Nathan Hollenbeck, D. Scheel, Megan C Gravley, G. K. Sage, R. Toussaint, S. Talbot
Abstract: We evaluated the efficacy of using swabs to collect cells from the epidermis of octopus as a non-invasive DNA source for classical genetic studies, and demonstrated value of the technique by incorporating it into an effort to determine, within a day, the lineage of captured, live Enteroctopus (E. dofleini or a cryptic lineage). The cryptic lineage was targeted for captive behavioral and morphological studies, while once genetically identified, the non-target lineage could be more rapidly released back to the wild. We used commercially available sterile foamtipped swabs and a high-salt preservation buffer to collect and store paired swab and muscle (arm tip) tissue sampled from live Enteroctopus collected from Prince William Sound, Alaska. We performed a one-day extraction of DNA from epithelial swab samples and amplification of two diagnostic microsatellite loci to determine the lineage of each of the 21 individuals. Following this rapid lineage assessment, which allowed us to release non-target individuals within a day of laboratory work, we compared paired swab and muscle tissue samples from each individual to assess quantity of DNA yields and consistency of genotyping results, followed by assessment of locus-by-locus reliability of DNA extracts from swabs. Epithelial swabs yielded, on average, lower quantities of DNA (170.32 ± 74.72 (SD) ng/μL) relative to DNA obtained from tissues collected using invasive or destructive techniques (310.95 ± 147.37 (SD) ng/μL. We observed some decrease in yields of DNA from extractions of swab samples conducted 19 and 31 months after initial extractions when samples were stored at room temperature in lysis buffer. All extractions yielded quantities of DNA sufficient to amplify and score all loci, which included fragment data from 10 microsatellite loci (nine polymorphic loci and monomorphic locus EdoμA106), and nucleotide sequence data from a 528 base pair portion of the nuclear octopine dehydrogenase gene. All results from genotyping and sequencing using paired swab and muscle tissue extracts were concordant, and experimental reliability levels for multilocus genotypes generated from swab samples exceeded 97%. This technique is useful for studies in which invasive sampling is not optimal, and in remote field situations since samples can be stored at ambient temperatures for at least 31 months. The use of epithelial swabs is thus a noninvasive technique appropriate for sampling genetic material from live octopuses for use in classical genetic studies as well as supporting experimental and behavioral studies.
{"title":"Use of Swabs for Sampling Epithelial Cells for Molecular Genetics Analyses in Enteroctopus","authors":"Nathan Hollenbeck, D. Scheel, Megan C Gravley, G. K. Sage, R. Toussaint, S. Talbot","doi":"10.4003/006.035.0207","DOIUrl":"https://doi.org/10.4003/006.035.0207","url":null,"abstract":"Abstract: \u0000 We evaluated the efficacy of using swabs to collect cells from the epidermis of octopus as a non-invasive DNA source for classical genetic studies, and demonstrated value of the technique by incorporating it into an effort to determine, within a day, the lineage of captured, live Enteroctopus (E. dofleini or a cryptic lineage). The cryptic lineage was targeted for captive behavioral and morphological studies, while once genetically identified, the non-target lineage could be more rapidly released back to the wild. We used commercially available sterile foamtipped swabs and a high-salt preservation buffer to collect and store paired swab and muscle (arm tip) tissue sampled from live Enteroctopus collected from Prince William Sound, Alaska. We performed a one-day extraction of DNA from epithelial swab samples and amplification of two diagnostic microsatellite loci to determine the lineage of each of the 21 individuals. Following this rapid lineage assessment, which allowed us to release non-target individuals within a day of laboratory work, we compared paired swab and muscle tissue samples from each individual to assess quantity of DNA yields and consistency of genotyping results, followed by assessment of locus-by-locus reliability of DNA extracts from swabs. Epithelial swabs yielded, on average, lower quantities of DNA (170.32 ± 74.72 (SD) ng/μL) relative to DNA obtained from tissues collected using invasive or destructive techniques (310.95 ± 147.37 (SD) ng/μL. We observed some decrease in yields of DNA from extractions of swab samples conducted 19 and 31 months after initial extractions when samples were stored at room temperature in lysis buffer. All extractions yielded quantities of DNA sufficient to amplify and score all loci, which included fragment data from 10 microsatellite loci (nine polymorphic loci and monomorphic locus EdoμA106), and nucleotide sequence data from a 528 base pair portion of the nuclear octopine dehydrogenase gene. All results from genotyping and sequencing using paired swab and muscle tissue extracts were concordant, and experimental reliability levels for multilocus genotypes generated from swab samples exceeded 97%. This technique is useful for studies in which invasive sampling is not optimal, and in remote field situations since samples can be stored at ambient temperatures for at least 31 months. The use of epithelial swabs is thus a noninvasive technique appropriate for sampling genetic material from live octopuses for use in classical genetic studies as well as supporting experimental and behavioral studies.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"35 1","pages":"145 - 157"},"PeriodicalIF":0.5,"publicationDate":"2017-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.035.0207","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49481105","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: We tested whether body patterns distinguished two haplotypes of large octopus in Prince William Sound Alaska. Live octopuses were photographed in captivity and assigned to a morphotype based on whether longitudinal mantle folds (a characteristic body pattern feature of the giant Pacific octopus (GPO), Enteroctopus dofleini (Wülker 1910)) were present (the GPO morphotype, N = 14) or absent (a novel morphotype, N = 6). Novel morphotype octopuses were distinguished without exception from GPO morphotype octopuses by the presence of a lateral mantle frill and the absence of longitudinal mantle folds, ventral mantle texture below the lateral frill, and patch and groove patterning. Additional traits could be used in combination to reliably characterize the novel morphotype. The genetic haplotypes of these octopuses were determined from nucleotide sequence data from two microsatellite loci and a portion of the OCDE gene. The GPO morphotype was identified with E. dofleini based on the match of body pattern traits to published descriptions of that species and the match of its genetic haplotype to published sequences of E. dofleini. Novel morphotype body patterns did not match descriptions of any species from the eastern north Pacific, while its genetic haplotype matched that of a recently sequenced undescribed octopus. The GPO and novel morphotypes are sister clades, and body pattern traits reliably identified individuals to morphotype and haplotype. Body pattern traits can be used in field identification of live octopuses allowing population assessments, by-catch frequency estimates, and other studies of both octopus types. We offer the common name of the frilled giant Pacific octopus for the novel morphotype, and based on genetic and morphological data suggest this clade is a new species of large Pacific octopus in the genus Enteroctopus. A full species description remains to be done.
{"title":"Body Patterns of the Frilled Giant Pacific Octopus, a New Species of Octopus from Prince William Sound, AK","authors":"Nathan Hollenbeck, D. Scheel","doi":"10.4003/006.035.0206","DOIUrl":"https://doi.org/10.4003/006.035.0206","url":null,"abstract":"Abstract: \u0000 We tested whether body patterns distinguished two haplotypes of large octopus in Prince William Sound Alaska. Live octopuses were photographed in captivity and assigned to a morphotype based on whether longitudinal mantle folds (a characteristic body pattern feature of the giant Pacific octopus (GPO), Enteroctopus dofleini (Wülker 1910)) were present (the GPO morphotype, N = 14) or absent (a novel morphotype, N = 6). Novel morphotype octopuses were distinguished without exception from GPO morphotype octopuses by the presence of a lateral mantle frill and the absence of longitudinal mantle folds, ventral mantle texture below the lateral frill, and patch and groove patterning. Additional traits could be used in combination to reliably characterize the novel morphotype. The genetic haplotypes of these octopuses were determined from nucleotide sequence data from two microsatellite loci and a portion of the OCDE gene. The GPO morphotype was identified with E. dofleini based on the match of body pattern traits to published descriptions of that species and the match of its genetic haplotype to published sequences of E. dofleini. Novel morphotype body patterns did not match descriptions of any species from the eastern north Pacific, while its genetic haplotype matched that of a recently sequenced undescribed octopus. The GPO and novel morphotypes are sister clades, and body pattern traits reliably identified individuals to morphotype and haplotype. Body pattern traits can be used in field identification of live octopuses allowing population assessments, by-catch frequency estimates, and other studies of both octopus types. We offer the common name of the frilled giant Pacific octopus for the novel morphotype, and based on genetic and morphological data suggest this clade is a new species of large Pacific octopus in the genus Enteroctopus. A full species description remains to be done.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"35 1","pages":"134 - 144"},"PeriodicalIF":0.5,"publicationDate":"2017-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.035.0206","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46046312","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 veliconcha larva of the predatory gastropod Conus spurius Gmelin, 1791 is described and for the first time illustrated based on material from Sanibel Island, Florida. Hatchling veliconchas were 1470–1570 μm (mean = 1530) long, with first protoconch whorl maximum diameter 670–740 μm (mean = 710), and estimated egg diameter 570 μm. Veliconchas can swim for a few minutes to a few hours before settling. They have well-developed paired velar lobes each 600–700 μm in length, an extensible foot with a distinct metapodium separated from the remainder of the foot by a transverse fold, and operculum. Several early life history traits of C. spurius, particularly hatching as large veliconcha larvae with predominantly lecithotrophic, nearly non-planktonic development, closely resemble those of a well-defined clade of Conus Linnaeus, 1758 species that prey on other gastropods. They contrast with the majority of species in this hyperdiverse genus, which hatch as much smaller planktonic, obligatory planktotrophic veliger larvae. As adults they comprise a vermivorous feeding guild, preying exclusively or nearly so on polychaete annelids. Limited data suggest that C. spurius may share this trait with them but it may also prey on molluscs. Recent molecular phylogenetic trees suggest that the characters “pelagic development” and “non-pelagic development” (or nearly so: <1 day) are distributed independently of phylogeny in the larger clade that includes C. spurius and the molluscivorous species. Similarities in veliconcha morphology and developmental mode, adult radular tooth morphometry, phylogenetic position, and earliest fossil records suggest the speculative hypothesis that the monophyletic clade of extant molluscivorous Conus species may have evolved in the Miocene from a vermivore or mixed vermivorous-molluscivorous ancestor with these attributes, such as C. spurius.
{"title":"A Veliconcha Unveiled: Observations on the Larva and Radula of Conus spurius, with Implications for the Origin of Molluscivory in Conus","authors":"J. Leal, A. Kohn, Rebecca A Mensch","doi":"10.4003/006.035.0203","DOIUrl":"https://doi.org/10.4003/006.035.0203","url":null,"abstract":"Abstract: \u0000 The veliconcha larva of the predatory gastropod Conus spurius Gmelin, 1791 is described and for the first time illustrated based on material from Sanibel Island, Florida. Hatchling veliconchas were 1470–1570 μm (mean = 1530) long, with first protoconch whorl maximum diameter 670–740 μm (mean = 710), and estimated egg diameter 570 μm. Veliconchas can swim for a few minutes to a few hours before settling. They have well-developed paired velar lobes each 600–700 μm in length, an extensible foot with a distinct metapodium separated from the remainder of the foot by a transverse fold, and operculum. Several early life history traits of C. spurius, particularly hatching as large veliconcha larvae with predominantly lecithotrophic, nearly non-planktonic development, closely resemble those of a well-defined clade of Conus Linnaeus, 1758 species that prey on other gastropods. They contrast with the majority of species in this hyperdiverse genus, which hatch as much smaller planktonic, obligatory planktotrophic veliger larvae. As adults they comprise a vermivorous feeding guild, preying exclusively or nearly so on polychaete annelids. Limited data suggest that C. spurius may share this trait with them but it may also prey on molluscs. Recent molecular phylogenetic trees suggest that the characters “pelagic development” and “non-pelagic development” (or nearly so: <1 day) are distributed independently of phylogeny in the larger clade that includes C. spurius and the molluscivorous species. Similarities in veliconcha morphology and developmental mode, adult radular tooth morphometry, phylogenetic position, and earliest fossil records suggest the speculative hypothesis that the monophyletic clade of extant molluscivorous Conus species may have evolved in the Miocene from a vermivore or mixed vermivorous-molluscivorous ancestor with these attributes, such as C. spurius.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"35 1","pages":"111 - 118"},"PeriodicalIF":0.5,"publicationDate":"2017-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.035.0203","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41981219","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}
Russell L. Minton, Rochelle R. Beasley, S. Lance, Kathryn E. Perez
Abstract: We developed and characterized 13 polymorphic microsatellite loci in South Texas species of Praticolella von Martens, 1892 (Gastropoda: Polygyridae), some of which have restricted distributions and can be difficult to identify using traditional shell characters. To make this genomic tool more broadly useful in these species, instead of characterizing loci in many individuals of a single species, we tested them across five populations of four different species. Twelve loci amplified in all four species tested, and eleven loci showed deviations from Hardy-Weinberg equilibrium. These loci will be valuable in assessing species identity and population genetic connectivity among South Texas Praticolella.
摘要/ Abstract摘要:在南德克萨斯种Praticolella von Martens, 1892(腹足目:多角蝽科)中开发并鉴定了13个多态微卫星位点，其中一些位点分布受限，难以用传统的壳性状进行鉴定。为了使这个基因组工具在这些物种中更广泛地应用，我们不是在单个物种的许多个体中表征位点，而是在四个不同物种的五个种群中进行了测试。在所有4个被测物种中有12个位点扩增，11个位点偏离Hardy-Weinberg平衡。这些基因座对评估南德克萨斯鸡的物种特性和种群遗传连通性具有重要价值。
{"title":"Development, Characterization, and Utility of 13 Polymorphic Microsatellite Loci in Praticolella (Gastropoda: Polygyridae) Species from South Texas, U.S.A.","authors":"Russell L. Minton, Rochelle R. Beasley, S. Lance, Kathryn E. Perez","doi":"10.4003/006.035.0208","DOIUrl":"https://doi.org/10.4003/006.035.0208","url":null,"abstract":"Abstract: \u0000 We developed and characterized 13 polymorphic microsatellite loci in South Texas species of Praticolella von Martens, 1892 (Gastropoda: Polygyridae), some of which have restricted distributions and can be difficult to identify using traditional shell characters. To make this genomic tool more broadly useful in these species, instead of characterizing loci in many individuals of a single species, we tested them across five populations of four different species. Twelve loci amplified in all four species tested, and eleven loci showed deviations from Hardy-Weinberg equilibrium. These loci will be valuable in assessing species identity and population genetic connectivity among South Texas Praticolella.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"35 1","pages":"158 - 162"},"PeriodicalIF":0.5,"publicationDate":"2017-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.035.0208","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46182719","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, E. Naranjo-García, G. Zúñiga
Abstract: This study reports the current distribution in Mexico of Deroceras laeve (Müller, 1774) and D. invadens Reise, Hutchinson, Schunack and Schlitt, 2011, both previously recorded, and the first records of D. reticulatum (Müller, 1774) in this country. The taxonomic identifications were made on the basis of morphology and DNA sequences of a fragment of the cytochrome oxidase I gene. A phylogenetic analysis by maximum likelihood was carried out in order to support the identification and to explore the association of Mexican specimens. D. reticulatum and D. invadens appear restricted to the central portion of the country while D. laeve is widely distributed. Due to the invasive and pest character of these species, it is important to know their distribution in the country and the possible risk to native fauna and crops.
{"title":"The Exotic Slugs of the Genus Deroceras (Agriolimacidae) in Mexico: Morphological and Molecular Characterization, and New Data on Their Distribution","authors":"Victoria Araiza-Gómez, E. Naranjo-García, G. Zúñiga","doi":"10.4003/006.035.0205","DOIUrl":"https://doi.org/10.4003/006.035.0205","url":null,"abstract":"Abstract: \u0000 This study reports the current distribution in Mexico of Deroceras laeve (Müller, 1774) and D. invadens Reise, Hutchinson, Schunack and Schlitt, 2011, both previously recorded, and the first records of D. reticulatum (Müller, 1774) in this country. The taxonomic identifications were made on the basis of morphology and DNA sequences of a fragment of the cytochrome oxidase I gene. A phylogenetic analysis by maximum likelihood was carried out in order to support the identification and to explore the association of Mexican specimens. D. reticulatum and D. invadens appear restricted to the central portion of the country while D. laeve is widely distributed. Due to the invasive and pest character of these species, it is important to know their distribution in the country and the possible risk to native fauna and crops.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"35 1","pages":"126 - 133"},"PeriodicalIF":0.5,"publicationDate":"2017-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.035.0205","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45103150","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 capabilities of suspension-feeding bivalve molluscs to discriminately ingest particles are well known. Physicochemical properties of particles have been shown to play a role in mediating post-capture selection in these animals. In particular, particle surface charge and wettability, a proxy for hydrophobic-hydrophilic forces, can be used by different bivalve species as determinants of selection. How physicochemical factors of particles affect their capture, however, have been little studied. To investigate such interactions, a series of adhesion assays and particle capture experiments were designed. First, mucus from the gills of the blue mussel, Mytilus edulis (Linnaeus 1758), and the bay scallop, Argopecten irradians (Lamarck 1819), were isolated separately, adsorbed onto glass microscope slides, and incubated with polystyrene microspheres (10 μm) that were either untreated or covalently bound to different neoglycoproteins (NGP; N-acetyl-glucosamine, D-mannose), or bovine serum albumin (BSA). Adhesion of treated and untreated microspheres to slides with and without mucus was quantified and statistically compared. Secondly, untreated microspheres and spheres with covalently bound NGP and BSA (ranging from 2 to 10 μm in diameter) were directly delivered to the incurrent aperture of bivalves. The excurrent water was sampled, and capture efficiencies (CE) calculated. Results demonstrate that the presence of epiparticulate BSA and NGP can significantly change the surface characteristics of microspheres, but these differences had minimal effect on adhesion to mucus or CE. A notable exception was a significant reduction in CE of D-mannose-treated 2- and 3-μm diameter microspheres by mussels compared to the control spheres of the same size. Overall, results of this study suggest that mussels and scallops can efficiently capture particles with a range of physicochemical surface properties. These findings conform to previously reported effects of particle surface properties on CE of particles by suspension-feeding bivalve larvae, but not deposit feeders.
{"title":"Effects of Surface Properties on Particle Capture by Two Species of Suspension-Feeding Bivalve Molluscs","authors":"M. Rosa, J. Ward, Ashley Frink, S. Shumway","doi":"10.4003/006.035.0212","DOIUrl":"https://doi.org/10.4003/006.035.0212","url":null,"abstract":"Abstract: \u0000 The capabilities of suspension-feeding bivalve molluscs to discriminately ingest particles are well known. Physicochemical properties of particles have been shown to play a role in mediating post-capture selection in these animals. In particular, particle surface charge and wettability, a proxy for hydrophobic-hydrophilic forces, can be used by different bivalve species as determinants of selection. How physicochemical factors of particles affect their capture, however, have been little studied. To investigate such interactions, a series of adhesion assays and particle capture experiments were designed. First, mucus from the gills of the blue mussel, Mytilus edulis (Linnaeus 1758), and the bay scallop, Argopecten irradians (Lamarck 1819), were isolated separately, adsorbed onto glass microscope slides, and incubated with polystyrene microspheres (10 μm) that were either untreated or covalently bound to different neoglycoproteins (NGP; N-acetyl-glucosamine, D-mannose), or bovine serum albumin (BSA). Adhesion of treated and untreated microspheres to slides with and without mucus was quantified and statistically compared. Secondly, untreated microspheres and spheres with covalently bound NGP and BSA (ranging from 2 to 10 μm in diameter) were directly delivered to the incurrent aperture of bivalves. The excurrent water was sampled, and capture efficiencies (CE) calculated. Results demonstrate that the presence of epiparticulate BSA and NGP can significantly change the surface characteristics of microspheres, but these differences had minimal effect on adhesion to mucus or CE. A notable exception was a significant reduction in CE of D-mannose-treated 2- and 3-μm diameter microspheres by mussels compared to the control spheres of the same size. Overall, results of this study suggest that mussels and scallops can efficiently capture particles with a range of physicochemical surface properties. These findings conform to previously reported effects of particle surface properties on CE of particles by suspension-feeding bivalve larvae, but not deposit feeders.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"35 1","pages":"181 - 188"},"PeriodicalIF":0.5,"publicationDate":"2017-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.035.0212","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42981647","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}
María J. Tiecher, M. E. Seuffert, S. Burela, P. Martín
Abstract: Apple snails are regarded as invasive or potentially problematic species but some species may be under threat. Life tables are a useful tool to understand the growth potential of freshwater snail populations. Our aim was to estimate the demographic parameters of the Neotropical apple snail Asolene platae (Maton, 1811) to allow a quantitative comparison with invasive apple snails like Pomacea canaliculata (Lamarck, 1822). Life tables were calculated for three laboratory cohorts bred at 25 °C. Life expectancy rises abruptly up to 32–37 months after a period of high post-hatching mortality of one month. The reproductive value peaked at 15–19 months for two cohorts and at 33 months in the other one. The net reproductive rates (R0), generation times (GT) and intrinsic rates of increase (r) were as 55.86 hatchlings, 25.7 months, and 0.188 individuals per individual per month on average, respectively. Among freshwater snails there is a clear inverse relationship between r and GT while R0 has a minor positive influence. The values of GT and r for A. platae are among the highest and lowest, respectively, calculated for freshwater snails at 24–26 °C. These low values of r under optimum conditions indicate a relatively low potential of A. platae populations to increase in new habitats or to recover from disturbances.
{"title":"Life Table and Demographic Parameters of the Neotropical Apple Snail Asolene platae (Caenogastropoda, Ampullariidae)","authors":"María J. Tiecher, M. E. Seuffert, S. Burela, P. Martín","doi":"10.4003/006.035.0204","DOIUrl":"https://doi.org/10.4003/006.035.0204","url":null,"abstract":"Abstract: \u0000 Apple snails are regarded as invasive or potentially problematic species but some species may be under threat. Life tables are a useful tool to understand the growth potential of freshwater snail populations. Our aim was to estimate the demographic parameters of the Neotropical apple snail Asolene platae (Maton, 1811) to allow a quantitative comparison with invasive apple snails like Pomacea canaliculata (Lamarck, 1822). Life tables were calculated for three laboratory cohorts bred at 25 °C. Life expectancy rises abruptly up to 32–37 months after a period of high post-hatching mortality of one month. The reproductive value peaked at 15–19 months for two cohorts and at 33 months in the other one. The net reproductive rates (R0), generation times (GT) and intrinsic rates of increase (r) were as 55.86 hatchlings, 25.7 months, and 0.188 individuals per individual per month on average, respectively. Among freshwater snails there is a clear inverse relationship between r and GT while R0 has a minor positive influence. The values of GT and r for A. platae are among the highest and lowest, respectively, calculated for freshwater snails at 24–26 °C. These low values of r under optimum conditions indicate a relatively low potential of A. platae populations to increase in new habitats or to recover from disturbances.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"35 1","pages":"119 - 125"},"PeriodicalIF":0.5,"publicationDate":"2017-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.035.0204","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44947004","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: Two new species of Xanthochorus Fischer 1884 (X. disalvoi sp. nov. and X. mogolloni sp. nov.) and two new species of Urosalpinx Stimpson 1865 (U. devriesi sp. nov. and U. lancellottii sp. nov.) are described from central Chile. Xanthochorus disalvoi sp. nov. is compared with X. cassidiformis (Blainville, 1832) and X. buxeus (Broderip, 1833). It differs from X. cassidiformis in having a comparatively smaller and narrower shell, a longer siphonal canal, a narrower aperture and narrower axial ribs, while broader or even absent in X. cassidiformis. It differs from X. buxeus in having a lower spire, a broader, less elongate shell with a lower spire, a comparatively longer siphonal canal a narrower aperture and a different spiral sculpture morphology. Xanthochorus mogolloni sp. nov. is also compared with X. buxeus, it differs mainly in having narrower primary and secondary cords, a longer siphonal canal and a lower spire. Urosalpinx devriesi sp. nov. is compared with Urosalpinx cala (Pilsbry, 1897). Urosalpinx devriesi differs in having a lower spire, a longer siphonal canal and a different spiral sculpture morphology. Urosalpinx lancellottii sp. nov. is compared with U. subangulata (Stearns, 1873); it differs in protoconch, axial ribs and spiral sculpture morphology. It differs from Vokesinotus perrugatus (Conrad, 1846) in having an obviously more fragile and smaller shell, and also in having different spiral sculpture morphology. The radulae of Xanthochorus cassidiformis and X. buxeus are illustrated.
{"title":"Description of New Species of Xanthochorus Fischer, 1884 and Urosalpinx Stimpson, 1865 (Mollusca, Gastropoda, Muricidae, Ocenebrinae) from Central Chile","authors":"R. Houart, J. Sellanes","doi":"10.4003/006.035.0202","DOIUrl":"https://doi.org/10.4003/006.035.0202","url":null,"abstract":"Abstract: \u0000 Two new species of Xanthochorus Fischer 1884 (X. disalvoi sp. nov. and X. mogolloni sp. nov.) and two new species of Urosalpinx Stimpson 1865 (U. devriesi sp. nov. and U. lancellottii sp. nov.) are described from central Chile. Xanthochorus disalvoi sp. nov. is compared with X. cassidiformis (Blainville, 1832) and X. buxeus (Broderip, 1833). It differs from X. cassidiformis in having a comparatively smaller and narrower shell, a longer siphonal canal, a narrower aperture and narrower axial ribs, while broader or even absent in X. cassidiformis. It differs from X. buxeus in having a lower spire, a broader, less elongate shell with a lower spire, a comparatively longer siphonal canal a narrower aperture and a different spiral sculpture morphology. Xanthochorus mogolloni sp. nov. is also compared with X. buxeus, it differs mainly in having narrower primary and secondary cords, a longer siphonal canal and a lower spire. Urosalpinx devriesi sp. nov. is compared with Urosalpinx cala (Pilsbry, 1897). Urosalpinx devriesi differs in having a lower spire, a longer siphonal canal and a different spiral sculpture morphology. Urosalpinx lancellottii sp. nov. is compared with U. subangulata (Stearns, 1873); it differs in protoconch, axial ribs and spiral sculpture morphology. It differs from Vokesinotus perrugatus (Conrad, 1846) in having an obviously more fragile and smaller shell, and also in having different spiral sculpture morphology. The radulae of Xanthochorus cassidiformis and X. buxeus are illustrated.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"35 1","pages":"101 - 110"},"PeriodicalIF":0.5,"publicationDate":"2017-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.035.0202","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47923709","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: In this paper, a new species in the genus Graphis Jeffreys, 1867 is described. Graphis peruviana sp. nov. from Chérrepe Beach (7°10′34″S, 79°41′25″W), Lambayeque, Peru, represents the first report of a member of the genus Graphis in the eastern South Pacific.
{"title":"First Report of the Genus Graphis (Gastropoda: Tofanellidae) in the Eastern South Pacific, with a Description of a New Species","authors":"L. E. C. Siadén, J. Céspedes, H. Kajihara","doi":"10.4003/006.035.0209","DOIUrl":"https://doi.org/10.4003/006.035.0209","url":null,"abstract":"Abstract: \u0000 In this paper, a new species in the genus Graphis Jeffreys, 1867 is described. Graphis peruviana sp. nov. from Chérrepe Beach (7°10′34″S, 79°41′25″W), Lambayeque, Peru, represents the first report of a member of the genus Graphis in the eastern South Pacific.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"35 1","pages":"163 - 169"},"PeriodicalIF":0.5,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.035.0209","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48778926","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 invasive New Zealand mud snail, Potamopyrgus antipodarum (Gray 1843), has been present in the Laurentian Great Lakes for at least 20 years. Recently, the snail has spread to streams that empty into Lake Ontario. In the deep waters of Lake Ontario, detritus is the common food source for the snails; while in streams periphyton becomes an important part of their diet. This experiment was designed to test the hypothesis that a diet of periphyton will lead to a higher growth rate compared to detritus. Benthic sediment was collected from 18 m depth in Lake Erie. Periphyton was grown on small rocks collected from Spring Run stream in central Pennsylvania. Eighty juvenile snails (0.6–1.0 mm in length) were placed individually into plastic cups and divided into four treatments: control snails that were fed Spirulina powder (standard lab diet), snails kept in lake sediment, snails reared on rocks with periphyton growth, and snails in a combination habitat of rock and lake sediment. After six weeks, the snails were measured again. Snails in the periphyton-only treatment had a significantly greater growth rate than snails in the remaining treatments. The other three treatments resulted in similarly low growth rates. These results suggest that the change in diet from detritus-based to periphyton-based as the snails move from a lake to a stream environment may result in higher individual and possibly population growth rates, and thus could increase their invasion success.
{"title":"A Periphyton-Based Diet Results in an Increased Growth Rate Compared to a Detritus-Based Diet in the Invasive New Zealand Mud Snail (Potamopyrgus antipodarum).","authors":"E. P. Levri, S. Landis, Brittany J. Smith","doi":"10.4003/006.035.0109","DOIUrl":"https://doi.org/10.4003/006.035.0109","url":null,"abstract":"Abstract: The invasive New Zealand mud snail, Potamopyrgus antipodarum (Gray 1843), has been present in the Laurentian Great Lakes for at least 20 years. Recently, the snail has spread to streams that empty into Lake Ontario. In the deep waters of Lake Ontario, detritus is the common food source for the snails; while in streams periphyton becomes an important part of their diet. This experiment was designed to test the hypothesis that a diet of periphyton will lead to a higher growth rate compared to detritus. Benthic sediment was collected from 18 m depth in Lake Erie. Periphyton was grown on small rocks collected from Spring Run stream in central Pennsylvania. Eighty juvenile snails (0.6–1.0 mm in length) were placed individually into plastic cups and divided into four treatments: control snails that were fed Spirulina powder (standard lab diet), snails kept in lake sediment, snails reared on rocks with periphyton growth, and snails in a combination habitat of rock and lake sediment. After six weeks, the snails were measured again. Snails in the periphyton-only treatment had a significantly greater growth rate than snails in the remaining treatments. The other three treatments resulted in similarly low growth rates. These results suggest that the change in diet from detritus-based to periphyton-based as the snails move from a lake to a stream environment may result in higher individual and possibly population growth rates, and thus could increase their invasion success.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":"35 1","pages":"65 - 69"},"PeriodicalIF":0.5,"publicationDate":"2017-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.035.0109","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45717997","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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