Journal of Molluscan Studies最新文献

{"title":"Shell shape as a potential predictor of age class in the invasive snail Lissachatina fulica","authors":"G. Marins, Angie Patiño-Montoya, R. Tidon","doi":"10.1093/mollus/eyad002","DOIUrl":"https://doi.org/10.1093/mollus/eyad002","url":null,"abstract":"\u0000 Understanding the life-history traits of invasive species can increase the effectiveness of eradication efforts and decrease costs. In the giant African snail Lissachatina fulica, one of the 100 worst invasive species on the planet, age structure can be an important indicator of invasiveness. Here, we associated variation in snail size with variation in weight and shell shape, in an effort to better understand the growth pattern in this species. Our study involved two components: we estimated the allometric relationship between weight and length in a natural population and monitored developmental variation in snail shape, weight, length and nutritional condition (condition factor) in a lab population. The weight and length growth patterns of the lab population were estimated independently using exponential regressions based on weekly measurements; shell shape was quantified using geometric morphometrics. In both populations, we found negative allometry between weight and length, suggesting that snail shells tend to elongate during growth. Geometric morphometrics confirmed this pattern and revealed that the change from a rounded to an elongated shell shape does not occur at a constant pace but during a specific growth interval (i.e. at a shell length of 55–65 mm), which is described in the literature as the size when the animal becomes hermaphroditic. Future studies should test whether the shape change reported here corresponds to the transition to the hermaphrodite age class, and with this in mind, we provide two simple morphological indexes that allow us to characterize shell shape as rounded or elongated. If shell size and shape are indicative of the transition to the hermaphroditism, then our findings can help to place individuals of L. fulica into appropriate age classes, and this will represent a useful baseline for development of eradication policies.","PeriodicalId":50126,"journal":{"name":"Journal of Molluscan Studies","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41878538","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}

{"title":"The mitochondrial genome ofIsognomon nucleusand mitogenomics of pteriomorphia (Bivalvia: Autobranchia)","authors":"Niklas Dreyer, Felipe Monteiro Gomes de Mattos, Dharmesh Jain, Chia-ling Fong, M. De Vivo, Y. Wen, Yu-Hsin Huang, J. Mwihaki, Hsin-Han Lee, P. Tsai, Y. Tsao, Benny Kwok Kan Chan, Isheng. J. Tsai, R. Machida, Tzi-Yuan Wang, John Wang","doi":"10.1093/mollus/eyad003","DOIUrl":"https://doi.org/10.1093/mollus/eyad003","url":null,"abstract":"","PeriodicalId":50126,"journal":{"name":"Journal of Molluscan Studies","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45384310","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}

{"title":"Holocene molluscan successions from southeastern Spain (Galera, Andalusia): a palaeoenvironmental framework and a palaeobiogeographic resource of the Granada UNESCO Geopark","authors":"Quentin Wackenheim, C. Richter, N. Limondin‑Lozouet, D. Wolf, F. García-Tortosa, Elisa Marzin, Luise Hofmann, J. Dabkowski, D. Faust","doi":"10.1093/mollus/eyac033","DOIUrl":"https://doi.org/10.1093/mollus/eyac033","url":null,"abstract":"\u0000 In Spain, Holocene deposits are widespread, and although they have been extensively investigated by quaternarists for several decades, their malacological content has remained scarcely studied. In the framework of a German–French–Spanish collaboration, alluvial and tufa sequences in the Baza Basin, Andalusia, Spain are analysed with a multidisciplinary approach, including the analysis of the molluscan successions. Holocene fossil molluscs of the studied sequences reveal a rich assemblage of 53 species, among which 33 are terrestrial. Between 10,000 and 9,000 cal. yr BP, the Galera succession indicates strong river dynamics that prevented the establishment of adjacent terrestrial habitats. The Early to Middle Holocene transition reflects the continuity of humid environments. The Middle Holocene fauna reveals a decrease in humidity accompanied by slight evidence of drier habitats in the near periphery of the floodplain/tufa deposits from 5,900 cal. yr BP onwards. Late Holocene deposits (around 3,000 to 300 cal. yr BP) point to dry and open biotopes indicated by the appearance of xero-resistant and mesophilous gastropods. The palaeoenvironmental reconstruction inferred from the malacocenoses allows discussing local to regional responses of the malacofauna to environmental changes and is consistent with past regional environmental and climatic trends identified in southeastern Spain. The fossil record at Galera offers new evidence to question and clarify the modern range of endemic taxa whose distributions are fragmented. By following a ‘conservation paleobiology’ approach, the analysis of the mollusc fossil record at Galera provides (1) baselines to determine the natural variability of ecosystems and their response to environmental changes, (2) data to discuss and clarify species distribution evolution and (3) arguments to support conservation priorities.","PeriodicalId":50126,"journal":{"name":"Journal of Molluscan Studies","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42884957","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}

{"title":"Transcriptomic landscape of the kleptoplastic sea slug <i>Elysia viridis</i>","authors":"Manuel Mendoza, Sara Rocha, Jesús Troncoso, David Posada, Carlos Canchaya","doi":"10.1093/mollus/eyad001","DOIUrl":"https://doi.org/10.1093/mollus/eyad001","url":null,"abstract":"","PeriodicalId":50126,"journal":{"name":"Journal of Molluscan Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135995361","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}

{"title":"Living in solitude or building reefs: ecophenotypic variation of the vermetid Petaloconchus varians revealed by mitochondrial DNA analysis","authors":"A. Breves, Thiago S. De Paula, Paula Spotorno, M. R. Fernandes, G. Lôbo‐Hajdu, A. D. Pimenta","doi":"10.1093/mollus/eyac030","DOIUrl":"https://doi.org/10.1093/mollus/eyac030","url":null,"abstract":"\u0000 This study aimed to investigate whether the marine snails Petaloconchus varians (d'Orbigny, 1839) and Petaloconchus myrakeenae Absalão & Rios, 1987 from southeastern Brazil are conspecific. Both species were described from Rio de Janeiro, and they diverge mainly in their growth forms (i.e. gregarious for P. varians and solitary for P. myrakeenae). Examination of shell features, operculum, radula and anatomic details revealed no differences between the species. Analysis of partial cytochrome c oxidase subunits I (CO1) sequences showed that all Petaloconchus samples from Rio de Janeiro clustered into a single clade, which included specimens from the Caribbean (Venezuela). In addition, a genetic differentiation test showed that the analysed populations are structured and the species likely originated in the Caribbean and has undergone significant population expansion. We conclude that P. myrakeenae is a junior synonym of P. varians and provide a morphological redescription of the latter. Furthermore, we argue that different growth forms of P. varians are ecophenotypes, apparently influenced by wave action and water temperature. Tests should be conducted to confirm this hypothesis and to evaluate the impact of other parameters on the plasticity of growth forms, such as food supply and habitat heterogeneity.","PeriodicalId":50126,"journal":{"name":"Journal of Molluscan Studies","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49588638","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}

{"title":"Closing the gap: a new phylogeny and classification of the chemosymbiotic bivalve family Lucinidae with molecular evidence for 73% of living genera","authors":"John D. Taylor, E. Glover, B. Yuen, Suzanne T. Williams","doi":"10.1093/mollus/eyac025","DOIUrl":"https://doi.org/10.1093/mollus/eyac025","url":null,"abstract":"\u0000 New molecular phylogenies of the chemosymbiotic bivalve family Lucinidae, using 18S rRNA, 28S rRNA and cytochrome b genes, include species from genera not previously analysed. Notable additions from Myrteinae are sequences from Rostrilucina, Solelucina and Taylorina species, species of Ustalucina, Gonimyrtea from Leucosphaerinae and additional species of Ctena, Codakia, Lucinoma and Divalucina from Codakiinae. New sequences of Lucininae include the type species of Parvilucina (P. tenuisculpta), Liralucina, Falsolucinoma, Easmithia, Jallenia, Radiolucina and Cardiolucina as well as samples of Loripes orbiculatus from multiple localities. Five major clades, defined as subfamilies, are recognized: Pegophyseminae, Myrteinae, Leucosphaerinae, Codakiinae and Lucininae. Two branches, Fimbriinae and Monitilorinae, are represented by single species. Pegophyseminae are an extremely long-branched group with a sister-group relationship to Leucosphaerinae, while Codakiinae are a sister clade to the Lucininae. In various gene trees, the position of Myrteinae is unstable in relation to Pegophyseminae + Leucosphaerinae, Monitilorinae and Fimbriinae. The Myrteinae are not well resolved, with an ambiguous correlation of molecular and morphological characters. Codakiinae now include Divalucina cumingi, shown to be related to Lucinoma rather than Divaricella and Divalinga of the Lucininae. Leucosphaerinae are a well-supported clade but morphologically disparate, with the positions of Gonimyrtea and Callucina unresolved. Several molecularly distinct subclades are recognized within the Lucininae, especially the Lucinisca, Loripes and Parvilucina groups. Parvilucina species are paraphyletic with P. tenuisculpta, the type species, distinct from the western Atlantic species. Codakia, Ctena and Pegophysema have pan-tropical distributions with former connections disrupted by vicariant events of the closure of the eastern Tethyan and Central American Seaways. Species of Radiolucina, Pleurolucina and Lucinisca are present on either side of the Isthmus of Panama. A new classification of the 96 living lucinid genera is presented, providing a framework for future studies of systematics, ecology, biogeography and bacterial symbioses.","PeriodicalId":50126,"journal":{"name":"Journal of Molluscan Studies","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41393539","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}

{"title":"Improving external shell volume estimation in snails using landmark-based size measurements","authors":"T. R. Osborne, S. Stehman","doi":"10.1093/mollus/eyac032","DOIUrl":"https://doi.org/10.1093/mollus/eyac032","url":null,"abstract":"\u0000 Shell images in digital collections and publications enable taxonomically, geographically and morphologically broad approaches to studying gastropod body size. Because traditional linear size measurements are not directly comparable across morphologically disparate taxa, we propose a transition to landmark-based size measurements, which are less sensitive to shape differences. Traditional and landmark-based size measurements were compared using two study systems: 36 specimens of diplommatinid micromolluscs from the Belau archipelago and 66 marine, freshwater and terrestrial gastropod shells from the Roosevelt Wild Life Collections (RWLC; housed at the State University of New York College of Environmental Science and Forestry, Syracuse, NY, USA). Belau diplommatinids were used to assess the effectiveness of size measurements when comparing confamilial specimens. This study system was most sensitive to methodologically introduced variance. RWLC shells were used to assess measurement effectiveness when comparing morphologically disparate taxa. A total of seven size variables measured from 2D images were compared, three variables based on interlandmark distances and four based on linear shell dimensions. Landmark-based size measurements were centroid size, a proposed new measurement dubbed size adjusted mean (SAM) and its rescaled version, SAM1/3. The linear dimension-based measurements were maximum, mean and geometric mean of shell height and width, as well as conical volume (volume of a cone with similar dimensions to specimen). Measurement accuracy was assessed by regressing external shell volume against each size measurement. For Belau diplommatinids, centroid size and maximum shell dimension most accurately predicted external shell volume. For RWLC shells, conical volume followed by SAM1/3 and geometric mean shell dimension were the most accurate predictors. Repeatability was assessed by computing % measurement error (%ME). Maximum shell dimension was most repeatable (%ME = 4.19%) for Belau diplommatinids, followed by centroid size (7.76%). Conical volume (%ME = 0.0039%) and maximum shell dimension (0.0073%) were most repeatable for RWLC shells. In both study systems, SAM1/3 was the land-mark-based size measurement most robust to missing landmarks, followed by centroid size. Based on these findings, we recommend using centroid size to compare congeneric or confamilial specimens and using conical volume to compare morphologically or taxonomically disparate specimens. However, conical volume could not be calculated when shell height or width data are unavailable. In such cases, we recommend comparing morphologically disparate shells using SAM1/3.","PeriodicalId":50126,"journal":{"name":"Journal of Molluscan Studies","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46389851","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}

{"title":"Egg production in Arion vulgaris: density dependence in A. vulgaris and interspecific effects of Limax maximus","authors":"J. Watz, S. Johansson, D. Nyqvist","doi":"10.1093/mollus/eyac026","DOIUrl":"https://doi.org/10.1093/mollus/eyac026","url":null,"abstract":"","PeriodicalId":50126,"journal":{"name":"Journal of Molluscan Studies","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48903892","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}

{"title":"Effect of culture depth on the shell thickness of the blue mussel Mytilus edulis: a practical case study comparing direct and indirect methods of measurement","authors":"D. Gallardi, H. Murray","doi":"10.1093/mollus/eyac024","DOIUrl":"https://doi.org/10.1093/mollus/eyac024","url":null,"abstract":"\u0000 Mytilus species have a fundamental role in coastal environments and constitute an important aquaculture resource. Their shell has a protective function and is affected by multiple factors, such as the size of the animal, density, environmental characteristics and presence of predators. It is crucial to accurately estimate shell thickness in order to understand the effects of the ever-changing environment on mussel physiology, morphology and ecology. This study compares a newly developed direct method for measuring shell thickness, using scanning electron microscopy (SEM), and a widely used indirect method (shell thickness index, STI), in the context of a practical case study of the blue mussel Mytilus edulis. In this study, STI did not appear as highly correlated to direct thickness measurement as in previous studies. This study also showed a weaker relationship between measured shell length and STI. In the case study, assessing the effect of culture depth on M. edulis growth and condition, STI showed a significant variation with depth, while SEM measured thickness did not. Therefore, the choice to use STI vs direct measurement of shell thickness drastically changed the results and interpretation of the case study. This work highlights the importance of a carefully designed method for measuring shell thickness and emphasizes that, before application, indirect methods should be quality controlled for the population studied. However, when high precision is needed for shell thickness measurements the application of SEM-based techniques may be necessary. This is the first study where SEM-based techniques have been used to measure shell thickness in M. edulis.","PeriodicalId":50126,"journal":{"name":"Journal of Molluscan Studies","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42665329","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}

{"title":"Correction to: Exceptional among the exceptional: a new species of Stenogyropsis Möllendorff, 1899 (Eupulmonata: Camaenidae), with a review of the free last whorl in terrestrial gastropods","authors":"Zheyu Chen, B. Huang, B. Páll‐Gergely","doi":"10.1093/mollus/eyac022","DOIUrl":"https://doi.org/10.1093/mollus/eyac022","url":null,"abstract":"","PeriodicalId":50126,"journal":{"name":"Journal of Molluscan Studies","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47139150","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}