Pub Date : 2023-12-15DOI: 10.5869/fc.2023.v28-1.27
Jacob T. Westhoff, Hisham A. Abdelrahman, James A. Stoeckel
The spread of invasive crayfish requires invaded habitats to be thermally suitable, and differences in thermal tolerances among species could provide thermal refugia for native crayfish affected by the invader. We estimated upper thermal tolerances for the invasive Faxonius hylas and native F. peruncus and F. quadruncus in Missouri, USA, using critical thermal maxima (CTmax) methodology to determine if there were ecologically exploitable differences in estimates among species and if areas within their distributional ranges exceed their thermal maximums. Estimates of CTmax did not differ among species or sexes but differed among groups acclimated to different temperatures. Additionally, crayfish size had a small, yet significant effect on CTmax estimates with smaller crayfish having lower CTmax estimates than larger crayfish. The similarity among CTmax estimates indicates that for at least upper thermal tolerance, areas thermally available to the native species will also be thermally suitable for the invader. We did not observe water temperatures in the field that exceeded CTmax estimates for any species. However, areas within the mainstem St. Francis River did have warming tolerance estimates of less than 5°C, indicating that establishment of the invader in the mainstem could be limited by water temperature.
{"title":"Upper Thermal Tolerances of Two Native and One Invasive Crayfish in Missouri, USA","authors":"Jacob T. Westhoff, Hisham A. Abdelrahman, James A. Stoeckel","doi":"10.5869/fc.2023.v28-1.27","DOIUrl":"https://doi.org/10.5869/fc.2023.v28-1.27","url":null,"abstract":"\u0000 The spread of invasive crayfish requires invaded habitats to be thermally suitable, and differences in\u0000thermal tolerances among species could provide thermal refugia for native crayfish affected by the\u0000invader. We estimated upper thermal tolerances for the invasive Faxonius hylas and native F. peruncus\u0000and F. quadruncus in Missouri, USA, using critical thermal maxima (CTmax) methodology to determine\u0000if there were ecologically exploitable differences in estimates among species and if areas within their\u0000distributional ranges exceed their thermal maximums. Estimates of CTmax did not differ among species\u0000or sexes but differed among groups acclimated to different temperatures. Additionally, crayfish size had\u0000a small, yet significant effect on CTmax estimates with smaller crayfish having lower CTmax estimates than\u0000larger crayfish. The similarity among CTmax estimates indicates that for at least upper thermal tolerance,\u0000areas thermally available to the native species will also be thermally suitable for the invader. We did not\u0000observe water temperatures in the field that exceeded CTmax estimates for any species. However, areas\u0000within the mainstem St. Francis River did have warming tolerance estimates of less than 5°C, indicating\u0000that establishment of the invader in the mainstem could be limited by water temperature.","PeriodicalId":29940,"journal":{"name":"Freshwater Crayfish","volume":"18 7","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138970630","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}
Pub Date : 2023-12-15DOI: 10.5869/fc.2023.v28-1.11
R. DiStefano, Erica L. Ascani, Robert B. Bratcher, Ashley N. Hrdina, Emile A. Ellingsworth, Brian K. Watson
Comprehensive surveys are critical to conserve and monitor crayfish communities, imperiled species, and detect crayfish invasions. The Missouri portion of the North Fork White River drainage (MONFWR) was never comprehensively surveyed, but adjacent drainage surveys suggested it could harbor species of conservation concern (SOCC). We surveyed the MONFWR to determine crayfish species richness, distributions of potential SOCC, and potential invasive species. We included recent sampling of the Arkansas portion of the drainage for a more holistic assessment of the entire drainage. We examined potential changes in crayfish communities after three decades at 22 previously sampled MONFWR locations. We also collected the first habitat association data for the endemic, Faxonius longidigitus. We detected eight taxa; none that were not known from the drainage. Faxonius neglectus chaenodactylus and Cambarus hubbsi were SOCC; F. n. chaenodactylus was common and abundant in the MONFWR; C. hubbsi was detected at only one site in Arkansas. Faxonius neglectus neglectus and Faxonius virilis were each detected only once and are likely introduced. Intermittent streams harbored diversity and abundance rivaling perennial segments. We observed no notable temporal differences between 22 historical and current samples. Faxonius longidigitus, detected at few sites in low numbers, was associated with deeper waters and larger substrates.
{"title":"Stream-Dwelling Crayfishes of the North Fork of the White River Drainage of Missouri, with Additional Notes from Arkansas, USA","authors":"R. DiStefano, Erica L. Ascani, Robert B. Bratcher, Ashley N. Hrdina, Emile A. Ellingsworth, Brian K. Watson","doi":"10.5869/fc.2023.v28-1.11","DOIUrl":"https://doi.org/10.5869/fc.2023.v28-1.11","url":null,"abstract":"\u0000 Comprehensive surveys are critical to conserve and monitor crayfish communities, imperiled species, and detect crayfish invasions. The Missouri portion of the North Fork White River drainage (MONFWR) was never comprehensively surveyed, but adjacent drainage surveys suggested it could harbor species of conservation concern (SOCC). We surveyed the MONFWR to determine crayfish species richness, distributions of potential SOCC, and potential invasive species. We included recent sampling of the Arkansas portion of the drainage for a more holistic assessment of the entire drainage. We examined potential changes in crayfish communities after three decades at 22 previously sampled MONFWR locations. We also collected the first habitat association data for the endemic, Faxonius longidigitus. We detected eight taxa; none that were not known from the drainage. Faxonius neglectus chaenodactylus and Cambarus hubbsi were SOCC; F. n. chaenodactylus was common and abundant in the MONFWR; C. hubbsi was detected at only one site in Arkansas. Faxonius neglectus neglectus and Faxonius virilis were each detected only once and are likely introduced. Intermittent streams harbored diversity and abundance rivaling perennial segments. We observed no notable temporal differences between 22 historical and current samples. Faxonius longidigitus, detected at few sites in low numbers, was associated with deeper waters and larger substrates.","PeriodicalId":29940,"journal":{"name":"Freshwater Crayfish","volume":"265 29‐32","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138996961","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}
Samuel Auer, Wolfram Graf, Anne Hartmann, P. Leitner, Daniela Sint, Michale Traugott, Stefan Auer
For the stone crayfish, a threatened species listed in the Habitats Directive in Annex II and V, three monitoring methods were evaluated: hand capture by day, hand capture by night and eDNA sampling respectively. The lack of a standardized sampling method in Austria and the simultaneous obligation to monitor and report on the status of protected species requires therefore an evaluation of the different techniques. However, data show that day sampling massively favored the observation of juveniles whereas night sampling obtained higher shares of adults and males. Moreover, organic layer primarily determines the applicability of hand capturing methods. If the share of organic layer exceeded 40%, night sampling was more effective. In brooks with low amount of organic layer, no notable divergences were found. eDNA sampling provided reliable presence-absence data but cannot fully replace hand capturing methods. Data indicate that eDNA detectability depends probably on the discharge level. Below 1.5 L·s-1 eDNA detection failed but provided reliable results in sections with a higher discharge regime. In summary, all three methods are appropriate for crayfish surveillance programs, but must be applied according to the sampling design appropriate for the research questions and with an awareness of their strengths and weaknesses.
{"title":"Evaluation of Three Monitoring Methods for the Native European Crayfish Austropotamobius torrentium","authors":"Samuel Auer, Wolfram Graf, Anne Hartmann, P. Leitner, Daniela Sint, Michale Traugott, Stefan Auer","doi":"10.5869/fc.2023.v28-1.1","DOIUrl":"https://doi.org/10.5869/fc.2023.v28-1.1","url":null,"abstract":"\u0000 For the stone crayfish, a threatened species listed in the Habitats Directive in Annex II and V, three\u0000monitoring methods were evaluated: hand capture by day, hand capture by night and eDNA sampling\u0000respectively. The lack of a standardized sampling method in Austria and the simultaneous obligation to\u0000monitor and report on the status of protected species requires therefore an evaluation of the different\u0000techniques. However, data show that day sampling massively favored the observation of juveniles\u0000whereas night sampling obtained higher shares of adults and males. Moreover, organic layer primarily\u0000determines the applicability of hand capturing methods. If the share of organic layer exceeded 40%, night\u0000sampling was more effective. In brooks with low amount of organic layer, no notable divergences were\u0000found. eDNA sampling provided reliable presence-absence data but cannot fully replace hand capturing\u0000methods. Data indicate that eDNA detectability depends probably on the discharge level. Below 1.5\u0000L·s-1 eDNA detection failed but provided reliable results in sections with a higher discharge regime.\u0000In summary, all three methods are appropriate for crayfish surveillance programs, but must be applied\u0000according to the sampling design appropriate for the research questions and with an awareness of their\u0000strengths and weaknesses.","PeriodicalId":29940,"journal":{"name":"Freshwater Crayfish","volume":"118 4","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138999420","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}
Pub Date : 2023-12-15DOI: 10.5869/fc.2023.v28-1.37
Kaelyn L. Fogelman, Kayla Boyd, Hisham A. Abdelrahman, C. Figiel, James A. Stoeckel
The southeast United States is the epicenter of global crayfish biodiversity, but these species are among some of the most threatened in the world. Life history and biological trait data deficiencies, particularly of burrowing crayfish species, hampers efforts for accurately assessing imperilment rates and informing conservation efforts. Rising temperatures are a threat to aquatic ectotherms and it is important to evaluate crayfish tolerances to determine if they are at or near their upper thermal limits. We conducted dynamic temperature ramps to evaluate the temperatures at which ecological death (critical thermal maximum; CTM) and physiological death (upper thermal limit; UTL) occurred for the imperiled and narrowly endemic primary burrower Cambarus harti and three common, sympatric species C. latimanus, C. striatus, and Procambarus clarkii. All species differed in CTM with C. latimanus being the most sensitive (35.0°C), C. striatus (37.0°C) and C. harti (37.8°C) having intermediate tolerance, and P. clarkii being the most tolerant (39.0°C). The UTL of all species ranged from 39.4 – 39.8°C. We found no evidence that C. harti, a rare primary burrower, will require more restrictive acute thermal guidelines for protection compared to more common sympatric secondary burrowers.
美国东南部是全球螯虾生物多样性的中心，但这些物种却是世界上受威胁最严重的物种之一。生活史和生物特征数据的缺乏，尤其是穴居螯虾物种的缺乏，阻碍了准确评估濒危率和为保护工作提供信息的努力。温度升高对水生外温动物构成威胁，因此必须评估螯虾的耐受性，以确定它们是否处于或接近热上限。我们进行了动态温度斜坡试验，以评估濒危的狭长地带主要穴居鱼 Cambarus harti 和三种常见的同域物种 C. latimanus、C. striatus 和 Procambarus clarkii 在什么温度下会发生生态死亡（临界最高热量；CTM）和生理死亡（热上限；UTL）。所有物种的 CTM 均有差异，其中 C. latimanus 最敏感（35.0°C），C. striatus（37.0°C）和 C. harti（37.8°C）的耐受性居中，而 P. clarkii 的耐受性最强（39.0°C）。所有物种的UTL介于39.4 - 39.8°C之间。我们没有发现任何证据表明，与更常见的同域次生穴居动物相比，罕见的原生穴居动物 C. harti 需要更严格的急性热指南来保护。
{"title":"Thermal Tolerance of the Piedmont Blue Burrower Cambarus harti and Sympatric Native and Invasive Crayfish Species of the Southeastern United States","authors":"Kaelyn L. Fogelman, Kayla Boyd, Hisham A. Abdelrahman, C. Figiel, James A. Stoeckel","doi":"10.5869/fc.2023.v28-1.37","DOIUrl":"https://doi.org/10.5869/fc.2023.v28-1.37","url":null,"abstract":"\u0000 The southeast United States is the epicenter of global crayfish biodiversity, but these species are among\u0000some of the most threatened in the world. Life history and biological trait data deficiencies, particularly\u0000of burrowing crayfish species, hampers efforts for accurately assessing imperilment rates and informing\u0000conservation efforts. Rising temperatures are a threat to aquatic ectotherms and it is important to evaluate\u0000crayfish tolerances to determine if they are at or near their upper thermal limits. We conducted dynamic\u0000temperature ramps to evaluate the temperatures at which ecological death (critical thermal maximum;\u0000CTM) and physiological death (upper thermal limit; UTL) occurred for the imperiled and narrowly\u0000endemic primary burrower Cambarus harti and three common, sympatric species C. latimanus, C. striatus,\u0000and Procambarus clarkii. All species differed in CTM with C. latimanus being the most sensitive (35.0°C),\u0000C. striatus (37.0°C) and C. harti (37.8°C) having intermediate tolerance, and P. clarkii being the most\u0000tolerant (39.0°C). The UTL of all species ranged from 39.4 – 39.8°C. We found no evidence that C. harti,\u0000a rare primary burrower, will require more restrictive acute thermal guidelines for protection compared\u0000to more common sympatric secondary burrowers.","PeriodicalId":29940,"journal":{"name":"Freshwater Crayfish","volume":"86 12","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138999509","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}
Pub Date : 2023-12-15DOI: 10.5869/fc.2023.v28-1.63
Jane Devlin, D. Beresford
The Far North region of Ontario, Canada, is a wilderness area comprising 451,808 square kilometers of intact boreal forest and wetlands. Until the work presented here the most recent extensive survey for crayfish in the Far North region of Ontario was conducted in 1963. We sampled 81 locations across the Far North region of northern Ontario and the Hudson Bay Lowlands, Canada from 2009 to 2014 catching 96 specimens from 2 species: Faxonius virilis (Hagen) (92) and Faxonius propinquus (Girard) (4) These records define the northern boundary of freshwater crayfish. Unlike much of North America, species records were consistent with surveys conducted over 55 years ago. The Far North region of Ontario is facing proposed development at a scale not seen before, and our records provide necessary baseline data for ecosystem and wildlife monitoring, understanding potential future impacts, and to support sustainable resource management.
{"title":"Recent Range Records of Crayfish (Faxonius) From Far North Ontario, Canada","authors":"Jane Devlin, D. Beresford","doi":"10.5869/fc.2023.v28-1.63","DOIUrl":"https://doi.org/10.5869/fc.2023.v28-1.63","url":null,"abstract":"\u0000 The Far North region of Ontario, Canada, is a wilderness area comprising 451,808 square kilometers\u0000of intact boreal forest and wetlands. Until the work presented here the most recent extensive survey for\u0000crayfish in the Far North region of Ontario was conducted in 1963. We sampled 81 locations across\u0000the Far North region of northern Ontario and the Hudson Bay Lowlands, Canada from 2009 to 2014\u0000catching 96 specimens from 2 species: Faxonius virilis (Hagen) (92) and Faxonius propinquus (Girard)\u0000(4) These records define the northern boundary of freshwater crayfish. Unlike much of North America,\u0000species records were consistent with surveys conducted over 55 years ago. The Far North region of\u0000Ontario is facing proposed development at a scale not seen before, and our records provide necessary\u0000baseline data for ecosystem and wildlife monitoring, understanding potential future impacts, and to\u0000support sustainable resource management.","PeriodicalId":29940,"journal":{"name":"Freshwater Crayfish","volume":"34 5","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138997711","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}
Pub Date : 2023-12-15DOI: 10.5869/fc.2023.v28-1.45
Tadashi Kawai, G. Innocenti, Elena Tricarico
Museum specimens of European Astacidae, Austropotamobius fulcisianus, Austropotamobius pallipes italicus (Italian A. fulcisianus in the present study), and A. torrentium are observed, their description, diagnosis, and illustration provided. Morphometry of the type series of A. fulcisianus in Italy are analyzed and the taxonomic status of Austropotamobius crayfish in northern Italy is examined.
观察了欧洲螯虾科（Austropotamobius fulcisianus）、Austropotamobius pallipes italicus（本研究中的意大利螯虾）和 A. torrentium 的博物馆标本，提供了它们的描述、诊断和图解。分析了意大利 A. fulcisianus 模式系列的形态计量，并考察了意大利北部 Austropotamobius 小龙虾的分类地位。
{"title":"Observations on the Morphology of Museum Specimens of the European Astacidae: Austropotamobius fulcisianus (Ninni, 1886) and Austropotamobius torrentium (von Paula Schrank, 1803) (Crustacea: Decapoda)","authors":"Tadashi Kawai, G. Innocenti, Elena Tricarico","doi":"10.5869/fc.2023.v28-1.45","DOIUrl":"https://doi.org/10.5869/fc.2023.v28-1.45","url":null,"abstract":"\u0000 Museum specimens of European Astacidae, Austropotamobius fulcisianus, Austropotamobius pallipes italicus\u0000(Italian A. fulcisianus in the present study), and A. torrentium are observed, their description, diagnosis,\u0000and illustration provided. Morphometry of the type series of A. fulcisianus in Italy are analyzed and the\u0000taxonomic status of Austropotamobius crayfish in northern Italy is examined.","PeriodicalId":29940,"journal":{"name":"Freshwater Crayfish","volume":"5 8","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138999811","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}
Pub Date : 2022-12-31DOI: 10.5869/fc.2022.v27-1.17
P. Hamr, N. Verhoeff
An intensive, long-term study of the life history of O. rusticus was conducted in Fleetwood Creek, a small stream in Southern Ontario, Canada. The reproductive biology as well as molting cycle were investigated and the larval development and morphology was documented in detail for the first time in this important invasive species. Despite recent climate change effects, such as higher maximum temperatures as well as significant short term temperature fluctuations, the overall life cycle does not appear significantly different from previous studies conducted in the 1980s and 1990s but the crayfish activity appeared to be affected by temperature fluctuations associated with climate change. Mating and spawning occurred in the first week of April. The onset of mating and spawning occurred at temperatures of 9-10°C which was somewhat higher than previously reported for this species in this region of Ontario. Abdominal eggs were carried for approximately 7-weeks and larval stages remain attached to their mothers between 12 and 15 days. Free-living young were first observed in early June. Maturity is attained within the first summer, at 19-20 mm carapace length, in at least 30% of the young-of-the-year and most individuals of both sexes are mature at 25 mm carapace length. Monitoring was conducted weekly and daily during molting and spawning periods in spring 2021 and 2022, which makes this study unique with respect to most other life history field studies.
{"title":"The Life History of the Rusty Crayfish (Faxonius rusticus) in a Small Southern Ontario Stream","authors":"P. Hamr, N. Verhoeff","doi":"10.5869/fc.2022.v27-1.17","DOIUrl":"https://doi.org/10.5869/fc.2022.v27-1.17","url":null,"abstract":"\u0000 An intensive, long-term study of the life history of O. rusticus was conducted in Fleetwood Creek, a small stream in Southern Ontario, Canada. The reproductive biology as well as molting cycle were investigated and the larval development and morphology was documented in detail for the first time in this important invasive species. Despite recent climate change effects, such as higher maximum temperatures as well as significant short term temperature fluctuations, the overall life cycle does not appear significantly different from previous studies conducted in the 1980s and 1990s but the crayfish activity appeared to be affected by temperature fluctuations associated with climate change. Mating and spawning occurred in the first week of April. The onset of mating and spawning occurred at temperatures of 9-10°C which was somewhat higher than previously reported for this species in this region of Ontario. Abdominal eggs were carried for approximately 7-weeks and larval stages remain attached to their mothers between 12 and 15 days. Free-living young were first observed in early June. Maturity is attained within the first summer, at 19-20 mm carapace length, in at least 30% of the young-of-the-year and most individuals of both sexes are mature at 25 mm carapace length. Monitoring was conducted weekly and daily during molting and spawning periods in spring 2021 and 2022, which makes this study unique with respect to most other life history field studies.","PeriodicalId":29940,"journal":{"name":"Freshwater Crayfish","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47504619","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}
Pub Date : 2022-12-31DOI: 10.5869/fc.2022.v27-1.69
I. Maguire, Leona Lovrenčić, M. Temunović
Croatian freshwaters are inhabited by four native European crayfish species. One of them is the white-clawed crayfish which is distributed in the waterbodies draining to the Adriatic Sea. This species is endangered by anthropogenic pressures on its habitats, climate change and the introduction and spread of non-native invasive crayfish species and their pathogens, with several documented declines occurring in a number of populations. Consequently, it is declared endangered and protected by international and national legislation. The aim of this study was to evaluate the efficiency of the pan-European Natura 2000 network and national protected areas in conserving the white-clawed crayfish diversity in Croatia through a GIS-based approach that overlays a map of protected areas with species distribution data, also known as a gap analysis. The analysis revealed that 66% of the white-clawed crayfish populations are covered by protected areas (including Natura 2000 sites). Results of this study are useful for the evaluation of protected areas in the conservation of this key freshwater species, and for direct future management plans.
{"title":"How Well Do Protected Areas Safeguard Endangered White-Clawed Crayfish in Croatia?","authors":"I. Maguire, Leona Lovrenčić, M. Temunović","doi":"10.5869/fc.2022.v27-1.69","DOIUrl":"https://doi.org/10.5869/fc.2022.v27-1.69","url":null,"abstract":"\u0000 Croatian freshwaters are inhabited by four native European crayfish species. One of them is the white-clawed crayfish which is distributed in the waterbodies draining to the Adriatic Sea. This species is endangered by anthropogenic pressures on its habitats, climate change and the introduction and spread of non-native invasive crayfish species and their pathogens, with several documented declines occurring in a number of populations. Consequently, it is declared endangered and protected by international and national legislation. The aim of this study was to evaluate the efficiency of the pan-European Natura 2000 network and national protected areas in conserving the white-clawed crayfish diversity in Croatia through a GIS-based approach that overlays a map of protected areas with species distribution data, also known as a gap analysis. The analysis revealed that 66% of the white-clawed crayfish populations are covered by protected areas (including Natura 2000 sites). Results of this study are useful for the evaluation of protected areas in the conservation of this key freshwater species, and for direct future management plans.","PeriodicalId":29940,"journal":{"name":"Freshwater Crayfish","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45882493","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}
Freshwater crayfish rank among the most imperilled groups and play several critical roles in freshwater ecosystems, yet survey efforts remain limited throughout much of Canada and North America. Inadequate survey and monitoring efforts render our ecosystems vulnerable to the introduction and spread of harmful invasive species which can be difficult or impossible to control following establishment. During surveys targeting salamander larvae across Pelee Island, Ontario we incidentally captured crayfish and identified them to species. Three species were detected including two native species known only from collections in the 1960s (Creaserinus fodiens, Faxonius immunis) as well as the non-native White River Crayfish (Procambarus acutus) which has not been documented previously in Canada. Our oldest record of P. acutus is from 2015, and the species currently appears to be widespread and well established on Pelee Island and has also recently been recorded in Six Mile Lake on the Canadian Shield. We provide preliminary data on the aquatic habitats where each species was found on Pelee Island and strongly encourage additional monitoring efforts combined with targeted education efforts to prevent the spread of P. acutus to the Ontario mainland.
{"title":"First Records of White River Crayfish (Procambarus acutus) in Canada on Pelee Island, Ontario, with notes on other crayfish species present and their habitats","authors":"T. Hossie, P. Hamr","doi":"10.5869/fc.2022.v27-1.9","DOIUrl":"https://doi.org/10.5869/fc.2022.v27-1.9","url":null,"abstract":"\u0000 Freshwater crayfish rank among the most imperilled groups and play several critical roles in freshwater ecosystems, yet survey efforts remain limited throughout much of Canada and North America. Inadequate survey and monitoring efforts render our ecosystems vulnerable to the introduction and spread of harmful invasive species which can be difficult or impossible to control following establishment. During surveys targeting salamander larvae across Pelee Island, Ontario we incidentally captured crayfish and identified them to species. Three species were detected including two native species known only from collections in the 1960s (Creaserinus fodiens, Faxonius immunis) as well as the non-native White River Crayfish (Procambarus acutus) which has not been documented previously in Canada. Our oldest record of P. acutus is from 2015, and the species currently appears to be widespread and well established on Pelee Island and has also recently been recorded in Six Mile Lake on the Canadian Shield. We provide preliminary data on the aquatic habitats where each species was found on Pelee Island and strongly encourage additional monitoring efforts combined with targeted education efforts to prevent the spread of P. acutus to the Ontario mainland.","PeriodicalId":29940,"journal":{"name":"Freshwater Crayfish","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47267561","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}
Pub Date : 2022-12-31DOI: 10.5869/fc.2022.v27-1.49
T. Kawai, J. Patoka
Both external and internal morphological characteristics (the gastric mill and the gill on maxillipeds) of museum specimens of European Astacidae, namely Astacus astacus and Pontastacus leptodactylus, were observed and detailed illustrations and descriptions are herein provided. Several morphological variations in external morphology were detected, and the characters to discriminate between Astacus and Pontastacus have been used to update the diagnoses of these two genera.
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