Malacologia最新文献

{"title":"Assessing Species Boundaries in the Freshwater Snail Family Physidae Using Coalescent-Based Delimitation Methods","authors":"Bianca Sartini do Espirito Santo, M. Rossi, Ximena Maria Constanza Ovando, S. D’ávila","doi":"10.4002/040.065.0107","DOIUrl":"https://doi.org/10.4002/040.065.0107","url":null,"abstract":"ABSTRACT A common issue for several freshwater snail families is the fact that, for some genera, the criteria for species delimitation are scarce, subjected to intraspecific and ontogenetic variation, or insufficiently discrete to allow a clear distinction between species. For these genera, the use of molecular approaches is decisive in recognizing valid species. Herein, we applied coalescent methods to delimit evolutionary significant units (ESUs) in Physidae. We used 496 sequences of the mitochondrial cytochrome oxidase subunit I (COI) gene available in GenBank, ascribed to six genera and 25 nominal species, and the algorithms GMYC (General Mixed Yule-Coalescent) with two criteria (single-threshold and multiple-threshold), PTP (Poisson Tree Process), and mPTP (multi-rate Tree Poisson Process). The method that presented the best performance was the mPTP. This method showed a higher frequency of taxonomic species recovery and has delimited a lower number of ESUs (25 ESUs from a dataset attributed to 25 nominal species). Physidae is a family of freshwater snails that presents several issues related to the recognition of species boundaries. Herein, the use of coalescent delimitation methods allowed us to address important taxonomic questions, opening new avenues for future taxonomic research. Our findings have shown that the morphological operational criteria used to delimit several valid species fall within the limits of intraspecific variability, demonstrating taxonomic inflation within this family. Our results also demonstrated the presence of cryptic diversity under the nominal species Physella acuta (Draparnaud, 1805), Beringophysa jennessi (Dall, 1919), Physella pomilia (Conrad, 1834), and Physella gyrina (Say, 1821).","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45660640","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":"Pronounced Mitochondrial DNA Population Genetic Structure in a Brooding Coastal Marine Invertebrate","authors":"Xiangbo Guo, K. Wei, Ruo-Jin Yan, J. Gardner","doi":"10.4002/040.065.0108","DOIUrl":"https://doi.org/10.4002/040.065.0108","url":null,"abstract":"ABSTRACT Analyses of phylogeographic and population genetic structure of marine species with large population sizes, low fecundity, larval brooding, and limited dispersal such as the New Zealand flat oyster, Ostrea chilensis Küster, 1844, permit testing of the effects of historical and contemporary processes affecting patterns of coastal genetic differentiation and diversity. Analyses of DNA sequences from two mitochondrial DNA regions (COI, Cyt-b) compiled from O. chilensis individuals from 14 localities revealed a pronounced structure with three genetic clusters [Hauraki Gulf (HG); North; South] being resolved. These results suggest that historical processes have contributed to patterns of regional separation that have in turn contributed to regional genetic differences that are still observable today. Divergence time estimates of HG from North+South (1.97 Ma) and of North from South (0.36 Ma) indicate that O. chilensis from these regions represent evolutionarily significant units that evolved separately and rapidly in the early to middle Pleistocene. Analyses revealed no obvious periods of population expansion within any of the regions. These results contribute to a better understanding of how historical factors can result in pronounced mitochondrial DNA patterns of contemporary genetic structure and show how key life-history characteristics, e.g., larval brooding, can contribute to phylogeographic structure in coastal marine invertebrates.","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45844922","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":"Aneuploidy in the Pearl Oyster Pinctada radiata (Leach, 1814): Evidence for Nonrandom Chromosome Loss and Gain in Marine Bivalves","authors":"Zenaba Khatir, Zainab Hizam, B. Lyons, A. Leitão","doi":"10.4002/040.065.0105","DOIUrl":"https://doi.org/10.4002/040.065.0105","url":null,"abstract":"ABSTRACT Aneuploidy, or presence of an abnormal number of chromosomes, has been commonly observed in marine bivalves. This phenomenon has also been shown to be negatively correlated with growth and survival rates in several species of oysters and clams. The impact of pollutants on the aneuploidy level in bivalves has also been previously demonstrated. Over the past two decades, evidence of nonrandom chromosomal loss has been demonstrated, with the identification of the missing chromosomes in aneuploid karyotypes reported in several species. The results have shown that only a few pairs were preferentially affected by the loss of one homologue chromosome in different species of oysters and clams. Recently, during the genotoxicity assessment of the marine environment in Qatar using the pearl oyster Pinctada radiata (Leach, 1814) as model and surrogate species, we observed hypodiploid and hyperdiploid karyotypes. Hyperdiploidy was more frequent, which is highly uncommon in bivalves. The identification of the extra and missing chromosomes in aneuploid cells showed that pairs 4, 5, 12, and 13 were found to be more susceptible than others in having an extra individual chromosome. The same set of pairs showed a tendency to lose one homologue chromosome. Several hypotheses on the preferential chromosomal susceptibility in bivalves, in general, are discussed.","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47252066","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":"Phylogenetic Systematics and Distribution of Pomacea sordida (Swainson, 1823) and Pomacea intermedia (Férussac in Quoy & Gaimard, 1825) (Caenogastropoda: Ampullariidae)","authors":"Kevin P. Barbosa, K. Hayes, Roberto do V. Vilela, H. S. Barbosa, C. Marchi, S. Thiengo","doi":"10.4002/040.065.0101","DOIUrl":"https://doi.org/10.4002/040.065.0101","url":null,"abstract":"ABSTRACT In contrast to their relative ecological and economic importance, many species of Ampullariidae remain poorly studied, and lack robust data needed to clearly circumscribe the species or understand their biogeographic distributions. A few, e.g., Pomacea maculata Perry, 1810 and P. canaliculata (Lamarck, 1822), have been well studied, in part because of their notorious reputations as invasive pests. Unfortunately, beyond broad phylogenetic studies, we know little about the relationships and distributions of the dozen or so other species with which these two well-known ampullariids have and continue to be confused. The ability to delimit such species not only has implications for invasion biology, but also for conservation of native species. The ampullariid Pomacea sordida (Swainson, 1823) is endemic to the state of Rio de Janeiro, Brazil. Recent molecular analyses revealed that several populations previously referred to as P. sordida, belong to another genetically distinct species, Pomacea intermedia (Férussac in Quoy & Gaimard, 1825), currently regarded as a junior synonym of P. sordida. To evaluate the validity of this previous study, we examined all of the material identified as P. sordida from the collection of the Institute Oswaldo Cruz and carried out additional surveys across the known distribution of these species. Phylogenetic analyses of COI sequences from 96 snails sequenced for this study, along with additional sequences from GenBank, recovered P. sordida and P. intermedia as sister taxa in a clade sister to P. flagellata (Say, 1829) and P. patula (Reeve, 1856). Surveys of aquatic habitats in the state of Rio de Janeiro recovered both species in allopatric populations with P. sordida primarily restricted to seven sites in the southwestern part of the state, whereas P. intermedia occurred in six sites in the central part of the state, northeast of P. sordida populations. Although cursory examination of male reproductive anatomy of these two species does not provide taxonomically informative characters that allow delineation of these two species, other traits e.g., juvenile shell characters, egg morphology, and kidney shape and arrangement, appear to be informative and provided necessary data to rescue P. intermedia from synonymy with P. sordida.","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47336177","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":"An Integrative Approach for the Identification of Native and Exotic Lymnaeids from Brazil","authors":"C. Medeiros, Larissa Lopes Silva Scholte, Paula Cristina Marques Cardoso, J. Pointier, A. Rumi, Ivana Helena Rocha Oliveira, P. M. de Souza, S. D’ávila, G. Rosenberg, O. Santos Carvalho, R. Caldeira","doi":"10.4002/040.065.0102","DOIUrl":"https://doi.org/10.4002/040.065.0102","url":null,"abstract":"ABSTRACT Many freshwater snail species of the family Lymnaeidae are known to act as intermediate hosts of Fasciola hepatica, the causative agent of fasciolosis, a parasitic disease of great veterinary and medical importance. Morphological identification of lymnaeid species is based on characteristics of shell, reproductive and renal systems. However, such identification is challenging due to interspecific similarity, which is particularly evident among the species Galba viator, G. cubensis, and G. truncatula. To overcome these difficulties, we used molecular markers and a morphological approach applied to specimens from Brazil to compare the data obtained with type specimens, topotypes, and other lymnaeid species. We used PCR-RFLP with MboII, HpaII, and AluI enzymes directed to the ITS2-rDNA region, which allowed differentiation among Pseudosuccinea columella, Pectinidens diaphanus, G. viator, G. cubensis, and G. truncatula when morphological characterization is inconclusive. These results allowed us to report for the first time the occurrence of G. cubensis and G. truncatula in the state of Minas Gerais, Brazil. We also performed phylogenetic analyses using 16S mtDNA sequences, which corroborated the PCR-RFLP results. The molecular techniques used in this study aimed to support the morphological identification of Lymnaeidae populations from Brazil and have proven to be a helpful tool when morphological analysis does not support confident identification at the species level.","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41746073","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":"Characterization of Neurodevelopment in Larvae of the Protobranch Acila insignis (Gould, 1861) in Order to Reconstruct the Last Common Ancestor of Bivalves","authors":"O. Yurchenko, V. Dyachuk","doi":"10.4002/040.064.0207","DOIUrl":"https://doi.org/10.4002/040.064.0207","url":null,"abstract":"ABSTRACT Understanding aspects of development in animals posessing certain “ancestral” traits can provide key insights into the evolution of various larval forms of invertebrates. Little is presently known concerning the neurodevelopment of Protobranchia, a group of bivalve mollusks. We are first to demonstrate that neurogenesis of the pericalymma larvae of the protobranch Acila insignis differs dramatically from that of the larval nervous system of autobranchia species as revealed by serotonin (5-HT) and FMRFamide antibodies and whole-mount confocal microscopy. Early in the development of pericalymma, two and then three flask-shaped cells immunopositive for 5-HT appear in the apical organ (AO). Later on, in mid-stage larvae, cells immunostained for FMRFamide appear in the dorsal portion of the larva, including a weak signal in the AO. Immediately prior to metamorphosis, the larval FMRFamide-ergic nervous system consists of a single cell in the AO together with several non-sensory cells in the posterior and dorsal regions. No neuronal connections between the larval neuronal cell groups were observed. However, despite the obvious differences in early neurogenesis, there are clear neuromorphological similarities of the studied protobranch species to (1) spiralians (by the presence of an AO), (2) certain trochozoans (by peripheral cells containing FMRFamide) and (3) bivalve mollusks (by AO including three flask-shaped cells revealed by immunostaining for 5-HT). Thus, the nervous system of A. insignis is similar to that of other mollusks and lophotrochozoans due to the presence of an AO, while differing from all the studied groups in other characters (location and composition of FMRFamide cells). Morphological and molecular development of key protobranch taxa need to be further studied in order to infer the evolution of mollusks.","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45000181","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":"Northeastern Pacific Octopus Beak Shape for Species-Level Detection","authors":"Mariana Díaz-Santana-Iturrios, Viridiana Zepeda-Benitez, Renata Pacheco-Ovando, Claudio F. Cornejo, J. Cerda, C. Salinas-Zavala, J. Granados-Amores","doi":"10.4002/040.064.0202","DOIUrl":"https://doi.org/10.4002/040.064.0202","url":null,"abstract":"ABSTRACT Cephalopods have upper and lower chitinous beaks, and their shape can be used to identify species. However, the morphological attributes of beaks are commonly obtained from sources that contain little information on shape, compromising the determination of taxa. Thus, in this study, we used geometric morphometrics to analyze inter-specific differences in beak shape of six octopus species from the northeastern Pacific. We found evidence of species-level discrimination according to upper and lower beak shape. In addition, we provided a detailed description of these chitinous structures for each species, and we developed a key to identify the species based on upper and lower beak shape. The inter-specific morphological variation of beaks of the octopuses evaluated in our study could be the result of adaptive processes related to habitat and feeding habits. The information generated in our study can be used for identification of six octopus species from the northeastern Pacific based on upper and lower beak shape.","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42953254","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":"Species Synonymies in the Deep-Sea Wood-Boring Bivalve Genus Xyloredo (Mollusca: Xylophagaidae)","authors":"J. Voight","doi":"10.4002/040.064.0201","DOIUrl":"https://doi.org/10.4002/040.064.0201","url":null,"abstract":"ABSTRACT Sequences of specimens of the xylophagaid genus Xyloredo revealed minimal molecular divergence among ten specimens from the North and South Atlantic and the northeast and southwest Pacific Oceans. Although genetically identical, the valves of two New Zealand specimens differ dramatically, likely due to their three-fold size difference. Comparable size differences among the type series of X. nooi, X. naceli and X. ingolfia and their disjunct distributions may have contributed to their recognition as distinct species; the species are synonymized here as Xyloredo nooi. The flattened umbonal-ventral ridge, the fold inside the posterior shell, the two elongate calcified strips of the mesoplax embedded in a periostracal anterior adductor cover and a two-parted siphon with the simple, separate openings are unique to members of Xyloredo. Molecular sequencing of the Japanese X. teramachii is needed to test if it is distinct.","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46194348","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":"Minimally Invasive DNA Sampling by Hemolymph Extraction Minimizes Risk to Freshwater Mussels: The Case of Endangered Unio crassus Philipsson, 1788 (Bivalvia: Unionidae)","authors":"I. Richling, C. Krause","doi":"10.4002/040.064.0212","DOIUrl":"https://doi.org/10.4002/040.064.0212","url":null,"abstract":"ABSTRACT Research on endangered species is important for species conservation. Some lines of conservation research require tissue or fluids so that molecular data can be obtained. Thus, there is an increasing demand for methods of DNA sampling in endangered species that minimize harm to live animals. This especially concerns such highly threatened and protected freshwater mussels as the thick-shelled river mussel Unio crassus. With two different field experiments in Germany under natural conditions, the short- and long-term survival of Unio crassus after hemolymph extraction from the foot tissue was evaluated. We detected no negative effects in individuals of over 40 mm shell length and older than five years. We also followed some individuals for up to three years after treatment and detected no harm to these individuals. DNA quality was high and proved fully suitable for single-gene sequencing (COI) and microsatellite analyses.","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44961183","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 Origin of Malacologia – the International Journal of Malacology – and Jack Burch (12 August 1929 – 3 June 2021)","authors":"G. Davis","doi":"10.4002/040.064.0213","DOIUrl":"https://doi.org/10.4002/040.064.0213","url":null,"abstract":"","PeriodicalId":49895,"journal":{"name":"Malacologia","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45354779","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}