Abstract: A growing use of natural history collections is documenting changes in species distributions, morphology, phenology and genetics during historical times. Until the 20th century, however, collecting dates were not routinely recorded in collections, making it difficult to determine the time course of biotic changes. Various forms of proxy data can constrain when a particular sample might have been collected. The date of cataloguing puts an upper limit on potential collecting dates, as do dates of death of agents such as collectors, donors, and other previous owners, and dates of birth and activity of collectors give a lower limit. Archival material such as field notes and acquisition records can also provide constraints. Information in such sources should be captured in standardized biographical databases to allow automated bounds on collecting dates to be applied via fields in collection databases. Mollusks are among the best sampled metazoans, so they can serve to test the effectiveness of using biographical data to constrain collecting dates. A random sample of records in the ANSP malacology database that lack date of collection shows that when an agent is known, date of death information improves on date of cataloguing as a constraint on collecting date for 41% of records. Overall, including records that lacked agent information, 38% had improvement. If further historical information such as dates of travel, residence, employment and other affiliations were included in biographical databases, additional improvement on these bounds could be obtained. Collection databases need appropriate data structures for provenance information to track the chain of ownership of specimens more rigorously, and to allow cleaner interface with biographical databases. A survey of other large mollusk collections in the United States suggests that a similar level of improvement could be obtained more generally, affecting millions of specimens. If this result could be extended to other disciplines, a substantially increased proportion of specimens in natural history collections would be accessible for studies of biotic change. Interoperability with genealogical databases could accelerate addition of provenance data to natural history databases.
{"title":"Improving Provenance Data in Natural History Collection Databases","authors":"G. Rosenberg, M. Khoo","doi":"10.4003/006.036.0203","DOIUrl":"https://doi.org/10.4003/006.036.0203","url":null,"abstract":"Abstract: A growing use of natural history collections is documenting changes in species distributions, morphology, phenology and genetics during historical times. Until the 20th century, however, collecting dates were not routinely recorded in collections, making it difficult to determine the time course of biotic changes. Various forms of proxy data can constrain when a particular sample might have been collected. The date of cataloguing puts an upper limit on potential collecting dates, as do dates of death of agents such as collectors, donors, and other previous owners, and dates of birth and activity of collectors give a lower limit. Archival material such as field notes and acquisition records can also provide constraints. Information in such sources should be captured in standardized biographical databases to allow automated bounds on collecting dates to be applied via fields in collection databases. Mollusks are among the best sampled metazoans, so they can serve to test the effectiveness of using biographical data to constrain collecting dates. A random sample of records in the ANSP malacology database that lack date of collection shows that when an agent is known, date of death information improves on date of cataloguing as a constraint on collecting date for 41% of records. Overall, including records that lacked agent information, 38% had improvement. If further historical information such as dates of travel, residence, employment and other affiliations were included in biographical databases, additional improvement on these bounds could be obtained. Collection databases need appropriate data structures for provenance information to track the chain of ownership of specimens more rigorously, and to allow cleaner interface with biographical databases. A survey of other large mollusk collections in the United States suggests that a similar level of improvement could be obtained more generally, affecting millions of specimens. If this result could be extended to other disciplines, a substantially increased proportion of specimens in natural history collections would be accessible for studies of biotic change. Interoperability with genealogical databases could accelerate addition of provenance data to natural history databases.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"36 1","pages":"215 - 231"},"PeriodicalIF":0.5,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49482061","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 radular apparatus of Biomphalaria occidentalis Paraense, 1981, Biomphalaria oligoza Paraense, 1971, Biomphalaria peregrina (d'Orbigny, 1835), Biomphalaria schrammi (Crosse, 1864) and Biomphalaria tenagophila (d'Orbigny, 1835) from the Metropolitan Region of São Paulo, Brazil were analyzed from Scanning Electron Microscope (SEM) micrographs. The data support the usage of characters of central, lateral and intermediate teeth in the species identification of Biomphalaria. The use of SEM provided additional quantitative and structural details to radula descriptions, which are extremely important for elucidating the taxonomy of Biomphalaria species.
{"title":"Radula and Mandible of Biomphalaria (Planorbidae) of São Paulo, Brazil","authors":"T. J. Rossignoli, R. Tuan, F. P. Ohlweiler","doi":"10.4003/006.036.0102","DOIUrl":"https://doi.org/10.4003/006.036.0102","url":null,"abstract":"Abstract: The radular apparatus of Biomphalaria occidentalis Paraense, 1981, Biomphalaria oligoza Paraense, 1971, Biomphalaria peregrina (d'Orbigny, 1835), Biomphalaria schrammi (Crosse, 1864) and Biomphalaria tenagophila (d'Orbigny, 1835) from the Metropolitan Region of São Paulo, Brazil were analyzed from Scanning Electron Microscope (SEM) micrographs. The data support the usage of characters of central, lateral and intermediate teeth in the species identification of Biomphalaria. The use of SEM provided additional quantitative and structural details to radula descriptions, which are extremely important for elucidating the taxonomy of Biomphalaria species.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"36 1","pages":"125 - 139"},"PeriodicalIF":0.5,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.036.0102","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45750213","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}
R. A. Krebs, Trevor J. Prescott, W. B. Clapham, D. Klarer
Abstract: Where a stream enters a large lake, the mouth represents a transitional environment that is neither truly lotic nor lentic in nature and therefore is likely to affect the fauna present. Theory on habitat area and stream size predicts that species richness will increase farther downstream as watershed size increases, but as stream gradient and thus flow rate declines, stream mouths present a different and understudied habitat. Freshwater mussels in the family Unionidae are in decline, and therefore understanding how they respond across diverse habitats is also critical. We sampled mussel assemblages from 2010 to 2012 in the lower reaches of twelve small tributaries and two large embayments of the western and central basins of Lake Erie, where watershed size ranged from 10 to 4000 km2. These watersheds were assessed for land use by remote sensing and for basic water chemistry and the composition of their benthos by standard protocols. Evidence of native unionid mussels occurred in all watersheds, with 14 species found alive, which make up 75% of mussel species still present throughout Lake Erie. A species-area relationship occurred, although the effect was weaker than that present for flowing streams in the region. Additionally, the habitat and corresponding assemblages were characterized as depositional in nature, which logically follow high agricultural land use and corresponding high levels of turbidity and the proportion of silt and clay. Therefore, the lake environment influenced mussel assemblages, yet these conditions appear to limit dreissenid mussels in river mouths.
{"title":"Freshwater Mussel Assemblages at the Lotic-Lentic Interface along Lake Erie","authors":"R. A. Krebs, Trevor J. Prescott, W. B. Clapham, D. Klarer","doi":"10.4003/006.036.0104","DOIUrl":"https://doi.org/10.4003/006.036.0104","url":null,"abstract":"Abstract: \u0000 Where a stream enters a large lake, the mouth represents a transitional environment that is neither truly lotic nor lentic in nature and therefore is likely to affect the fauna present. Theory on habitat area and stream size predicts that species richness will increase farther downstream as watershed size increases, but as stream gradient and thus flow rate declines, stream mouths present a different and understudied habitat. Freshwater mussels in the family Unionidae are in decline, and therefore understanding how they respond across diverse habitats is also critical. We sampled mussel assemblages from 2010 to 2012 in the lower reaches of twelve small tributaries and two large embayments of the western and central basins of Lake Erie, where watershed size ranged from 10 to 4000 km2. These watersheds were assessed for land use by remote sensing and for basic water chemistry and the composition of their benthos by standard protocols. Evidence of native unionid mussels occurred in all watersheds, with 14 species found alive, which make up 75% of mussel species still present throughout Lake Erie. A species-area relationship occurred, although the effect was weaker than that present for flowing streams in the region. Additionally, the habitat and corresponding assemblages were characterized as depositional in nature, which logically follow high agricultural land use and corresponding high levels of turbidity and the proportion of silt and clay. Therefore, the lake environment influenced mussel assemblages, yet these conditions appear to limit dreissenid mussels in river mouths.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"36 1","pages":"31 - 41"},"PeriodicalIF":0.5,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.036.0104","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47239794","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. C. Alejo-Plata, M. Ahumada-Sempoal, Sairi Sarai León Guzmán, J. Herrera-Galindo, M. S. García-Madrigal
Abstract: In this study, trophic ecology of Octopus hubbsorum (Berry, 1953) was examined in relation to the species life cycle and dry and rainy seasons. A total of 184 individuals were obtained from the commercial artisanal catches at different localities along the coast of Oaxaca, Mexican tropical Pacific, from January 2011 to December 2012. Analysis of digestive tract contents revealed that O. hubbsorum preyed upon 43 different prey species belonging to five zoological groups (Crustacean, Mollusca, Teleostei, Echinodermata and Polychaeta), cannibalism was only occasional. The most important prey was the porcelain crabs genus Petrolisthes, contributing 52.1% and 37.8% to the total Index of Relative Importance, in females and males, respectively. Dietary comparison between different maturity stages revealed significant changes in the diet with maturation. The proportion of empty stomachs observed between the dry (18.75 %) and rainy (12.5 %) seasons did not differ significantly (χ2 = 0.55, P > 0.05). Our results suggest that females likely migrate to shallow areas to feed in preparation for mating, they may do this to increase energy intake prior to egg caring and incubation, a period when they do not feed. The high productivity waters along the coast of Oaxaca seem to be important to the survival of this species because they offer key food resources at a critical reproductive stage.
摘要:本研究探讨了hubbsorum (Berry, 1953)章鱼的营养生态学与物种生命周期和旱季和雨季的关系。2011年1月至2012年12月，在墨西哥热带太平洋瓦哈卡州沿岸不同地点，通过商业手工捕捞共捕获184只个体。对其消化道内容物的分析表明，hubbsorum可捕食5个动物类群(甲壳类、软体类、硬骨类、棘皮类和多毛纲)43种不同的猎物，偶有同类相食现象。最重要的猎物为石石瓷蟹属，雌蟹和雄蟹的相对重要性指数分别为52.1%和37.8%。不同成熟期的日粮比较显示，日粮随成熟期的变化显著。干燥季节(18.75%)与雨季(12.5%)空腹比例差异无统计学意义(χ2 = 0.55, P < 0.05)。我们的研究结果表明，雌性可能会迁移到浅水区觅食，为交配做准备，它们这样做可能是为了在照顾卵子和孵化之前增加能量摄入，这段时间它们不进食。瓦哈卡沿岸的高生产力水域似乎对这个物种的生存很重要，因为它们在关键的繁殖阶段提供了关键的食物资源。
{"title":"Diet of Octopus hubbsorum (Cephalopoda: Octopodidae) from the Coast of Oaxaca, México","authors":"M. C. Alejo-Plata, M. Ahumada-Sempoal, Sairi Sarai León Guzmán, J. Herrera-Galindo, M. S. García-Madrigal","doi":"10.4003/006.036.0111","DOIUrl":"https://doi.org/10.4003/006.036.0111","url":null,"abstract":"Abstract: \u0000 In this study, trophic ecology of Octopus hubbsorum (Berry, 1953) was examined in relation to the species life cycle and dry and rainy seasons. A total of 184 individuals were obtained from the commercial artisanal catches at different localities along the coast of Oaxaca, Mexican tropical Pacific, from January 2011 to December 2012. Analysis of digestive tract contents revealed that O. hubbsorum preyed upon 43 different prey species belonging to five zoological groups (Crustacean, Mollusca, Teleostei, Echinodermata and Polychaeta), cannibalism was only occasional. The most important prey was the porcelain crabs genus Petrolisthes, contributing 52.1% and 37.8% to the total Index of Relative Importance, in females and males, respectively. Dietary comparison between different maturity stages revealed significant changes in the diet with maturation. The proportion of empty stomachs observed between the dry (18.75 %) and rainy (12.5 %) seasons did not differ significantly (χ2 = 0.55, P > 0.05). Our results suggest that females likely migrate to shallow areas to feed in preparation for mating, they may do this to increase energy intake prior to egg caring and incubation, a period when they do not feed. The high productivity waters along the coast of Oaxaca seem to be important to the survival of this species because they offer key food resources at a critical reproductive stage.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"36 1","pages":"109 - 118"},"PeriodicalIF":0.5,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.036.0111","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41638652","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}
Nicholas S. Gladstone, Evin T. Carter, M. Mckinney, M. Niemiller
Abstract: Cave-obligate (troglobiotic) land snails are among the most understudied taxa inhabiting cave systems because of their small size and cryptic nature. Other than locality records and general descriptions of species' morphology, information regarding most cave snail taxa is minimal. Given the importance of land snails as indicator species and as important drivers of ecosystem processes, this lack of knowledge on cave-obligate taxa impedes conservation management of subterranean snails and subterranean ecosystems in general. As a first step, we compiled and georeferenced all available distributional records for troglobiotic snail species within two major karst regions in the United States: The Interior Low Plateau (ILP) and Appalachians. We identified 16 new localities among these species from caves in Alabama, Tennessee, and Georgia from 2012 to 2016, yielding 8 new occurrences of two species in the ILP and 8 new occurrences of three species in the Appalachians. In total, we report 143 occurrences for five species in 124 caves, representing the most comprehensive dataset on the distribution of caveobligate snails in the eastern United States to date. We also provide the first IUCN Red List conservation assessments for all five troglobiotic taxa and reexamine NatureServe conservation ranks. Our assessments indicate that three of the five species are considered at an elevated risk of extinction. Given these ranks and the threats identified to each species, we offer recommendations concerning the conservation and management of these cave snails and outline future areas of research for these taxa.
{"title":"Status and Distribution of the Cave-Obligate Land Snails in the Appalachians and Interior Low Plateau of the Eastern United States","authors":"Nicholas S. Gladstone, Evin T. Carter, M. Mckinney, M. Niemiller","doi":"10.4003/006.036.0107","DOIUrl":"https://doi.org/10.4003/006.036.0107","url":null,"abstract":"Abstract: \u0000 Cave-obligate (troglobiotic) land snails are among the most understudied taxa inhabiting cave systems because of their small size and cryptic nature. Other than locality records and general descriptions of species' morphology, information regarding most cave snail taxa is minimal. Given the importance of land snails as indicator species and as important drivers of ecosystem processes, this lack of knowledge on cave-obligate taxa impedes conservation management of subterranean snails and subterranean ecosystems in general. As a first step, we compiled and georeferenced all available distributional records for troglobiotic snail species within two major karst regions in the United States: The Interior Low Plateau (ILP) and Appalachians. We identified 16 new localities among these species from caves in Alabama, Tennessee, and Georgia from 2012 to 2016, yielding 8 new occurrences of two species in the ILP and 8 new occurrences of three species in the Appalachians. In total, we report 143 occurrences for five species in 124 caves, representing the most comprehensive dataset on the distribution of caveobligate snails in the eastern United States to date. We also provide the first IUCN Red List conservation assessments for all five troglobiotic taxa and reexamine NatureServe conservation ranks. Our assessments indicate that three of the five species are considered at an elevated risk of extinction. Given these ranks and the threats identified to each species, we offer recommendations concerning the conservation and management of these cave snails and outline future areas of research for these taxa.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"36 1","pages":"62 - 78"},"PeriodicalIF":0.5,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.036.0107","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48448760","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: Terrestrial mollusks (land snails and slugs) are an important component of the terrestrial ecosystem, yet for most species their distribution is not well known. This study was a comprehensive inventory of terrestrial mollusks in Knox County, Tennessee; an area within the Valley and Ridge physiographic region rich in calcareous soils and bluffs. Knox County supports a total of 151 species, including 70 newly reported to the county and 15 newly reported to Tennessee. Sixteen species non-native to North America were found, mostly in urban/ residential habitats. Limestone/sandstone bluffs were found to have the highest diversity of terrestrial mollusks.
{"title":"An Inventory of the Land Snails and Slugs (Gastropoda: Caenogastropoda and Pulmonata) of Knox County, Tennessee","authors":"B. Dinkins, Gerald R. Dinkins","doi":"10.4003/006.036.0101","DOIUrl":"https://doi.org/10.4003/006.036.0101","url":null,"abstract":"Abstract: Terrestrial mollusks (land snails and slugs) are an important component of the terrestrial ecosystem, yet for most species their distribution is not well known. This study was a comprehensive inventory of terrestrial mollusks in Knox County, Tennessee; an area within the Valley and Ridge physiographic region rich in calcareous soils and bluffs. Knox County supports a total of 151 species, including 70 newly reported to the county and 15 newly reported to Tennessee. Sixteen species non-native to North America were found, mostly in urban/ residential habitats. Limestone/sandstone bluffs were found to have the highest diversity of terrestrial mollusks.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"36 1","pages":"1 - 22"},"PeriodicalIF":0.5,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.036.0101","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44954997","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. Marshall, Joshua A. Banta, L. Williams, M. Williams, J. S. Placyk
Abstract: Fish have an ecologically significant role in the life-history of unionid freshwater mussels, as the larvae of most species are obligate ectoparasites (glochidia) on fish hosts. Although this ecological interaction is vital to freshwater mussel conservation, there is a paucity of data on fish-host specificity for many species. A species-specific DNA barcoding dataset utilizing the mitochondrial NADH dehydrogenase subunit 1 (ND1) gene was used to identify 154 glochidia attached to wild fish collected from March through August of 2013 in the Sabine and Neches rivers in Texas, U.S.A. These data include the first report of potential hosts for two state-threatened species, Fusconaia askewi (Marsh, 1896) and Pleurobema riddellii (I. Lea, 1862), as well as potential hosts for Amblema plicata (Say, 1817), Obliquaria reflexa (Rafinesque, 1820), Plectomerus dombeyanus (Valenciennes, 1827), Potamilus purpuratus (Lamarck, 1819), Quadrula mortoni (I. Lea, 1831), Q. verrucosa (Rafinesque, 1820), and Truncilla truncata (Rafinesque, 1820). Cyprinella lutrensis appears to be the primary host for F. askewi, as 50% (54/108) of its glochidia were found on this minnow species alone. Pleurobema riddellii may be a cyprinid specialist, infesting only C. lutrensis and Pimephales vigilax. Alternatively, F. askewi may be a host generalist, as glochidia were found encysted on 17 fish species suggesting that host fish availability may not be an important factor contributing to observed population declines. The findings here will be instrumental in the future conservation of these species, through the translocation to correct habitat and developing successful propagation programs
{"title":"DNA Barcoding Permits Identification of Potential Fish Hosts of Unionid Freshwater Mussels","authors":"N. Marshall, Joshua A. Banta, L. Williams, M. Williams, J. S. Placyk","doi":"10.4003/006.036.0114","DOIUrl":"https://doi.org/10.4003/006.036.0114","url":null,"abstract":"Abstract: \u0000 Fish have an ecologically significant role in the life-history of unionid freshwater mussels, as the larvae of most species are obligate ectoparasites (glochidia) on fish hosts. Although this ecological interaction is vital to freshwater mussel conservation, there is a paucity of data on fish-host specificity for many species. A species-specific DNA barcoding dataset utilizing the mitochondrial NADH dehydrogenase subunit 1 (ND1) gene was used to identify 154 glochidia attached to wild fish collected from March through August of 2013 in the Sabine and Neches rivers in Texas, U.S.A. These data include the first report of potential hosts for two state-threatened species, Fusconaia askewi (Marsh, 1896) and Pleurobema riddellii (I. Lea, 1862), as well as potential hosts for Amblema plicata (Say, 1817), Obliquaria reflexa (Rafinesque, 1820), Plectomerus dombeyanus (Valenciennes, 1827), Potamilus purpuratus (Lamarck, 1819), Quadrula mortoni (I. Lea, 1831), Q. verrucosa (Rafinesque, 1820), and Truncilla truncata (Rafinesque, 1820). Cyprinella lutrensis appears to be the primary host for F. askewi, as 50% (54/108) of its glochidia were found on this minnow species alone. Pleurobema riddellii may be a cyprinid specialist, infesting only C. lutrensis and Pimephales vigilax. Alternatively, F. askewi may be a host generalist, as glochidia were found encysted on 17 fish species suggesting that host fish availability may not be an important factor contributing to observed population declines. The findings here will be instrumental in the future conservation of these species, through the translocation to correct habitat and developing successful propagation programs","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"36 1","pages":"42 - 56"},"PeriodicalIF":0.5,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.036.0114","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42884992","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}
Cynthia G. Norton, Angela F. Johnson, Betsy M. Nelson
Abstract: In many species, the difference between pigmented and non-pigmented individuals is due to a single recessive Mendelian gene. We have demonstrated that this is also the case in the freshwater hermaphroditic snail, Planorbella trivolvis (Say, 1817), and established an albino population with comparable genetic background to a wild population so that pigmentation can be used as a visible genetic marker to better understand the reproductive biology of these mollusks. We carried out Mendelian crosses between albino (A) individuals from an inbred laboratory strain and pigmented (P) individuals one generation removed from a natural population and assessed pigmentation of progeny from eggs collected immediately after mating and 11 weeks later. Results of parental, F1, and F2 generations and backcrosses to pure-breeding albinos were consistent with a Mendelian single gene inheritance pattern. Because we never observed albino progeny from any albino snails mated to pigmented sperm donors, we also confirmed that selfing is rare in P. trivolvis. A simple non-invasive paternity marker in this unusual hermaphrodite snail that displays almost no self-fertilization will facilitate experiments to understand its reproductive biology and provide a more complete picture of hermaphrodite mating strategies.
{"title":"The Genetic Basis of Albinism in the Hermaphroditic Freshwater Snail Planorbella trivolvis","authors":"Cynthia G. Norton, Angela F. Johnson, Betsy M. Nelson","doi":"10.4003/006.036.0110","DOIUrl":"https://doi.org/10.4003/006.036.0110","url":null,"abstract":"Abstract: \u0000 In many species, the difference between pigmented and non-pigmented individuals is due to a single recessive Mendelian gene. We have demonstrated that this is also the case in the freshwater hermaphroditic snail, Planorbella trivolvis (Say, 1817), and established an albino population with comparable genetic background to a wild population so that pigmentation can be used as a visible genetic marker to better understand the reproductive biology of these mollusks. We carried out Mendelian crosses between albino (A) individuals from an inbred laboratory strain and pigmented (P) individuals one generation removed from a natural population and assessed pigmentation of progeny from eggs collected immediately after mating and 11 weeks later. Results of parental, F1, and F2 generations and backcrosses to pure-breeding albinos were consistent with a Mendelian single gene inheritance pattern. Because we never observed albino progeny from any albino snails mated to pigmented sperm donors, we also confirmed that selfing is rare in P. trivolvis. A simple non-invasive paternity marker in this unusual hermaphrodite snail that displays almost no self-fertilization will facilitate experiments to understand its reproductive biology and provide a more complete picture of hermaphrodite mating strategies.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"36 1","pages":"153 - 157"},"PeriodicalIF":0.5,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.036.0110","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46937517","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: Population density commonly affects snail biology and is an important ecological factor to consider in any pest control program because population growth rates can be affected. Lissachatina fulica (Bowdich, 1822) is a pest of plants throughout the worldwide tropics; however, its biology is not completely known. We studied the effects of three rearing densities: low (5 snails per 25 × 38 × 17 cm (L × W × H) cage), medium (15 snails), or high (35 snails), on L. fulica growth, reproduction, and survival. High rearing density reduced growth, affected the initiation of egg laying, and reduced the number of eggs laid per snail and per clutch. Mortality did not increase with high rearing density, nor was any cannibalism observed, even when snails were deprived of food. Juvenile snail survival was more affected by lack of food than was adult survival, and availability of calcium did not compensate for lack of food. High-density rearing effects were not likely caused by limited food, calcium, or oxygen.
{"title":"Effects of Density and Food Deprivation on Growth, Reproduction, and Survival of Lissachatina fulica","authors":"Katrina L. Dickens, J. Capinera, T. Smith","doi":"10.4003/006.036.0115","DOIUrl":"https://doi.org/10.4003/006.036.0115","url":null,"abstract":"Abstract: Population density commonly affects snail biology and is an important ecological factor to consider in any pest control program because population growth rates can be affected. Lissachatina fulica (Bowdich, 1822) is a pest of plants throughout the worldwide tropics; however, its biology is not completely known. We studied the effects of three rearing densities: low (5 snails per 25 × 38 × 17 cm (L × W × H) cage), medium (15 snails), or high (35 snails), on L. fulica growth, reproduction, and survival. High rearing density reduced growth, affected the initiation of egg laying, and reduced the number of eggs laid per snail and per clutch. Mortality did not increase with high rearing density, nor was any cannibalism observed, even when snails were deprived of food. Juvenile snail survival was more affected by lack of food than was adult survival, and availability of calcium did not compensate for lack of food. High-density rearing effects were not likely caused by limited food, calcium, or oxygen.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"36 1","pages":"57 - 61"},"PeriodicalIF":0.5,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.036.0115","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43240274","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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