M. Emery-Wetherell, C. Mathew, Cameron Church, Ellie Dellard, E. Davis, J. Roering
ABSTRACT Many species of terrestrial mollusks are small and difficult to find, with poorly known ranges and habitat preferences. Because desiccation is a primary cause of mortality for many terrestrial mollusks, incorporating wetness as a habitat variable may improve survey results for different species. We compared presence and abundance data from terrestrial mollusk surveys in Tillamook Resource Area to two measures of relative wetness: topographic wetness index (TWI) and geomorphic features (landslides, debris-flow channels, etc.). Hurdle Model regression revealed a positive correlation between increased TWI and likelihood of presence or abundance for four species, and a negative correlation for six species. Overall species diversity and total mollusk count were negatively correlated with increased TWI, but the effect size was small (p = 0.02, R2= -0.03). Our Kruskal-Wallis Analysis of Variance of TWI between species was significant (p < 0.001), indicating terrestrial mollusks occupy significantly different wetness regimes – but this relationship was driven entirely by the wetness specialization of Hemphillia glandulosa. Our chi-square analysis of topographic features found significant preferences of different species for different topographic types, which correlated loosely but not precisely to the preferences indicated by TWI. These results show that altering current terrestrial mollusk survey protocol to include geomorphic features, which are simpler and less time-intensive than calculating TWI, would increase detection likelihood of certain species, including Hemphillia glandulosa, a species protected under the Survey and Manage guidelines of the Northwest Forest Plan.
{"title":"The Correlation of Topographically-Derived Relative Wetness with Terrestrial Mollusk Presence and Abundance","authors":"M. Emery-Wetherell, C. Mathew, Cameron Church, Ellie Dellard, E. Davis, J. Roering","doi":"10.4002/040.062.0203","DOIUrl":"https://doi.org/10.4002/040.062.0203","url":null,"abstract":"ABSTRACT Many species of terrestrial mollusks are small and difficult to find, with poorly known ranges and habitat preferences. Because desiccation is a primary cause of mortality for many terrestrial mollusks, incorporating wetness as a habitat variable may improve survey results for different species. We compared presence and abundance data from terrestrial mollusk surveys in Tillamook Resource Area to two measures of relative wetness: topographic wetness index (TWI) and geomorphic features (landslides, debris-flow channels, etc.). Hurdle Model regression revealed a positive correlation between increased TWI and likelihood of presence or abundance for four species, and a negative correlation for six species. Overall species diversity and total mollusk count were negatively correlated with increased TWI, but the effect size was small (p = 0.02, R2= -0.03). Our Kruskal-Wallis Analysis of Variance of TWI between species was significant (p < 0.001), indicating terrestrial mollusks occupy significantly different wetness regimes – but this relationship was driven entirely by the wetness specialization of Hemphillia glandulosa. Our chi-square analysis of topographic features found significant preferences of different species for different topographic types, which correlated loosely but not precisely to the preferences indicated by TWI. These results show that altering current terrestrial mollusk survey protocol to include geomorphic features, which are simpler and less time-intensive than calculating TWI, would increase detection likelihood of certain species, including Hemphillia glandulosa, a species protected under the Survey and Manage guidelines of the Northwest Forest Plan.","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":"62 1","pages":"225 - 236"},"PeriodicalIF":1.3,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47505806","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}
ABSTRACT Freshwater bivalves in the family Unionidae are one of the most endangered groups of animals in North America. In Texas, where over 60% of unionids are rare or very rare, 15 species have been added to the state's list of threatened species, and 10 are under consideration for federal listing. Due to insufficient survey efforts in the past decades, however, primary data on current distribution and habitat requirement for most of these rare species are lacking, thus challenging their protection and management. Although the species are listed as valid, there was no genetic confirmation to test for the possibility of ecophenotypes, which complicates conservation efforts. In this paper, we present genetic and distributional data for two rare Texas species, Truncilla macrodon and Truncilla cognata, and we suggest appropriate conservation measures. Tests of genetic affinities of these species using three gene regions, cox1, nad1 and ITS1, supported recognition of T. cognata and T. macrodon as full species. Analysis of historic and current species distribution showed that both these regional endemics are particularly vulnerable, and their distribution range has been reduced in the last 80 years.
{"title":"Status of Rare Endemic Species: Molecular Phylogeny, Distribution and Conservation of Freshwater Molluscs Truncilla macrodon and Truncilla cognata in Texas","authors":"L. Burlakova, D. Campbell, A. Karatayev","doi":"10.4002/040.062.0210","DOIUrl":"https://doi.org/10.4002/040.062.0210","url":null,"abstract":"ABSTRACT Freshwater bivalves in the family Unionidae are one of the most endangered groups of animals in North America. In Texas, where over 60% of unionids are rare or very rare, 15 species have been added to the state's list of threatened species, and 10 are under consideration for federal listing. Due to insufficient survey efforts in the past decades, however, primary data on current distribution and habitat requirement for most of these rare species are lacking, thus challenging their protection and management. Although the species are listed as valid, there was no genetic confirmation to test for the possibility of ecophenotypes, which complicates conservation efforts. In this paper, we present genetic and distributional data for two rare Texas species, Truncilla macrodon and Truncilla cognata, and we suggest appropriate conservation measures. Tests of genetic affinities of these species using three gene regions, cox1, nad1 and ITS1, supported recognition of T. cognata and T. macrodon as full species. Analysis of historic and current species distribution showed that both these regional endemics are particularly vulnerable, and their distribution range has been reduced in the last 80 years.","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":"62 1","pages":"345 - 363"},"PeriodicalIF":1.3,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42100055","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}
ABSTRACT This paper provides a biography, bibliography and taxonomic catalog for John Clarkson Jay (1808–1891), emphasizing his malacological research based upon his sizable collection and his contributions to the growth and expansion of the New York Lyceum of Natural History, the predecessor to the American Museum of Natural History. Jay described one new genus and 49 new species of molluscs; type specimens are known for 34 of them. He also published but did not describe 76 manuscript names mostly from material collected by Nuttall, of which 28 were made available by later authors (mostly by either Reeve or Carpenter). His collection and sizable library of rare books formed the nucleus of the malacological collection and the rare book library of the American Museum of Natural History. This paper summarizes his life, the growth of his collection, his publications, his new taxa, and his broader role in 19th-century New York professional life.
{"title":"John Clarkson Jay (1808–1891): His Life and Malacological Contributions","authors":"A. Kabat, E. Coan","doi":"10.4002/040.062.0206","DOIUrl":"https://doi.org/10.4002/040.062.0206","url":null,"abstract":"ABSTRACT This paper provides a biography, bibliography and taxonomic catalog for John Clarkson Jay (1808–1891), emphasizing his malacological research based upon his sizable collection and his contributions to the growth and expansion of the New York Lyceum of Natural History, the predecessor to the American Museum of Natural History. Jay described one new genus and 49 new species of molluscs; type specimens are known for 34 of them. He also published but did not describe 76 manuscript names mostly from material collected by Nuttall, of which 28 were made available by later authors (mostly by either Reeve or Carpenter). His collection and sizable library of rare books formed the nucleus of the malacological collection and the rare book library of the American Museum of Natural History. This paper summarizes his life, the growth of his collection, his publications, his new taxa, and his broader role in 19th-century New York professional life.","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":"62 1","pages":"257 - 309"},"PeriodicalIF":1.3,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42526499","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}
Victoria Araiza-Gómez, Zaidett Barrientos-Llosa, E. A. Ruíz, G. Zúñiga
ABSTRACT We describe a new helicoidean semi-slug based on morphological and molecular evidence. The new species belongs to the genus Bunnya and is described from a small agricultural area in Zinacantepec, San Juan de las Huertas, México. The genus Bunnya is externally similar to Xanthonyx, another Helicoidea genus; both genera have similar shell and body form, and both have a tail horn. Internally, Bunnya is similar to Humboldtiana, since both have dart-sacs (3 in Bunnya, 3−4 in Humboldtiana) surrounding the vagina, two dart-bulbs associated with each dart sac, and a gland number similar to the dart-sacs number. Four adult specimens of Bunnya metli n. sp. were dissected and compared with the two described species: B. bernardinae from Cuajimalpa, México City, and B. naranjoe from Sierra de Manantlan, Jalisco. Bunnya metli n. sp. is characterized by: very closely-spaced radial riblets (about 23 per mm) crossed by fine spiral wavy threads on the embryonic whorls; unfused glands inserted on the vagina above the dart-sacs and only one dart per sac; a short, swollen penis with a large spherical verge about half the penis size; an elongated bursa copulatrix with a slight constriction in the middle; a long bursa copulatrix duct; and dart sacs with a muscular pad within the vaginal lumen, surrounding the basal part of the genitalia. We performed a phylogenetic analyses using data from fragments of 16S rRNA mtDNA and 28S rRNA genes from one of the collected specimens, as well as other helicoidean sequences from GenBank. Our analyses support the membership of Bunnya metli n. sp. in Xanthonychidae. This suggests that the taxonomic position of Bunnya in Humboldtianidae or Xanthonychidae warrants reevaluation.
{"title":"A New Species of the Genus Bunnya H. B. Baker, 1942 (Helicoidea) from MÉXico","authors":"Victoria Araiza-Gómez, Zaidett Barrientos-Llosa, E. A. Ruíz, G. Zúñiga","doi":"10.4002/040.062.0204","DOIUrl":"https://doi.org/10.4002/040.062.0204","url":null,"abstract":"ABSTRACT We describe a new helicoidean semi-slug based on morphological and molecular evidence. The new species belongs to the genus Bunnya and is described from a small agricultural area in Zinacantepec, San Juan de las Huertas, México. The genus Bunnya is externally similar to Xanthonyx, another Helicoidea genus; both genera have similar shell and body form, and both have a tail horn. Internally, Bunnya is similar to Humboldtiana, since both have dart-sacs (3 in Bunnya, 3−4 in Humboldtiana) surrounding the vagina, two dart-bulbs associated with each dart sac, and a gland number similar to the dart-sacs number. Four adult specimens of Bunnya metli n. sp. were dissected and compared with the two described species: B. bernardinae from Cuajimalpa, México City, and B. naranjoe from Sierra de Manantlan, Jalisco. Bunnya metli n. sp. is characterized by: very closely-spaced radial riblets (about 23 per mm) crossed by fine spiral wavy threads on the embryonic whorls; unfused glands inserted on the vagina above the dart-sacs and only one dart per sac; a short, swollen penis with a large spherical verge about half the penis size; an elongated bursa copulatrix with a slight constriction in the middle; a long bursa copulatrix duct; and dart sacs with a muscular pad within the vaginal lumen, surrounding the basal part of the genitalia. We performed a phylogenetic analyses using data from fragments of 16S rRNA mtDNA and 28S rRNA genes from one of the collected specimens, as well as other helicoidean sequences from GenBank. Our analyses support the membership of Bunnya metli n. sp. in Xanthonychidae. This suggests that the taxonomic position of Bunnya in Humboldtianidae or Xanthonychidae warrants reevaluation.","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":"62 1","pages":"237 - 246"},"PeriodicalIF":1.3,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45910125","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}
ABSTRACT The date mussel Lithophaga lithophaga is a chemical borer that uses pallial gland secretions to bore holes in the substrate. Calcium-binding proteins are generally considered to be responsible for the chemical dissolution of the calcareous substrate. The aim of this study was to investigate the relative expression of five candidate genes – ANXB9, SCP, CALR, PLA2 and V-ATPase – in four different tissues, with the hypothesis that the expression profile of the candidate genes in the pallial gland would differ from the rest. The results from gene expression analysis revealed that CALR, PLA2 and SCP were up-regulated in the pallial gland. Two of the candidate genes (ANXB9 and V-ATPase) had the same expression profile in all four investigated tissues, indicating that they are not directly involved in the chemical boring mechanism. The results of this study shed light on the genetic background of the chemical boring mechanism in date mussel. This set of candidate genes could be used in future research studies of chemical boring in the date mussel and other marine or freshwater borers.
{"title":"Candidate Calcium-Binding Genes for Chemical Boring in the Date Mussel Lithophaga lithophaga","authors":"U. Sivka","doi":"10.4002/040.062.0208","DOIUrl":"https://doi.org/10.4002/040.062.0208","url":null,"abstract":"ABSTRACT The date mussel Lithophaga lithophaga is a chemical borer that uses pallial gland secretions to bore holes in the substrate. Calcium-binding proteins are generally considered to be responsible for the chemical dissolution of the calcareous substrate. The aim of this study was to investigate the relative expression of five candidate genes – ANXB9, SCP, CALR, PLA2 and V-ATPase – in four different tissues, with the hypothesis that the expression profile of the candidate genes in the pallial gland would differ from the rest. The results from gene expression analysis revealed that CALR, PLA2 and SCP were up-regulated in the pallial gland. Two of the candidate genes (ANXB9 and V-ATPase) had the same expression profile in all four investigated tissues, indicating that they are not directly involved in the chemical boring mechanism. The results of this study shed light on the genetic background of the chemical boring mechanism in date mussel. This set of candidate genes could be used in future research studies of chemical boring in the date mussel and other marine or freshwater borers.","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":"62 1","pages":"319 - 328"},"PeriodicalIF":1.3,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44174871","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}
ABSTRACT No introduced marine pests, also known as invasive marine species, were detected in a dry season survey in August 1998 in Darwin Harbour, Northern Territory, Australia. A postwet-season survey in March 1999 found extensive populations of the false mussel Mytilopsis sallei (Récluz, 1849) in the Cullen Bay Marina. An environmental emergency was declared and M. sallei were eliminated. The present paper examines possible reasons for the failure of M. sallei to establish outside Cullen Bay. Mytilopsis sallei is a fresh/brackish water species that naturally lives in low salinities. It is hypothesized that the osmotic shock of rapid movement from low salinity water in Cullen Bay to much higher salinities outside the marina killed the veligers when they were discharged through the entrance lock when it was opened to allow vessel movements. If it entered the harbour, M. sallei could possibly have established in low salinity water in the arms leading into the harbour and possibly have spread in northern Australia.
{"title":"Environmental Emergency: Why Did the False Mussel Mytilopsis sallei Not Invade Darwin Harbour, Australia?","authors":"F. Wells","doi":"10.4002/040.062.0205","DOIUrl":"https://doi.org/10.4002/040.062.0205","url":null,"abstract":"ABSTRACT No introduced marine pests, also known as invasive marine species, were detected in a dry season survey in August 1998 in Darwin Harbour, Northern Territory, Australia. A postwet-season survey in March 1999 found extensive populations of the false mussel Mytilopsis sallei (Récluz, 1849) in the Cullen Bay Marina. An environmental emergency was declared and M. sallei were eliminated. The present paper examines possible reasons for the failure of M. sallei to establish outside Cullen Bay. Mytilopsis sallei is a fresh/brackish water species that naturally lives in low salinities. It is hypothesized that the osmotic shock of rapid movement from low salinity water in Cullen Bay to much higher salinities outside the marina killed the veligers when they were discharged through the entrance lock when it was opened to allow vessel movements. If it entered the harbour, M. sallei could possibly have established in low salinity water in the arms leading into the harbour and possibly have spread in northern Australia.","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":"62 1","pages":"247 - 256"},"PeriodicalIF":1.3,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43409581","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}
ABSTRACT The Oriental region is among the world's biologically most diverse regions, but also among the most biotically threatened, especially with regard to freshwater biota. The Cerithioidea comprise several families and are a major component of the freshwater gastropod fauna in the Oriental region. Among these, the Paludomidae include numerous taxa mostly described in the 19thcentury that are in many cases badly in need of revision. As an initial step towards a better understanding of the evolutionary systematics of the family, we here review the genus-group taxonomy and nomenclature of Asian Paludomidae. We show that Paludomus Swainson, 1840, Philopotamis Layard, 1855, Ganga Layard, 1855, and Odontochasma Tomlin, 1930, are available names for morphology-based genus-group taxa of Asian Paludomidae. By selection of Melania modicella I. Lea & H. C. Lea, 1851, as type species of Rivulina I. Lea & H. C. Lea, 1851, and by the designation of a neotype for Paludomus (Hemimitra) retusa Swainson, 1840, Rivulina and Hemimitra Swainson, 1840, can both be regarded as synonyms of Paludomus s. str. By selection of Paludomus sulcatus Reeve, 1847, as its type species, Heteropoma Benson, 1856, becomes an objective junior synonym of Philopotamis Layard, 1855. Furthermore, we show that the type species of Tanalia Gray, 1847, which has often been used for a subdivision of Paludomus or as a distinct genus, belongs to the Neritidae and that Odontochasma Tomlin, 1930, has been validly proposed as a replacement name for the preoccupied name Stomatodon Benson, 1862. Finally, we revise Paludomus (Odontochasma) stomatodon Benson, 1862, on the basis of available type material, describe its radula for the first time, and compare it with published data on radulae of other Asian paludomids. Taxonomic redundancy in the genus-group in Asian Paludomidae is estimated to be 50% and may be as high as 88% depending on taxonomic opinion.
{"title":"Nomenclature of Genus-Group Names of Recent Asian Paludomidae (Gastropoda: Cerithioidea), with a Revision of Paludomus (Odontochasma) Stomatodon (Benson, 1862) from the Western Ghats, India","authors":"M. Neiber, M. Glaubrecht","doi":"10.4002/040.062.0209","DOIUrl":"https://doi.org/10.4002/040.062.0209","url":null,"abstract":"ABSTRACT The Oriental region is among the world's biologically most diverse regions, but also among the most biotically threatened, especially with regard to freshwater biota. The Cerithioidea comprise several families and are a major component of the freshwater gastropod fauna in the Oriental region. Among these, the Paludomidae include numerous taxa mostly described in the 19thcentury that are in many cases badly in need of revision. As an initial step towards a better understanding of the evolutionary systematics of the family, we here review the genus-group taxonomy and nomenclature of Asian Paludomidae. We show that Paludomus Swainson, 1840, Philopotamis Layard, 1855, Ganga Layard, 1855, and Odontochasma Tomlin, 1930, are available names for morphology-based genus-group taxa of Asian Paludomidae. By selection of Melania modicella I. Lea & H. C. Lea, 1851, as type species of Rivulina I. Lea & H. C. Lea, 1851, and by the designation of a neotype for Paludomus (Hemimitra) retusa Swainson, 1840, Rivulina and Hemimitra Swainson, 1840, can both be regarded as synonyms of Paludomus s. str. By selection of Paludomus sulcatus Reeve, 1847, as its type species, Heteropoma Benson, 1856, becomes an objective junior synonym of Philopotamis Layard, 1855. Furthermore, we show that the type species of Tanalia Gray, 1847, which has often been used for a subdivision of Paludomus or as a distinct genus, belongs to the Neritidae and that Odontochasma Tomlin, 1930, has been validly proposed as a replacement name for the preoccupied name Stomatodon Benson, 1862. Finally, we revise Paludomus (Odontochasma) stomatodon Benson, 1862, on the basis of available type material, describe its radula for the first time, and compare it with published data on radulae of other Asian paludomids. Taxonomic redundancy in the genus-group in Asian Paludomidae is estimated to be 50% and may be as high as 88% depending on taxonomic opinion.","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":"62 1","pages":"329 - 344"},"PeriodicalIF":1.3,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48405509","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}
Increasing traffic and trade, the modification of landscapes by humans, and climate change facilitate the dispersal of certain species that are adapted to anthropogenic habitats. When species’ natural dispersal limitations are overridden by human-mediated dispersal, the composition of communities can be determined by the prevailing climate, rather than reflecting biogeographic realms, as has been shown for terrestrial snails (Capinha et al., 2015). The size of a species’ native range affects the probability that it will become invasive (Pyšek et al., 2009). Thus, endemic species with small geographic ranges rarely become invasive. Here we report a new record of the Carpathian blue slug Bielzia coerulans (Bielz, 1851) (Gastropoda: Limacidae) from the Bavarian Forest in Germany, which together with other records might indicate an ongoing expansion of this characteristic representative of the Carpathian fauna westward. The discovery of Bielzia coerulans was a fortuitous result of entomological excursions in the Bavarian Forest in southern Germany. The identification of the species was based on the external morphology (Fig. 1) in accordance with characteristics given by Wiktor (1989) and Wiese & von Glasow (2013). A single adult specimen of the Carpathian blue slug Bielzia coerulans (Fig. 1) was discovered under a large stone in the nature reserve “Pfahl bei der Ruine Weißenstein” about 800 m southeast of Regen-Weißenstein (48°56’38.87”N, 13°09’29.16”E), at 710 m a.s.l., in the Bavarian Forest in Germany on 9 August 2017 by the second author. The specimen was immediately identified by its characteristic blue colour and recorded. Further searching did not result in the discovery of additional specimens. MALACOLOGIA, 2019, 62(2): 373–375
交通和贸易的增加、人类对景观的改变以及气候变化促进了某些适应人类栖息地的物种的扩散。当物种的自然扩散限制被人类介导的扩散所覆盖时，群落的组成可以由当时的气候决定，而不是像陆地蜗牛那样反映生物地理领域（Capinha等人，2015）。一个物种的原生范围大小会影响其入侵的可能性（Pyšek等人，2009年）。因此，地理范围较小的特有物种很少会成为入侵物种。在这里，我们报道了来自德国巴伐利亚森林的喀尔巴阡蓝蛞蝓Bielzia coerulans（Bielz，1851）（腹足目：Limacidae）的新记录，这与其他记录一起可能表明喀尔巴提亚动物群的这一特征代表正在向西扩展。在德国南部巴伐利亚森林进行昆虫学考察后，偶然发现了科氏Bielzia coerulans。该物种的鉴定基于外部形态（图1），符合Wiktor（1989）和Wiese&von Glasow（2013）给出的特征。2017年8月9日，第二作者在德国巴伐利亚森林的Regen Weißenstein东南约800米处（北纬48°56'38.87“，东经13°09'29.16”）的自然保护区“Pfahl bei der Ruine Weiłensstein”的一块大石头下发现了喀尔巴阡蓝蛞蝓Bielzia coerulans的一个成年标本（图1）。该标本立即通过其特有的蓝色进行了鉴定并进行了记录。进一步的搜索没有发现更多的标本。孔雀学，2019，62（2）：373–375
{"title":"Ongoing Westward Expansion of the Carpathian Blue Slug Bielzia coerulans into Central Europe","authors":"B. Hausdorf, M. Würmli","doi":"10.4002/040.062.0212","DOIUrl":"https://doi.org/10.4002/040.062.0212","url":null,"abstract":"Increasing traffic and trade, the modification of landscapes by humans, and climate change facilitate the dispersal of certain species that are adapted to anthropogenic habitats. When species’ natural dispersal limitations are overridden by human-mediated dispersal, the composition of communities can be determined by the prevailing climate, rather than reflecting biogeographic realms, as has been shown for terrestrial snails (Capinha et al., 2015). The size of a species’ native range affects the probability that it will become invasive (Pyšek et al., 2009). Thus, endemic species with small geographic ranges rarely become invasive. Here we report a new record of the Carpathian blue slug Bielzia coerulans (Bielz, 1851) (Gastropoda: Limacidae) from the Bavarian Forest in Germany, which together with other records might indicate an ongoing expansion of this characteristic representative of the Carpathian fauna westward. The discovery of Bielzia coerulans was a fortuitous result of entomological excursions in the Bavarian Forest in southern Germany. The identification of the species was based on the external morphology (Fig. 1) in accordance with characteristics given by Wiktor (1989) and Wiese & von Glasow (2013). A single adult specimen of the Carpathian blue slug Bielzia coerulans (Fig. 1) was discovered under a large stone in the nature reserve “Pfahl bei der Ruine Weißenstein” about 800 m southeast of Regen-Weißenstein (48°56’38.87”N, 13°09’29.16”E), at 710 m a.s.l., in the Bavarian Forest in Germany on 9 August 2017 by the second author. The specimen was immediately identified by its characteristic blue colour and recorded. Further searching did not result in the discovery of additional specimens. MALACOLOGIA, 2019, 62(2): 373–375","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":"62 1","pages":"373 - 375"},"PeriodicalIF":1.3,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41637372","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}
N. Tamburi, S. Burela, Martín A. Carrizo, P. Martín
ABSTRACT Snails exhibit a primary left-right asymmetry that appears during the first cleavages of the eggs, and a secondary asymmetry, related to the coiling of the shell. Most species are constituted by either dextral or sinistral morphs (enantiomorphs) while individuals with reversed primary asymmetry are extremely rare. Freshwater snails of the family Ampullariidae are normally dextral enantiomorphs with planispiral, hyperstrophic or orthostrophic shells. Pomacea canaliculata, a well-studied species because of its invasive status, shows dextral primary asymmetry and orthostrophic growth that results in clock-wise shells. Despite the great number of studies focused on P. canaliculata, only two specimens with reversed asymmetry have been hitherto reported. Here we report the finding of two live snails and three empty shells of P. canaliculata with anti-clockwise coiling that appeared in two populations from the southern Pampas, Argentina. Both anti-clockwise live snails were males that attempted to copulate with clock-wise females in the laboratory but failed to inseminate them. The apex of anti-clockwise shells and the anatomy of the snails revealed that the reversal of coiling was due to an orthostrophic development of sinistral enantiomorphs. Morphological analysis performed through geometric morphometrics did not find other differences with clock-wise snails other than coiling direction. We conclude that these anti-clockwise snails are probably engendered, as in other snails species, when the mother is a recessive homozygote for reversing alleles that show delayed maternal inheritance. The chances of establishment of populations with dimorphic asymmetry are very low because of the reproductive disadvantages of anti-clockwise individuals.
{"title":"Through the Looking-Glass: Shell Morphology, Anatomy and Mating Behavior of Reversed Pomacea Canaliculata (Caenogastropoda, Ampullariidae)","authors":"N. Tamburi, S. Burela, Martín A. Carrizo, P. Martín","doi":"10.4002/040.062.0201","DOIUrl":"https://doi.org/10.4002/040.062.0201","url":null,"abstract":"ABSTRACT Snails exhibit a primary left-right asymmetry that appears during the first cleavages of the eggs, and a secondary asymmetry, related to the coiling of the shell. Most species are constituted by either dextral or sinistral morphs (enantiomorphs) while individuals with reversed primary asymmetry are extremely rare. Freshwater snails of the family Ampullariidae are normally dextral enantiomorphs with planispiral, hyperstrophic or orthostrophic shells. Pomacea canaliculata, a well-studied species because of its invasive status, shows dextral primary asymmetry and orthostrophic growth that results in clock-wise shells. Despite the great number of studies focused on P. canaliculata, only two specimens with reversed asymmetry have been hitherto reported. Here we report the finding of two live snails and three empty shells of P. canaliculata with anti-clockwise coiling that appeared in two populations from the southern Pampas, Argentina. Both anti-clockwise live snails were males that attempted to copulate with clock-wise females in the laboratory but failed to inseminate them. The apex of anti-clockwise shells and the anatomy of the snails revealed that the reversal of coiling was due to an orthostrophic development of sinistral enantiomorphs. Morphological analysis performed through geometric morphometrics did not find other differences with clock-wise snails other than coiling direction. We conclude that these anti-clockwise snails are probably engendered, as in other snails species, when the mother is a recessive homozygote for reversing alleles that show delayed maternal inheritance. The chances of establishment of populations with dimorphic asymmetry are very low because of the reproductive disadvantages of anti-clockwise individuals.","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":"62 1","pages":"205 - 214"},"PeriodicalIF":1.3,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42037226","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}
M. Villalejo-Fuerte, M. A. Camacho-Mondragón, B. Ceballos-Vázquez, E. O. López-Villegas, Esther Uría-Galicia, M. Arellano-Martínez
ABSTRACT The entire spermatogenesis process and the presence of accessory cells in sperm development in Spondylus princeps Broderip, 1833, and S. calcifer Carpenter, 1857, were described for the first time. Spermatogenesis in both species showed similar anatomical and ultrastructural features. The testis contained amoeboid somatic cells inside the acini, frequently associated with developing gametes. Overall, spermatogenesis followed the typical pattern reported for other bivalve species, except for a few specific details. In S. princeps, intercellular bridges between spermatogonia, as well as one spermatocyte with seven mitochondria were observed. Both species had mature sperm of the ect-aquasperm type, consisting of a head, which contains a spherical-pyriform nucleus and a conical acrosome bounded by two regions of different density, four spherical mitochondria and two centrioles in the middle piece; the flagellum showed a standard 9 + 2 microtubule arrangement.
本文首次描述了1833年和1857年的Spondylus princeps Broderip和S. calcifer Carpenter的精子发育过程中的整个精子发生过程和辅助细胞的存在。两个物种的精子发生具有相似的解剖和超微结构特征。睾丸在腺泡内含有变形虫体细胞，通常与发育中的配子有关。总的来说，精子发生遵循了其他双壳类物种的典型模式，除了一些特定的细节。在太子参中，观察到精原细胞之间的细胞间桥，以及一个精母细胞与七个线粒体。这两种植物都有异水精型的成熟精子，包括一个头部，其中包含一个球形梨形核和一个圆锥形顶体，顶体由两个不同密度的区域包围，四个球形线粒体和中间的两个中心粒;鞭毛呈标准的9 + 2微管排列。
{"title":"Ultrastructure of Sperm Development and Mature Sperm Morphology in Spondylus calcifer and S. Princeps (Bivalvia: Spondylidae)","authors":"M. Villalejo-Fuerte, M. A. Camacho-Mondragón, B. Ceballos-Vázquez, E. O. López-Villegas, Esther Uría-Galicia, M. Arellano-Martínez","doi":"10.4002/040.062.0102","DOIUrl":"https://doi.org/10.4002/040.062.0102","url":null,"abstract":"ABSTRACT The entire spermatogenesis process and the presence of accessory cells in sperm development in Spondylus princeps Broderip, 1833, and S. calcifer Carpenter, 1857, were described for the first time. Spermatogenesis in both species showed similar anatomical and ultrastructural features. The testis contained amoeboid somatic cells inside the acini, frequently associated with developing gametes. Overall, spermatogenesis followed the typical pattern reported for other bivalve species, except for a few specific details. In S. princeps, intercellular bridges between spermatogonia, as well as one spermatocyte with seven mitochondria were observed. Both species had mature sperm of the ect-aquasperm type, consisting of a head, which contains a spherical-pyriform nucleus and a conical acrosome bounded by two regions of different density, four spherical mitochondria and two centrioles in the middle piece; the flagellum showed a standard 9 + 2 microtubule arrangement.","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":"62 1","pages":"1 - 10"},"PeriodicalIF":1.3,"publicationDate":"2018-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4002/040.062.0102","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41725711","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：