partitioning and as a response to unique challenges faced by male and female organisms. We investigated this phenomenon for an arboreal green pit viper species, Trimeresurus macrops, previously suggested to display obvious sexual dimorphism. We evaluated seven external characters and scaled mass index (SMI) of 73 vipers (N = 32 males, N = 41 females) obtained during night surveys and opportunistic searches in north-east Thailand from January 2015–January 2017. We utilised Bayesian inference to investigate the influence of sex, gravidity, and rural habitat disturbance on sexual dimorphism of T. macrops, and we provide 95 % highest density intervals (HDI) for the difference in means (posterior distribution). We also present ecologically relevant probabilities of observing dimorphism for each external character and SMI by sex, gravidity (gravid or not), and habitat type (rural or forest). Females were larger than males in both forested and rural habitat, females in rural habitat were larger than forest females, and all males displayed a conspicuous white eye-stripe. When gravid females were excluded from analyses, probability of observing dimorphism drastically decreased. Knowledge of niche partitioning and the specific challenges encountered by males and females, gravid and non-gravid females, and individuals persisting in rural habitats will prove valuable for conservation and snakebite mitigation of T. macrops. Keywords: Difference of body size, south-east Asia, Bayesian inference, arboreal viper ความแตกต่างระหว่างเพศ (sexual dimorphism) ถูกปรากฎในอนุกรมวิธานสัตว์ว่าเป็นรูปแบบหนึ่งของการแบ่งปันทรัพยากร (resource partitioning) และการท้าทายจำเพาะจากสิ่งมีชีวิตเพศผู้และเพศเมีย เราศึกษาปรากฏการณ์นี้ในกลุ่มงูเขียวหางไห้ที่มีถิ่นอาศัยอยู่บนต้นไม้ ชนิดพันธุ์ งูเขียวหางไหม้ตาโต Trimeresurus macrops ซึ่งได้รับการเสนอในการศึกษาก่อนหน้าว่ามีการแสดงออกของความแตกต่างระหว่างเพศอย่างชัดเจน นักวิจัยทำการประเมินลักษณะภายนอกทั้ง 7 ลักษณะและScaled mass index (SMI) ของงูเขียวหางไหม้จำนวน 73 ตัว (ตัวผู้ 32 ตัว, ตัวเมีย 41 ตัว) จากการสำรวจตอนกลางคืนและการสำรวจตามโอกาสในพื้นที่ภาคตะวันออกเฉียงเหนือของประเทศไทยตั้งแต่เดือนมกราคม พ.ศ. 2558 - มกราคม พ.ศ. 2560 เราใช้การอนุมานแบบเบย์เพื่อตรวจสอบอิทธิพลของเพศ การตั้งครรภ์ และการรบกวนถิ่นอาศัยในพื้นที่เกษตรกรรมต่อความแตกต่างระหว่างเพศของงูเขียวหางไหม้ตาโต T. macrops และเราให้ช่วง HDI อยู่ที่ 95% สำหรับความแตกต่างของค่าเฉลี่ย (การแจกแจงหลัง) นอกจากนี้ เรานำเสนอความน่าจะเป็นที่เกี่ยวข้องกับระบบนิเวศในการสังเกตความแตกต่างของลักษณะภายนอกและ SMI ตามเพศ การตั้งครรภ์ (มีหรือไม่มี) และประเภทที่อยู่อาศัย (พื้นที่เกษตรกรรมหรือป่า) การศึกษาพบว่า งูเขียวหางไหม้ตัวเมียมีขนาดใหญ่กว่าตัวผู้ทั้งที่อาศัยในป่าและพื้นที่เกษตรกรรม โดยงูเขียวหางไหม้ตัวเมียในที่อยู่อาศัยพื้นที่เกษตรกรรมจะมีขนาดใหญ่กว่าที่พบในป่า และตัวผู้ทุกตัวมีแถบตาสีขาวที่สังเกตเห็นชัดเจน ทั้งนี้เมื่องูเขียวหางไหม้เพศเมียที่ตั้งครรภ์ถูกแยกออกจากการวิเคราะห์ ค่าความน่าจะเป็นในการสังเกตความแตกต่างระหว่างเพศถูกลดทอน
{"title":"Bayesian insights into Green Pit Viper Trimeresurus (Cryptelytrops) macrops sexual dimorphism with respect to influence of gravidity and habitat disturbance","authors":"Curt Barnes, Colin Strine, Bartosz Nadolski, Jacques Hill III, Pongthep Suwanwaree, Taksin Artchawakom, Surachit Waengsothorn","doi":"10.33256/33.4.8896","DOIUrl":"https://doi.org/10.33256/33.4.8896","url":null,"abstract":"Sexual dimorphism is expressed in many taxa as a form of resource partitioning and as a response to unique challenges faced by male and female organisms. We investigated this phenomenon for an arboreal green pit viper species, Trimeresurus macrops, previously suggested to display obvious sexual dimorphism. We evaluated seven external characters and scaled mass index (SMI) of 73 vipers (N = 32 males, N = 41 females) obtained during night surveys and opportunistic searches in north-east Thailand from January 2015–January 2017. We utilised Bayesian inference to investigate the influence of sex, gravidity, and rural habitat disturbance on sexual dimorphism of T. macrops, and we provide 95 % highest density intervals (HDI) for the difference in means (posterior distribution). We also present ecologically relevant probabilities of observing dimorphism for each external character and SMI by sex, gravidity (gravid or not), and habitat type (rural or forest). Females were larger than males in both forested and rural habitat, females in rural habitat were larger than forest females, and all males displayed a conspicuous white eye-stripe. When gravid females were excluded from analyses, probability of observing dimorphism drastically decreased. Knowledge of niche partitioning and the specific challenges encountered by males and females, gravid and non-gravid females, and individuals persisting in rural habitats will prove valuable for conservation and snakebite mitigation of T. macrops. Keywords: Difference of body size, south-east Asia, Bayesian inference, arboreal viper ความแตกต่างระหว่างเพศ (sexual dimorphism) ถูกปรากฎในอนุกรมวิธานสัตว์ว่าเป็นรูปแบบหนึ่งของการแบ่งปันทรัพยากร (resource partitioning) และการท้าทายจำเพาะจากสิ่งมีชีวิตเพศผู้และเพศเมีย เราศึกษาปรากฏการณ์นี้ในกลุ่มงูเขียวหางไห้ที่มีถิ่นอาศัยอยู่บนต้นไม้ ชนิดพันธุ์ งูเขียวหางไหม้ตาโต Trimeresurus macrops ซึ่งได้รับการเสนอในการศึกษาก่อนหน้าว่ามีการแสดงออกของความแตกต่างระหว่างเพศอย่างชัดเจน นักวิจัยทำการประเมินลักษณะภายนอกทั้ง 7 ลักษณะและScaled mass index (SMI) ของงูเขียวหางไหม้จำนวน 73 ตัว (ตัวผู้ 32 ตัว, ตัวเมีย 41 ตัว) จากการสำรวจตอนกลางคืนและการสำรวจตามโอกาสในพื้นที่ภาคตะวันออกเฉียงเหนือของประเทศไทยตั้งแต่เดือนมกราคม พ.ศ. 2558 - มกราคม พ.ศ. 2560 เราใช้การอนุมานแบบเบย์เพื่อตรวจสอบอิทธิพลของเพศ การตั้งครรภ์ และการรบกวนถิ่นอาศัยในพื้นที่เกษตรกรรมต่อความแตกต่างระหว่างเพศของงูเขียวหางไหม้ตาโต T. macrops และเราให้ช่วง HDI อยู่ที่ 95% สำหรับความแตกต่างของค่าเฉลี่ย (การแจกแจงหลัง) นอกจากนี้ เรานำเสนอความน่าจะเป็นที่เกี่ยวข้องกับระบบนิเวศในการสังเกตความแตกต่างของลักษณะภายนอกและ SMI ตามเพศ การตั้งครรภ์ (มีหรือไม่มี) และประเภทที่อยู่อาศัย (พื้นที่เกษตรกรรมหรือป่า) การศึกษาพบว่า งูเขียวหางไหม้ตัวเมียมีขนาดใหญ่กว่าตัวผู้ทั้งที่อาศัยในป่าและพื้นที่เกษตรกรรม โดยงูเขียวหางไหม้ตัวเมียในที่อยู่อาศัยพื้นที่เกษตรกรรมจะมีขนาดใหญ่กว่าที่พบในป่า และตัวผู้ทุกตัวมีแถบตาสีขาวที่สังเกตเห็นชัดเจน ทั้งนี้เมื่องูเขียวหางไหม้เพศเมียที่ตั้งครรภ์ถูกแยกออกจากการวิเคราะห์ ค่าความน่าจะเป็นในการสังเกตความแตกต่างระหว่างเพศถูกลดทอน","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135323343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Although suffered from many evolutionary disadvantages, asexual species benefit from their high efficiency to build clonal populations in a novel habitat. Here we report that a parthenogenetic mourning gecko Lepidodactylus lugubris continuously laid 12 clutches within two years. The egg-laying period lasted from mid-April to late October, and the egg-laying interval ranged between 24 and 73 days with a mean of 34.4 days. Referring to this fecundity, a female gecko could reproduce up to 24 clonal female offspring every year, and expand the population size in an efficient way much faster than most bisexual species. The intensive and efficient egg-laying tempo, associated with the parthenogenetic breeding mode, are crucial factors which facilitated their successful colonisation into many islands. Keywords: clonal population, cost of sex, invariant clutch size, invasive species
{"title":"Intensive and efficient egg-laying tempo of the parthenogenesis mourning gecko Lepidodactylus lugubris","authors":"Tsui-Wen Li, Jhan-Wei Lin, Si-Min Lin","doi":"10.33256/33.4.115118","DOIUrl":"https://doi.org/10.33256/33.4.115118","url":null,"abstract":"Although suffered from many evolutionary disadvantages, asexual species benefit from their high efficiency to build clonal populations in a novel habitat. Here we report that a parthenogenetic mourning gecko Lepidodactylus lugubris continuously laid 12 clutches within two years. The egg-laying period lasted from mid-April to late October, and the egg-laying interval ranged between 24 and 73 days with a mean of 34.4 days. Referring to this fecundity, a female gecko could reproduce up to 24 clonal female offspring every year, and expand the population size in an efficient way much faster than most bisexual species. The intensive and efficient egg-laying tempo, associated with the parthenogenetic breeding mode, are crucial factors which facilitated their successful colonisation into many islands. Keywords: clonal population, cost of sex, invariant clutch size, invasive species","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135323140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vanessa M. Marshall, Patrick J. McLaughlin, Juvencio Eko Mengue, Liscinia Josefa Bindang, Lauren A. Scheinberg, Christian Irian, Rayna C. Bell, C. Guilherme Becker
The effects of host ecology and environmental conditions on infection dynamics of the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) have been documented in several tropical and montane regions across the globe. These interactions are often complex and unique at local scales. Data on the historical and current chytridiomycosis-amphibian system is largely lacking in Africa, especially central Africa. We conducted the first survey of Bd in continental Equatorial Guinea in 2019, and extensively sampled the land-bridge island, Bioko, in 2011 and 2019. Our results provide novel information on the distribution and prevalence of Bd in Equatorial Guinea and demonstrate the effects of host developmental mode and elevation on Bd infections. We found that Bd infection loads are positively linked with elevation and that direct-developing species have higher average Bd loads than aquatic breeding species at all elevations. These patterns corroborate previous findings in afrotropical amphibian assemblages. Additionally, our study confirms the presence of Bd in continental Equatorial Guinea, providing updated information on the distribution of Bd in central Africa, and confirming the need for careful monitoring of this biodiverse region. Keywords: Bioko, Equatorial Guinea, Bd infection load, amphibian conservation Los efectos de la ecología del huésped y las condiciones ambientales en la dinámica de infección del hongo quítrido anfibio Batrachochytrium dendrobatidis (Bd) se han documentado en varias regiones tropicales y montañosas de todo el mundo. Estas interacciones suelen ser complejas y únicas a escala local. Los datos sobre el sistema quitridiomicosis-anfibios histórico y actual faltan en gran medida en África, especialmente en África central. Realizamos la primera encuesta de Bd en Guinea Ecuatorial continental en 2019, y un muestreo extenso de la isla Bioko en 2011 y 2019. Nuestros resultados brindan información novedosa sobre la distribución y prevalencia de Bd en Guinea Ecuatorial y demuestran el efecto del modo de desarrollo del huésped y la elevación de las infecciones por Bd. Descubrimos que las cargas de infección por Bd están relacionadas positivamente con la elevación y que las especies en desarrollo directo tienen cargas promedio de Bd más altas que las especies acuáticas reproductoras a lo largo de la elevación. Estos patrones corroboran hallazgos previos en conjuntos de anfibios afrotropicales. Además, nuestro estudio confirma la presencia de Bd en Guinea Ecuatorial continental, proporcionando información actualizada sobre la distribución de Bd en África Central y confirmando la necesidad de un seguimiento cuidadoso de esta región biodiversa.
寄主生态和环境条件对两栖壶菌水蛭壶菌(Batrachochytrium dendroatidis, Bd)感染动态的影响已经在全球多个热带和山地地区得到了记录。这些相互作用在局部尺度上往往是复杂和独特的。在非洲，特别是中非，历史上和现在的壶菌病-两栖动物系统的数据很大程度上缺乏。我们于2019年在赤道几内亚大陆进行了首次生物多样性调查，并于2011年和2019年对陆桥岛比奥科岛进行了广泛采样。我们的研究结果为赤道几内亚Bd的分布和流行提供了新的信息，并证明了宿主发育模式和海拔对Bd感染的影响。我们发现，Bd感染负荷与海拔高度呈正相关，在所有海拔高度，直接发育物种的平均Bd负荷都高于水生繁殖物种。这些模式证实了以前在热带两栖动物群落中的发现。此外，我们的研究证实了Bd在赤道几内亚大陆的存在，提供了Bd在中非分布的最新信息，并确认了对这一生物多样性地区进行仔细监测的必要性。关键词:生物科，赤道几内亚，Bd感染负荷，两栖动物保护感染效应:ecología赤道几内亚线虫感染效应:dinámica赤道几内亚线虫感染效应:dinámica赤道几内亚线虫感染效应:quítrido赤道几内亚线虫感染效应:dinámica赤道几内亚线虫感染效应:quítrido赤道几内亚线虫感染效应:dinámica赤道几内亚线虫感染效应:quítrido赤道几内亚线虫感染效应:quítrido热带地区线虫感染效应:montañosas赤道几内亚线虫感染效应:quítrido热带地区线虫感染效应:montañosas赤道几内亚线虫感染效应Estas的交互是通过únicas和escala local实现的。研究结果表明，在大肠杆菌中，特别是在África中央，细菌的实际感染程度为África。2019年获得几内亚行政大陆地区的首期发展许可，2011年至2019年获得比奥科岛扩展许可。都能resultados brindan给novedosa尤其la distribucion prevalencia de Bd en几内亚Ecuatorial y demuestran el efecto▽modo de desarrollo▽huesped y la elevacion de las infecciones穷Bd。Descubrimos,拉斯维加斯cargas de infeccion为什么Bd范围relacionadas positivamente con la elevacion y,拉斯维加斯especies en desarrollo导演tienen cargas promedio de Bd mas阿特拉斯,拉斯维加斯especies acuaticas reproductoras lo庄严的de la elevacion。Estos patronones确证hallazgos preos en conjuntos de antifibios afrotropicales。Además, nuestro estudio confirma la presencia de Bd en Guinea, Ecuatorial continental, proporcionando información actualizada sobre la distribución de Bd en África Central y confirmando la necesidad de un seguimiento cuidadoso de esta región biodiversa。
{"title":"Fungal pathogen infection intensity associated with reproductive mode and elevation in an afrotropical anuran community","authors":"Vanessa M. Marshall, Patrick J. McLaughlin, Juvencio Eko Mengue, Liscinia Josefa Bindang, Lauren A. Scheinberg, Christian Irian, Rayna C. Bell, C. Guilherme Becker","doi":"10.33256/33.4.103110","DOIUrl":"https://doi.org/10.33256/33.4.103110","url":null,"abstract":"The effects of host ecology and environmental conditions on infection dynamics of the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) have been documented in several tropical and montane regions across the globe. These interactions are often complex and unique at local scales. Data on the historical and current chytridiomycosis-amphibian system is largely lacking in Africa, especially central Africa. We conducted the first survey of Bd in continental Equatorial Guinea in 2019, and extensively sampled the land-bridge island, Bioko, in 2011 and 2019. Our results provide novel information on the distribution and prevalence of Bd in Equatorial Guinea and demonstrate the effects of host developmental mode and elevation on Bd infections. We found that Bd infection loads are positively linked with elevation and that direct-developing species have higher average Bd loads than aquatic breeding species at all elevations. These patterns corroborate previous findings in afrotropical amphibian assemblages. Additionally, our study confirms the presence of Bd in continental Equatorial Guinea, providing updated information on the distribution of Bd in central Africa, and confirming the need for careful monitoring of this biodiverse region. Keywords: Bioko, Equatorial Guinea, Bd infection load, amphibian conservation Los efectos de la ecología del huésped y las condiciones ambientales en la dinámica de infección del hongo quítrido anfibio Batrachochytrium dendrobatidis (Bd) se han documentado en varias regiones tropicales y montañosas de todo el mundo. Estas interacciones suelen ser complejas y únicas a escala local. Los datos sobre el sistema quitridiomicosis-anfibios histórico y actual faltan en gran medida en África, especialmente en África central. Realizamos la primera encuesta de Bd en Guinea Ecuatorial continental en 2019, y un muestreo extenso de la isla Bioko en 2011 y 2019. Nuestros resultados brindan información novedosa sobre la distribución y prevalencia de Bd en Guinea Ecuatorial y demuestran el efecto del modo de desarrollo del huésped y la elevación de las infecciones por Bd. Descubrimos que las cargas de infección por Bd están relacionadas positivamente con la elevación y que las especies en desarrollo directo tienen cargas promedio de Bd más altas que las especies acuáticas reproductoras a lo largo de la elevación. Estos patrones corroboran hallazgos previos en conjuntos de anfibios afrotropicales. Además, nuestro estudio confirma la presencia de Bd en Guinea Ecuatorial continental, proporcionando información actualizada sobre la distribución de Bd en África Central y confirmando la necesidad de un seguimiento cuidadoso de esta región biodiversa.","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135323141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. O’Brien, J. Hall, K. O’Brien, Donal Smith, Stewart Angus, R. V. Joglekar, R. Jehle
Processes of island colonisation have long been of interest to biologists. Colonisation events themselves are rarely observed, but the processes involved may be inferred using genetic approaches. We investigated possible means of island colonisation by common toads (Bufo bufo) in western Scotland (the Isle of Skye and five neighbouring small islands), using evidence derived from nuclear microsatellites and mitochondrial (mt) DNA. Levels of microsatellite allelic richness for populations on Skye were high and comparable to adjacent mainland populations, but lower for populations on small islands. Pairwise measures of genetic distances between populations and a clustering algorithm were both suggestive of frequent gene flow between Skye and the mainland. For small islands the levels of genetic differentiation were higher, implying stronger isolation and no evidence for inbreeding. The distribution of mtDNA haplotypes broadly mirrored the genetic structure revealed by microsatellites. Reconciled with existing palaeoclimatological evidence, since the last glaciation, our findings rule out the possibility that the B. bufo populations stem from glacial refugia, or that recent anthropogenic transfer of toads is responsible for their current distribution. The most parsimonious explanation of our data is that the studied inshore islands have been repeatedly colonised via rafting from the mainland or neighbouring islands. This may give us insights into the processes likely to take place when ice sheets retreat poleward as a result of climate change. It also has implications for the colonisation of both native and invasive non-native species, and hence the biosecurity of island refugia.
{"title":"How did the toad get over the sea to Skye? Tracing the colonisation of Scottish inshore islands by common toads (Bufo bufo)","authors":"D. O’Brien, J. Hall, K. O’Brien, Donal Smith, Stewart Angus, R. V. Joglekar, R. Jehle","doi":"10.33256/31.4.204213","DOIUrl":"https://doi.org/10.33256/31.4.204213","url":null,"abstract":"Processes of island colonisation have long been of interest to biologists. Colonisation events themselves are rarely observed, but the processes involved may be inferred using genetic approaches. We investigated possible means of island colonisation by common toads (Bufo bufo) in western Scotland (the Isle of Skye and five neighbouring small islands), using evidence derived from nuclear microsatellites and mitochondrial (mt) DNA. Levels of microsatellite allelic richness for populations on Skye were high and comparable to adjacent mainland populations, but lower for populations on small islands. Pairwise measures of genetic distances between populations and a clustering algorithm were both suggestive of frequent gene flow between Skye and the mainland. For small islands the levels of genetic differentiation were higher, implying stronger isolation\u0000and no evidence for inbreeding. The distribution of mtDNA haplotypes broadly mirrored the genetic structure revealed by microsatellites. Reconciled with existing palaeoclimatological evidence, since the last glaciation, our findings rule out the possibility that the B. bufo populations stem from glacial refugia, or that recent anthropogenic transfer of toads is responsible for their current distribution. The most parsimonious explanation of our data is that the studied inshore islands have been repeatedly colonised via rafting from the mainland or neighbouring islands. This may give us insights into the processes likely to take place when ice sheets retreat poleward as a result of climate change. It also has implications for the colonisation of both native and invasive non-native species, and hence the biosecurity of island refugia.","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45461953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Matthias Renoirt, Marion Cheron, F. Angelier, F. Brischoux
Anthropogenic alterations of habitats can have detrimental consequences for biodiversity. Documenting these effects require monitoring in multiple sites that vary in the degree of alterations over long temporal scales, a task that is challenging. Yet, simple naturalist observations can reveal major ongoing events affecting wild populations, and serve as a basis for further investigations. We quantified breeding parameters of spined toad (Bufo spinosus) populations from forested (preserved) and agricultural (altered) habitats. We found that reproduction did not occur at the sites surrounded by agriculture, while it occurred successfully in ponds from forests. Males were present at all sites, but females, amplexus, egg strings and tadpoles remained absent from agricultural sites. Observations made at the same sites indicated that breeding occurred during previous years. Our observations of habitat- and sex-specific lack of reproduction may have critical consequences for the persistence of populations of a widespread amphibian species in agricultural areas.
{"title":"Unusual lack of reproduction in toad populations from agricultural habitats","authors":"Matthias Renoirt, Marion Cheron, F. Angelier, F. Brischoux","doi":"10.33256/31.4.197200","DOIUrl":"https://doi.org/10.33256/31.4.197200","url":null,"abstract":"Anthropogenic alterations of habitats can have detrimental consequences for biodiversity. Documenting these effects require monitoring in multiple sites that vary in the degree of alterations over long temporal scales, a task that is challenging. Yet, simple naturalist observations can reveal major ongoing events affecting wild populations, and serve as a basis for further investigations. We quantified breeding parameters of spined toad (Bufo spinosus) populations from forested (preserved) and agricultural (altered) habitats. We found that reproduction did not occur at the sites surrounded by agriculture, while it occurred successfully in ponds from forests. Males were present at all sites, but females, amplexus, egg strings and tadpoles remained absent from agricultural sites. Observations made at the same sites indicated that breeding occurred during previous years. Our observations of habitat- and sex-specific lack of reproduction may have critical consequences for the persistence of populations of a widespread amphibian species in agricultural areas.","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46145840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Benefits conferred to animals living in groups may be greater if groups are formed by relatives rather than non-relatives, because cooperating with relatives increases the probability of their own genes being passed on to group offspring (inclusive fitness). Non-social aggregations are formed in response to environmental characteristics, while social aggregations are formed from the attraction among individuals. The attraction or repulsion between individuals is mediated by recognition mechanisms, which mediate important ecological processes and behaviours. Here, we conducted laboratory experiments to test if tadpoles of two sympatric bufonids, Rhinella icterica and R. ornata, are able to recognise siblings. We collected eggs of the two species in the field and raised them in laboratory settings, according to three different methods: siblings and non-siblings reared in separated containers; siblings and non-siblings reared in the same container separated by a plastic net; and eggs from the same spawn reared separately, each one in an individual container. Later, we tested if tadpoles could choose between groups of siblings and non-siblings. The results indicate that tadpoles of neither species were able to discriminate between siblings and non-siblings, regardless of the rearing methods. Therefore, kinship is less important than environmental factors in tadpole aggregation behaviour of these species, and it may be dependent on the balance between costs and benefits. Our results can be used as a start point to better understand tadpole aggregation behaviour and recognition mechanisms in these species.
{"title":"Rhinella icterica and Rhinella ornata (Anura: Bufonidae) tadpoles do not recognise siblings","authors":"Alexandre Polettini Neto, Jaime Bertoluci","doi":"10.33256/31.4.214220","DOIUrl":"https://doi.org/10.33256/31.4.214220","url":null,"abstract":"Benefits conferred to animals living in groups may be greater if groups are formed by relatives rather than non-relatives, because cooperating with relatives increases the probability of their own genes being passed on to group offspring (inclusive fitness). Non-social aggregations are formed in response to environmental characteristics, while social aggregations are\u0000formed from the attraction among individuals. The attraction or repulsion between individuals is mediated by recognition mechanisms, which mediate important ecological processes and behaviours. Here, we conducted laboratory experiments to test if tadpoles of two sympatric bufonids, Rhinella icterica and R. ornata, are able to recognise siblings. We collected eggs of the two species in the field and raised them in laboratory settings, according to three different methods: siblings and non-siblings reared in separated containers; siblings and non-siblings reared in the same container separated by a plastic net; and eggs from the same spawn reared separately, each one in an individual container. Later, we tested if tadpoles could choose between groups of siblings and non-siblings. The results indicate that tadpoles of neither species were able to discriminate between siblings and non-siblings, regardless of the rearing methods. Therefore, kinship is less important than environmental factors in tadpole aggregation behaviour of these species, and it may be dependent on the balance between costs and benefits. Our results can be used as a start point to better understand tadpole aggregation behaviour and recognition mechanisms in these species.","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42779192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Species distribution models (SDMs) are frequently used to characterise current, past or future realised environmental niches. Two recent studies applied different approaches to infer range dynamics in eastern subspecies of the spur-thighed tortoise Testudo graeca Linnaeus, 1758. We discuss differences in the conclusions of the two papers and use multivariate environmental similarity surface (MESS) analyses to show that the results of the study by Turkozan et al. (2021), recently published in the Herpetological Journal, are compromised by extrapolation and therefore have to be interpreted with caution.
{"title":"“Reconstructions of the past distribution of Testudo graeca mitochondrial lineages in the Middle East and Transcaucasia support multiple refugia since the Last Glacial Maximum”: A response to Turkozan et al. (2021)","authors":"F. Ihlow","doi":"10.33256/31.4.201203","DOIUrl":"https://doi.org/10.33256/31.4.201203","url":null,"abstract":"Species distribution models (SDMs) are frequently used to characterise current, past or future realised environmental niches. Two recent studies applied different approaches to infer range dynamics in eastern subspecies of the spur-thighed tortoise Testudo graeca Linnaeus, 1758. We discuss differences in the conclusions of the two papers and use multivariate environmental similarity surface (MESS) analyses to show that the results of the study by Turkozan et al. (2021), recently published in the Herpetological Journal, are compromised by extrapolation and therefore have to be interpreted with caution.","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49332581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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