Journal articles: 'Mollusca, classification'

1

Smith, Martin R. "Mouthparts of the Burgess Shale fossils Odontogriphus and Wiwaxia : implications for the ancestral molluscan radula." Proceedings of the Royal Society B: Biological Sciences 279, no. 1745 (August 22, 2012): 4287–95. http://dx.doi.org/10.1098/rspb.2012.1577.

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The Middle Cambrian lophotrochozoans Odontogriphus omalus and Wiwaxia corrugata have been interpreted as stem-group members of either the Mollusca, the Annelida, or a group containing Mollusca + Annelida. The case for each classification rests on the organisms' unusual mouthparts, whose two to three tooth-rows resemble both the molluscan radula and the jaws of certain annelid worms. Despite their potential significance, these mouthparts have not previously been described in detail. This study examined the feeding apparatuses of over 300 specimens from the 505-million-year-old Burgess Shale, many of which were studied for the first time. Rather than denticulate plates, each tooth row comprises a single axial tooth that is flanked on each side by eight to 16 separate shoehorn-shaped teeth. Tooth rows sat on a grooved basal tongue, and two large lobes flanked the apparatus. New observations—the shape, distribution and articulation of the individual teeth, and the mouthparts' mode of growth—are incompatible with an annelid interpretation, instead supporting a classification in Mollusca. The ancestral molluscan radula is best reconstructed as unipartite with a symmetrical medial tooth, and Odontogriphus and Wiwaxia as grazing deposit-feeders.

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Yochelson, Ellis L. "Definition of Mollusca II." Notes for a Short Course: Studies in Geology 13 (1985): 9–12. http://dx.doi.org/10.1017/s0271164800001056.

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Definition and classification probably rank second only to marriage as a source of controversy, but it is not in that spirit in which I want to write; I only want to show that there may be more than one viewpoint about Mollusca. Problems of definition and classification are different. Workers may agree on the defintions of phyla and classes, yet disagree on their arrangement. Definition and classification each have two separate and distinct phases: the work itself on developing a concept; and the general acceptance of this concept. New ideas by their very nature go against prevailing opinion; it is not a new idea itself which is the critical feature as is its acceptance. Acceptance of definition and/or classification tends to be a passive process and most teachers are content to quote uncritically that which is in the latest textbook.

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Walker, J. C. "Classification of Australian buliniform planorbids (Mollusca: Pulmonata)." Records of the Australian Museum 40, no. 2 (May 26, 1988): 61–89. http://dx.doi.org/10.3853/j.0067-1975.40.1988.151.

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4

Lindberg, David R. "Aplacophorans, Monoplacophorans, Polyplacophorans, Scaphopods: the Lesser Classes." Notes for a Short Course: Studies in Geology 13 (1985): 230–47. http://dx.doi.org/10.1017/s0271164800001202.

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The “primitive,” “minor” or “lesser” classes of the Mollusca comprise four groups that are typically recognized at the class level in most classification schemes. These classes are: (1) the Aplacophora, (2) the Monoplacophora, (3) the Polyplacophora, and (4) the Scaphopoda. Members of these classes are bilaterally symmetrical and typically possess a ventral muscular foot and a dorsal epidermal tissue (the mantle) that secretes a calcareous covering. Between these two structures lie the viscera. The space that develops between the mantle and the foot of the mollusc is referred to as the mantle cavity. Into this cavity open the ducts from the excretory, alimentary, and reproductive systems; gills are also typically located in this space. The anterior end of these molluscs is marked by a muscular head in which most of the ganglia are concentrated. The mouth is situated ventrally and opens internally into the pharynx which contains, at its anterior end, the radula and its associated musculature and support structures. The intestinal tract is typically arranged in complex loops.

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Hickman, Carole S., and David R. Lindberg. "Perspectives on Molluscan Phylogeny." Notes for a Short Course: Studies in Geology 13 (1985): 13–16. http://dx.doi.org/10.1017/s0271164800001068.

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Achieving consensus on the definition of the Mollusca is fortunately not prerequisite to the exercise of taxonomic classification and phylogenetic analysis. Definitions emerge from analysis, and it is therefore germane to consider the ways in which analytic procedures and underlying assumptions may affect growth of knowledge of the Mollusca.

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Hogg, Jabez. "The Lingual Membraneof Mollusca, and its Value in Classification." Journal of Microscopy 145, no. 2 (February 1987): 93–104. http://dx.doi.org/10.1111/j.1365-2818.1987.tb04727.x.

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Carter, Joseph G., and George R. Clark. "Classification and Phylogenetic Significance of Molluscan Shell Microstructure." Notes for a Short Course: Studies in Geology 13 (1985): 50–71. http://dx.doi.org/10.1017/s0271164800001093.

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Like most classifications of molluscan shell microstructure published during the past 25 years (e.g., MacClintock, 1967; Kobayashi, 1964, 1971; Taylor, Kennedy and Hall, 1969, 1973; Grégoire, 1972a), the present one is based largely on Bøggild's (1930) monographic work, redefined from a modern perspective of combined light and scanning electron microscopy. However, this is the first attempt to integrate shell microstructure terminology for mollusks with that employed by students of bryozoan and brachiopod shell microstructure (e.g., Williams, 1968a,b, 1970, 1973; Williams and Wright, 1970; Armstrong 1968, 1969; Sandberg, 1971, 1977; Brunton, 1972; MacKinnon, 1974, 1977; MacKinnon and Williams, 1974; Iwata, 1981, 1982). An integration of nomenclatorial schemes is desirable for purposes of interphylum comparison, and is presently needed because there is considerable overlap and inconsistency in the application of microstructural terminology even within single molluscan classes. The present synthesis of shell microstructure nomenclature is possible primarily because of the extensive data base of invertebrate shell mineralogy, microstructure and especially ultrastructure published in more than 300 references in the past 15 years. To these data, the authors have contributed original information of shell mineralogy and microstructure for scores of Recent and fossil mollusks, brachiopods and bryozoans, with a clear emphasis on bivalved mollusks. Many inadequately described microstructure terms have been reanalyzed during the course of this study, either by examining species cited in the literature, or by using closely related species. Perhaps because they are better studied, but probably for other reasons as well, the diversity of molluscan shell microstructures is considerably greater than that of brachiopods and bryozoans combined (Carter, 1979). Consequently, most of the present nomenclature is based on mollusks, and only three of the major microstructural arrangements described in this guide (crossed bladed, semi-nacreous and semi-foliated) were known first in brachiopods or bryozoans and later recognized in molluscs.

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TËMKIN, ILYA. "Morphological perspective on the classification and evolution of Recent Pterioidea (Mollusca: Bivalvia)." Zoological Journal of the Linnean Society 148, no. 3 (November 2006): 253–312. http://dx.doi.org/10.1111/j.1096-3642.2006.00257.x.

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TAYLOR, JOHN D., EMILY A. GLOVER, LISA SMITH, PATRICIA DYAL, and SUZANNE T. WILLIAMS. "Molecular phylogeny and classification of the chemosymbiotic bivalve family Lucinidae (Mollusca: Bivalvia)." Zoological Journal of the Linnean Society 163, no. 1 (August 19, 2011): 15–49. http://dx.doi.org/10.1111/j.1096-3642.2011.00700.x.

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VON SALVINI-PLAWEN, L. "CONTRIBUTIONS TO THE MORPHOLOGICAL DIVERSITY AND CLASSIFICATION OF THE ORDER CAVIBELONIA (MOLLUSCA: SOLENOGASTRES)." Journal Molluscan Studies 70, no. 1 (February 1, 2004): 73–93. http://dx.doi.org/10.1093/mollus/70.1.73.

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KŘÍŽ, JIŘÍ. "ORIGIN, EVOLUTION AND CLASSIFICATION OF THE NEW SUPERORDER NEPIOMORPHIA (MOLLUSCA, BIVALVIA, LOWER PALAEOZOIC)." Palaeontology 50, no. 6 (November 2007): 1341–65. http://dx.doi.org/10.1111/j.1475-4983.2007.00720.x.

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12

Stöger, I., J. D. Sigwart, Y. Kano, T. Knebelsberger, B. A. Marshall, E. Schwabe, and M. Schrödl. "The Continuing Debate on Deep Molluscan Phylogeny: Evidence for Serialia (Mollusca, Monoplacophora + Polyplacophora)." BioMed Research International 2013 (2013): 1–18. http://dx.doi.org/10.1155/2013/407072.

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Molluscs are a diverse animal phylum with a formidable fossil record. Although there is little doubt about the monophyly of the eight extant classes, relationships between these groups are controversial. We analysed a comprehensive multilocus molecular data set for molluscs, the first to include multiple species from all classes, including five monoplacophorans in both extant families. Our analyses of five markers resolve two major clades: the first includes gastropods and bivalves sister to Serialia (monoplacophorans and chitons), and the second comprises scaphopods sister to aplacophorans and cephalopods. Traditional groupings such as Testaria, Aculifera, and Conchifera are rejected by our data with significant Approximately Unbiased (AU) test values. A new molecular clock indicates that molluscs had a terminal Precambrian origin with rapid divergence of all eight extant classes in the Cambrian. The recovery of Serialia as a derived, Late Cambrian clade is potentially in line with the stratigraphic chronology of morphologically heterogeneous early mollusc fossils. Serialia is in conflict with traditional molluscan classifications and recent phylogenomic data. Yet our hypothesis, as others from molecular data, implies frequent molluscan shell and body transformations by heterochronic shifts in development and multiple convergent adaptations, leading to the variable shells and body plans in extant lineages.

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Keys, Jennifer L., and John M. Healy. "Relevance of sperm ultrastructure to the classification of giant clams (Mollusca, Cardioidea, Cardiidae, Tridacninae)." Geological Society, London, Special Publications 177, no. 1 (2000): 191–205. http://dx.doi.org/10.1144/gsl.sp.2000.177.01.11.

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14

ZHANG, ZHI-QIANG. "Animal biodiversity: An introduction to higher-level classification and taxonomic richness." Zootaxa 3148, no. 1 (December 23, 2011): 7. http://dx.doi.org/10.11646/zootaxa.3148.1.3.

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For the kingdom Animalia, 1,552,319 species have been described in 40 phyla in a new evolutionary classification. Among these, the phylum Arthropoda alone represents 1,242,040 species, or about 80% of the total. The most successful group, the Insecta (1,020,007 species), accounts for about 66% of all animals. The most successful insect order, Coleoptera (387,100 species), represents about 38% of all species in 39 insect orders. Another major group in Arthropoda is the class Arachnida (112,201 species), which is dominated by the mites and ticks (Acari 54,617 species) and spiders (43,579 species). Other highly diverse arthropod groups include Crustacea (66,914 species), Trilobitomorpha (19,606 species) and Myriapoda (11,885 species). The phylum Mollusca (117,358 species) is more diverse than other successful invertebrate phyla Platyhelminthes (29,285 species), Nematoda (24,783 species), Echinodermata (20,509 species), Annelida (17,210 species) and Bryozoa (10,941 species). The phylum Craniata, including the vertebrates, represents 64,832 species (for Recent taxa, except for amphibians): among these 7,694 described species of amphibians, 31,958 species of “fish” and 5,750 species of mammals.

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REYNOLDS, PATRICK D. "The phylogeny and classification of Scaphopoda (Mollusca): an assessment of current resolution and cladistic reanalysis." Zoologica Scripta 26, no. 1 (January 1997): 13–21. http://dx.doi.org/10.1111/j.1463-6409.1997.tb00406.x.

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Richardot-Coulet, M., E. Castella, and C. Castella. "Classification and succession of former channels of the french upper rhone alluvial plain using mollusca." Regulated Rivers: Research & Management 1, no. 2 (April 1987): 111–27. http://dx.doi.org/10.1002/rrr.3450010203.

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17

Ridgway, S. A., D. G. Reid, J. D. Taylor, G. M. Branch, and A. N. Hodgson. "A cladistic phylogeny of the family Patellidae (Mollusca: Gastropoda)." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 353, no. 1375 (October 29, 1998): 1645–71. http://dx.doi.org/10.1098/rstb.1998.0316.

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A phylogenetic hypothesis for the patellid limpets is reconstructed by cladistic analysis of morphological characters from 37 species, representing all but one of the living members of the family. Characters included in the analysis are derived from shell shape and microstructure, headfoot and pallial complex, radula and sperm. The species fall into four clades, providing the basis for a new phylogenetic classification into four monophyletic genera: Helcion (four species; southern Africa), Cymbula (eight species; southern Africa, eastern Atlantic, southern Indian Ocean), Scutellastra (17 species; southern and southwestern Africa, Australia, Indo–West Pacific, Eastern Pacific) and Patella (nine species; northeastern Atlantic and Mediterranean). The analysis suggests sister–group relationships between Helcion and Cymbula , and between Scutellastra and Patella . In combination with present–day patterns of geographical distribution, this phylogenetic hypothesis is used to discuss the historical biogeography of the Patellidae. Scutellastra may have originated in southern Africa and dispersed across the Pacific, or alternatively may be a primitively Tethyan group. Both Helcion and Cymbula appear to have originated in southern Africa, but three Cymbula species have dispersed respectively to northwest Africa, St Helena and the southern Indian Ocean. The patellids of the northeastern Atlantic form a single clade, Patella (including P. pellucida ), which may have arrived by northward dispersal of an ancestor from southern Africa, or possibly by vicariance of a widespread ancestral Tethyan distribution. The known fossil record of patellids is too fragmentary to permit choice between these alternatives.

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Simone, Luiz Ricardo L., Daniel Caracanhas Cavallari, and Rodrigo Brincalepe Salvador. "A new troglobite species of Habeastrum Simone, 2019 from Brazil, and support for classification in Diplommatinidae (Mollusca, Caenogastropoda)." Zoosystematics and Evolution 96, no. 2 (September 16, 2020): 639–47. http://dx.doi.org/10.3897/zse.96.53880.

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The genus Habeastrum Simone, 2019 was recently described based on empty shells, counting with two troglobite species. Conchological features allowed a preliminary classification in the caenogastropod family Diplommatinidae, but this family allocation was left open to future studies. Herein, we present a detailed anatomical study of newly acquired specimens, confirming the classification in Diplommatinidae. These new specimens, from Minas Gerais state, SE Brazil, belong to a new troglobite species described herein, Habeastrum strangeisp. nov. The present records extend the genus distribution ca. 1,100 km east-northeast.

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Sharma, Prashant P., Vanessa L. González, Gisele Y. Kawauchi, Sónia C. S. Andrade, Alejandra Guzmán, Timothy M. Collins, Emily A. Glover, et al. "Phylogenetic analysis of four nuclear protein-encoding genes largely corroborates the traditional classification of Bivalvia (Mollusca)." Molecular Phylogenetics and Evolution 65, no. 1 (October 2012): 64–74. http://dx.doi.org/10.1016/j.ympev.2012.05.025.

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Sulistiyaningsih, Eka, and Ucu Yanu Arbi. "ASPEK BIO-EKOLOGI DAN PEMANFAATAN KERANG MARGA ANADARA (MOLLUSCA: BIVALVIA: ARCIDAE)." OSEANA 45, no. 2 (October 27, 2020): 69–85. http://dx.doi.org/10.14203/oseana.2020.vol.45no.2.95.

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One of various shellfish in Indonesia waters that has high economic value is genus Anadara, especially as an edible marine species. Anadara is traditionally known in the trade as blood cockles. There are approximately 100 species of blood cockles in subfamily Anadarinae, the largest member of family Arcidae. Systematic of Anadarinae still does not provide certainty until now, including because there are many variations between species. Anadara, and Arcidae, in general, is one of the most abundant families of mollusc in tropical waters, and spread out in almost all of the coastal waters and found in the basis of subsystems. Its growth will be better on soft mud substrate than sandy mud substrate. Blood cockles are known as a filter feeder that feeds using gills on plankton, especially on phytoplankton. The demand for blood cockles is increasing, thus encouraging production efforts that do not only rely on harvesting from nature but through cultivation also that has been done in several places in Indonesia, such as in Sumatra and Java. This paper discussed taxonomy and classification, morphology and anatomy, habitat and distribution, reproduction and aquaculture, diet and feeding habit, and economic value of blood cockles.

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KOTZIAN, CARLA BENDER. "A New Devonian Modiolopsidae (Mollusca: Bivalvia) from the Ponta Grossa Formation, Paraná Basin, Brazil." Pesquisas em Geociências 30, no. 2 (December 31, 2003): 27. http://dx.doi.org/10.22456/1807-9806.19588.

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This paper describes the bivalve Modiolopsis (?) clarkei n. sp, coming from the Curva I outcrop, Ponta Grossa Formation. The species name was given in honor to J. M. Clarke, who first studied it. This fossil also occurs in the Durazno Group, in Uruguay, reinforcing the correlation between the Devonian Paraná Basin invertebrate fauna with others of the Malvinocaffrik Realm, as suggested by previous authors. The classification of M. (?) clarkei in a typical Ordovician genus or lineage, that can reach the Silurian and Lower Devonian periods, supports an Emsian age to the Curva I outcrop, as have been accepted.

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DAYRAT, BENOÎT. "Review of the current knowledge of the systematics of Onchidiidae (Mollusca: Gastropoda: Pulmonata) with a checklist of nominal species." Zootaxa 2068, no. 1 (April 10, 2009): 1–26. http://dx.doi.org/10.11646/zootaxa.2068.1.1.

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Because Onchidiidae (Mollusca: Gastropoda: Pulmonata) has been understudied since the last experts were active more than 70 years ago, systematics of this taxon is in a state of confusion: The nomenclatural status of most species names is unknown; the current supra-specific classification, largely based on Labbé’s work, has not been revised since the 1930s and needs to be re-evaluated through a modern, phylogenetic approach. A checklist of all 143 species names available in Onchidiidae is provided, as a first step towards a systematic revision. In addition, type material information (all existing types were examined by the author), type locality, and comments on the current taxonomic status and classification are provided for each species name. Present state of knowledge of the higher-level systematics of Onchidiidae is also briefly reviewed. Species diversity based on traditional generic taxa is presented. Finally, type localities are listed by region, worldwide, and interesting questions of biogeography are mentioned.

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Greco, Samuele, Marco Gerdol, Paolo Edomi, and Alberto Pallavicini. "Molecular Diversity of Mytilin-Like Defense Peptides in Mytilidae (Mollusca, Bivalvia)." Antibiotics 9, no. 1 (January 19, 2020): 37. http://dx.doi.org/10.3390/antibiotics9010037.

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The CS-αβ architecture is a structural scaffold shared by a high number of small, cationic, cysteine-rich defense peptides, found in nearly all the major branches of the tree of life. Although several CS-αβ peptides involved in innate immune response have been described so far in bivalve mollusks, a clear-cut definition of their molecular diversity is still lacking, leaving the evolutionary relationship among defensins, mytilins, myticins and other structurally similar antimicrobial peptides still unclear. In this study, we performed a comprehensive bioinformatic screening of the genomes and transcriptomes available for marine mussels (Mytilida), redefining the distribution of mytilin-like CS-αβ peptides, which in spite of limited primary sequence similarity maintain in all cases a well-conserved backbone, stabilized by four disulfide bonds. Variations in the size of the alpha-helix and the two antiparallel beta strand region, as well as the positioning of the cysteine residues involved in the formation of the C1–C5 disulfide bond might allow a certain degree of structural flexibility, whose functional implications remain to be investigated. The identification of mytilins in Trichomya and Perna spp. revealed that many additional CS-αβ AMPs remain to be formally described and functionally characterized in Mytilidae, and suggest that a more robust scheme should be used for the future classification of such peptides with respect with their evolutionary origin.

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Richardson, Rodney T., Johan Bengtsson-Palme, Mary M. Gardiner, and Reed M. Johnson. "A reference cytochrome c oxidase subunit I database curated for hierarchical classification of arthropod metabarcoding data." PeerJ 6 (June 26, 2018): e5126. http://dx.doi.org/10.7717/peerj.5126.

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Metabarcoding is a popular application which warrants continued methods optimization. To maximize barcoding inferences, hierarchy-based sequence classification methods are increasingly common. We present methods for the construction and curation of a database designed for hierarchical classification of a 157 bp barcoding region of the arthropod cytochrome c oxidase subunit I (COI) locus. We produced a comprehensive arthropod COI amplicon dataset including annotated arthropod COI sequences and COI sequences extracted from arthropod whole mitochondrion genomes, the latter of which provided the only source of representation for Zoraptera, Callipodida and Holothyrida. The database contains extracted sequences of the target amplicon from all major arthropod clades, including all insect orders, all arthropod classes and Onychophora, Tardigrada and Mollusca outgroups. During curation, we extracted the COI region of interest from approximately 81 percent of the input sequences, corresponding to 73 percent of the genus-level diversity found in the input data. Further, our analysis revealed a high degree of sequence redundancy within the NCBI nucleotide database, with a mean of approximately 11 sequence entries per species in the input data. The curated, low-redundancy database is included in the Metaxa2 sequence classification software (http://microbiology.se/software/metaxa2/). Using this database with the Metaxa2 classifier, we performed a cross-validation analysis to characterize the relationship between the Metaxa2 reliability score, an estimate of classification confidence, and classification error probability. We used this analysis to select a reliability score threshold which minimized error. We then estimated classification sensitivity, false discovery rate and overclassification, the propensity to classify sequences from taxa not represented in the reference database. Our work will help researchers design and evaluate classification databases and conduct metabarcoding on arthropods and alternate taxa.

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Climo, F. M. "Classification of New Zealand Arionacea (Mollusca: Pulmonata). XI. The new genusChaureopaand description of a new species ofParacharopaClimo (Charopidae)." New Zealand Journal of Zoology 12, no. 2 (April 1985): 283–96. http://dx.doi.org/10.1080/03014223.1985.10428282.

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Avila-Poveda, Omar Hernando, Brenda Paola Ramirez-Santana, Pedro Martinez-Diaz, Jorge Saul Ramirez-Perez, Nancy C. Saavedra-Sotelo, Bibiana Vargas-Trejo, Carlos Alberto Amezcua-Gomez, and Carlos Melendez-Galicia. "Complex abnormality combinations between the scleritome and the sclerites of Chiton articulatus (Mollusca: Polyplacophora): New findings for the teratological classification." Zoologischer Anzeiger 279 (March 2019): 68–81. http://dx.doi.org/10.1016/j.jcz.2019.01.003.

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Ward, D. W., and A. R. Davis. "Reproduction of the turban shell Turbo torquatus Gmelin 1791 (Mollusca : Gastropoda), in New South Wales, Australia." Marine and Freshwater Research 53, no. 1 (2002): 85. http://dx.doi.org/10.1071/mf00066.

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The Sydney turban shell Turbo torquatus is the focus of a small-scale commercial fishery in New South Wales. Effective management requires knowledge of the reproductive biology, yet this is lacking for NSW waters. The reproductive cycle was investigated at three localities on the southern New South Wales coast. Samples of T. torquatus were collected monthly at Wollongong, Ulladulla and Eden from February 1996 until August or December 1997. The reproductive cycle was investigated by three methods: monthly determination of a gonadosomatic index, estimation of oocyte size-frequency distributions and classification of female gonads into developmental stages following histological sectioning. Males and females within a population underwent synchronous gonad development and spawning. Spawning events were often protracted over a period of several months with females in various stages of gonadal development. Two spawning events occurred each year, with a spawning event in autumn–winter and another in spring–summer. These events were asynchronous among the three localities, and partial spawning appeared to be a common occurrence. Owing to variation in the timing of spawning between populations separated by a distance as small as 15 km, seasonal closures to protect spawning stocks are unlikely to be effective.

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Christian, Alan D., Sean T. McCanty, Sujata Poudel, Steve W. A. Chordas, and John L. Harris. "Inventory and Assemblage Classification of the Freshwater Mussels (Mollusca: Unionidae) of the Strawberry River, Arkansas, USA, with Implications for Conservation Planning." Diversity 13, no. 2 (February 18, 2021): 86. http://dx.doi.org/10.3390/d13020086.

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Spatial hierarchical approaches to classify freshwater systems can add to our understanding of biogeographical patterns and can be used for biodiversity conservation planning. The Strawberry River is located primarily in the Ozark Highlands Central Plateau of north central Arkansas, USA, with a small downstream portion in the Mississippi Alluvial Plain and has been designated an Extraordinary Resource Water, an Ecologically Sensitive Water Body, and a Natural Scenic Waterway. The goals of this study were to document Strawberry River, Arkansas freshwater mussels to aid in conservation planning. Our first objective was to inventory freshwater mussel species in the Strawberry River. Our second objective was to use this stream-wide dataset to classify the freshwater mussel assemblages. We used unpublished survey data of 59 sites distributed from the headwaters to the mouth to inventory species occurrence and abundance, classified mussel assemblages using non-metric multi-dimensional scaling (NMS), and conducted indicator species analysis on resulting assemblages. We observed 39 taxa across the 59 survey sites including two S1, five S2, 16 S3, 11 S4, four S5, and one state non-ranked conservation rank species. Furthermore, our assemblage NMS revealed two distinct freshwater mussel assemblages roughly organized by an upstream (Sites 1–31) to downstream (Sites 32–59) gradient. There were five upstream indicator species and 13 downstream indicator species. This study provides a case study on using existing datasets with NMS and indicator species analyses to classify mussel assemblages and adds to our understanding of freshwater mussel fauna classification at smaller spatial scales. Both NMS and indicator species outcomes can aid in conservation planning for freshwater mussels.

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O’Mahony, Micheál. "EU Regulatory Risk Management of Marine Biotoxins in the Marine Bivalve Mollusc Food-Chain." Toxins 10, no. 3 (March 10, 2018): 118. http://dx.doi.org/10.3390/toxins10030118.

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Food safety risk assessment in the European Union (EU) recognises consumer illness that arises from marine biotoxins as a risk associated with bivalve mollusc consumption. EU food regulations contain various general food safety obligations, which should contribute significantly to managing this risk. EU food regulations additionally impose various specific obligations on both Food Business Operators and Competent Authorities in order to manage the marine biotoxin food safety risk in the bivalve mollusc food-chain. These have a particular focus on the pre-harvest component of the food-chain. A central component of these specific systems is the requirement for ongoing monitoring of phytoplankton and biotoxin concentrations in water and molluscs, respectively. This monitoring explicitly brings a potential outcome of closing production areas delineated by classification to prohibit the harvest of bivalve molluscs as food from those areas when acceptable biotoxin concentrations are exceeded. This review considers the utility of these systems, at conceptual and practical levels, and explores their contribution to an effective regulatory risk management approach.

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Echeverry, Ana María, Edgardo Londoño-Cruz, and Hugo A. Benítez. "Quantifying the Geometric Shell Shape between Populations of True Limpets Lottia Mesoleuca (Mollusca: Lottidae) in Colombia." Animals 10, no. 4 (April 13, 2020): 675. http://dx.doi.org/10.3390/ani10040675.

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The increasing activity in morphological studies has provided new tools to analyses the shape quantitatively, these quantitative measurements allow the researcher to examine the variation in shape and perform analysis to examine the quantitative differences among the species shapes, where geometric morphometrics has rendered great results in the last years. This study was focused on assessing the morphometric variation between populations of Lottia mesoleuca of the family Lottidae, an abundant group of gastropods in the rocky ecosystems of Bahía Málaga and Isla Gorgona (Colombian Pacific). This family has a high morphological diversity, making the identification of some morphotypes problematic work. Geometric morphometrics methods were applied on the shell using dorsal, lateral and ventral views. Different multivariate analyses were performed to differentiate the groups of species and populations (principal component analysis, morphological distances comparisons and grouping analysis by means of the Ward method). The results indicate that individuals of the species Lottia mesoleuca have key geometric characteristics associated to the different populations (depth intertidal zones) for classification, being the geometric shape of the shell enough to determine morphotypes between the different populations studied. Aspects associated with the combination of ecological variables with morphometric ones are necessary to be able to visualize with a higher resolution the structural complexity of populations and their adaptation processes. Furthermore, it is obvious that there is a strong need to conduct more explorations of environmental and ecological processes that provide some insight on why the morphological characteristics are so variable in the same species.

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Sigwart, Julia D., Enrico Schwabe, Hiroshi Saito, Sarah Samadi, and Gonzalo Giribet. "Evolution in the deep sea: a combined analysis of the earliest diverging living chitons (Mollusca : Polyplacophora : Lepidopleurida)." Invertebrate Systematics 24, no. 6 (2010): 560. http://dx.doi.org/10.1071/is10028.

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Lepidopleurida is the earliest diverged group of living polyplacophoran molluscs. They are found predominantly in the deep sea, including sunken wood, cold seeps, other abyssal habitats, and a few species are found in shallow water. The group is morphologically identified by anatomical features of their gills, sensory aesthetes, and gametes. Their shell features closely resemble the oldest fossils that can be identified as modern polyplacophorans. We present the first molecular phylogenetic study of this group, and also the first combined phylogenetic analysis for any chiton, including three gene regions and 69 morphological characters. The results show that Lepidopleurida is unambiguously monophyletic, and the nine genera fall into five distinct clades, which partly support the current view of polyplacophoran taxonomy. The genus Hanleyella Sirenko, 1973 is included in the family Protochitonidae, and Ferreiraellidae constitutes another distinct clade. The large cosmopolitan genus Leptochiton Gray, 1847 is not monophyletic; Leptochiton and Leptochitonidae sensu stricto are restricted to North Atlantic and Mediterranean taxa. Leptochitonidae s. str. is sister to Protochitonidae. The results also suggest two separate clades independently inhabiting sunken wood substrates in the south-west Pacific. Antarctic and other chemosynthetic-dwelling species may be derived from wood-living species. Substantial taxonomic revision remains to be done to resolve lepidopleuran classification, but the phylogeny presented here is a dramatic step forward in clarifying the relationships within this interesting group.

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Barón, Pedro J., and María E. Ré. "Morphometry of the northern Patagonian sympatric populations of Loligo sanpaulensis and Loligo gahi." Journal of the Marine Biological Association of the United Kingdom 82, no. 2 (April 2002): 269–78. http://dx.doi.org/10.1017/s0025315402005453.

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Loligo gahi and Loligo sanpaulensis (Mollusca: Cephalopoda), two squid species presently under exploitation in the south-west Atlantic, are sympatric in coastal waters of northern Patagonia. In the present study, the morphometry of both species' northern Patagonian populations was analysed and compared. Relationships between the morphometric variables and mantle length, the standard measure of size for squids, are allometric in most cases. Weight and fin length show different rates of growth relative to mantle length in males and females of both species. Fin length, fin width and mantle length are the best morphometric variables to discriminate the mantle/fin complexes. Free rachis length, gladius length and gladius width are the most useful to separate both species' pens. The best discrimination of the tentacles is provided by the diameter of the central and marginal suckers and the number of teeth on the three largest sucker rings. Discriminant functions are provided to allow the classification of individuals from both species and the identification of pens and tentacle clubs found in predators digestive contents.

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Glaubrecht, Matthias, Lothar Maitas, and Luitfried v. Salvini-Plawen. "Aplacophoran Mollusca in the Natural History Museum Berlin. An annotated catalogue of Thiele's type specimens, with a brief review of “Aplacophora” classification." Mitteilungen aus dem Museum für Naturkunde in Berlin - Zoologische Reihe 81, no. 2 (September 2005): 145–66. http://dx.doi.org/10.1002/mmnz.200510009.

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Glaubrecht, Matthias, Lothar Maitas, and Luitfried V. Salvini-Plawen. "Aplacophoran Mollusca in the Natural History Museum Berlin. An annotated catalogue of Thiele's type specimens, with a brief review of “Aplacophora” classification." Mitteilungen aus dem Museum für Naturkunde in Berlin. Zoologische Reihe 81, no. 2 (2005): 145–66. http://dx.doi.org/10.1002/mmnz.4850810204.

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Guevara-Fletcher, Carlos E., Jaime R. Cantera Kintz, Luz M. Mejía-Ladino, and Fabián A. Cortés. "Benthic Macrofauna Associated with Submerged Bottoms of a Tectonic Estuary in Tropical Eastern Pacific." Journal of Marine Biology 2011 (2011): 1–13. http://dx.doi.org/10.1155/2011/193759.

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The composition and distribution of the main associations of submerged macrobenthos ofBahía Málaga(Colombian pacific coast), were studied in relation to the distribution of hard and soft substrates and some abiotic factors. Eight localities were sampled during six months: three in the external border of the estuary and five in the inner part. In total, 728 organisms were registered, belonging to 207 species, 132 genera, 86 families, and 14 orders of six invertebrate groups (Porifera, Cnidaria, Polychaeta, Mollusca, Crustacea, and Echinodermata). The submerged bottoms presented soft and hard substrates, with rocks and thick sand in five sites, soft bottoms with fine sand in one, and soft bottoms with slime and clay in two. The temperature and salinity values were higher in the external localities, while dissolved oxygen and pH were higher in the internal localities. The localities with hard substrates presented the highest richness of species while the soft substrates, were characterized by a paucity of species and individuals. The similarity classification analyses showed two groups: one characterized by having 61 species in common and high richness with 113 exclusive species. The other group with low diversity and richness values, 37 species in common and 23 exclusive species.

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De Kock, K. N. "Distribution and habitats of Ceratophallus natalensis (Mollusca: Planorbidae) in South Africa." Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie 26, no. 2 (September 21, 2007): 109–19. http://dx.doi.org/10.4102/satnt.v26i2.128.

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Species of the genus Ceratophallus are known only from some islands in the western Indian Ocean and Africa, where they occur in Eritrea and the area extending southwards and westwards into the Western Cape of South Africa. The most recent classification recognises nine species of this genus of which only two, namely Ceratophallus natalensis (Krauss) and Ceratophallus gibbonsi (Nelson) occur in South Africa. Although partially sympatric, C. gibbonsi is largely associated with a tropical climate and perennial water-bodies while C. natalensis is fairly common in cooler areas and are often found in ephemeral rain pools. This article focuses on the geographical distribution and habitats of C. natalensis, the most widespread species of the genus, as reflected by the data on record in the National Freshwater Snail Collection (NFSC). Details pertaining to the habitats of 1 797 samples of C. natalensis as recorded at the time of collection were extracted from the database of the NFSC. In view of the finding of Brown1 that C. natalensis and C. gibbonsi are partly sympatric, but that the latter is associated with fully tropical climatic areas, samples of Ceratophallus collected in loci ( 1 / 16 th square degrees) that fall within the altitude interval ranging from 0-500 m, were selected for closer investigation. A number of 153 samples from 64 loci falling within this altitude interval was subsequently identified as C. natalensis. The number of loci in which the 1 797 collection sites were located, was distributed in intervals of mean annual air temperature and rainfall, as well as intervals of mean altitude, to illustrate the frequency of occurrence within specific intervals. A temperature index was calculated for all mollusc species in the database from their frequencies of occurrence within selected temperature intervals and the results were used to rank them in order of their association with low to high climatic temperatures. Chi-square values were calculated to evaluate the significance of the difference between the frequency of occurrence in, on, or at the different options for each variable. Additionally, an effect size value was calculated to determine the significance of the effect of all the different variables discussed in this paper on the geographical distribution of C. natalensis in South Africa. A multivariate analysis in the form of a decision tree was also constructed. This is a statistical model that enables the selection and ranking of those variables that can maximally discriminate between the frequency of occurrence of a given species under specific conditions as compared to all other mollusc species in the database.The 1 797 samples of C. natalensis of which the collection sites could be located on a 1:250 000 topo-cadastral map series of South Africa were spread over 334 loci. This species was recovered from all types of water-bodies represented in the database but the largest percentage was reported from dams (31.2%), streams (22.2%) and rivers (15.7%). The majority of samples came from habitats with perennial (60.0%), standing (62.9%), clear (63.8%) and fresh (76.7%) water, while 42.1% of the samples were recovered from habitats with a muddy substratum. More than 95% of the samples were reported from sites that fell within the temperature interval ranging from 16-20°C and the majority of samples (64.8%) came from sites falling within the rainfall interval ranging from 601–900 mm. More than 50% of the samples came from sites falling within the altitude interval ranging from 1 001–1 500 m and this differed significantly from the frequency of occurrence within all the alternative altitude intervals. The temperature index calculated for C. natalensis ranked it in the eighth position for all species in the database due to its association with low climatological temperatures. However, the effect size values calculated for this index for 18 of the other 53 species in the database did not differ significantly from the value calculated for C. natalensis. A moderate to large effect size value was calculated for temperature and altitude suggesting that these two variables played an important role in the geographical distribution of C. natalensis, a finding also substantiated by the results of the decision tree analysis. Harrison8 divided the riverine and stream invertebrates of southern Africa into two main groups – a so-called old element with Gondwanaland affinities with relatives in other southern continents and a Pan-Ethiopian (Sub-Saharan) element. Also included in this last element are some species associated with temperate climate and sometimes with mountains, that obviously related to the African fauna. According to this author this group includes the following four sub- groups: (1) widespread species found in tropical and temperate climates, (2) warm stenothermal, tropical species, (3) Highveld-temperate climate species, (4) montane, cold stenothermal species and (5) temporary mountain stream species. According to Brown9 C. natalensis could be placed in the more or less eurythermal sub-group (1). This is supported by the geographical distribution of the collection sites of the samples of C. natalensis depicted in figure 1. Presently this species is the only member of the subfamily Planorbinae reported from Lesotho and it is currently on record from nine loci in that country in our database. It is therefore not surprising that the temperature index calculated for this species ranked it under the eight species in the database most closely associated with cooler climatic conditions. It is reported in literature that this species can utilise a wide variety of habitats including ephemeral water-bodies like marshes, slow-flowing streams, natural depressions and ditches only briefly filled with water. This is supported by the results of the present investigation which indicated the presence of this species in all types of water-body on record in the database and that 26% of the samples came from temporary habitats. It is not known whether C. natalensis can serve as intermediate host for any human helminth parasite. However, Loker et al. 12 reported the shedding of 11 different trematode cercariae from naturally infected snails in Tanzania and Frandsen and Christensen13 mention at least 10 different cercariae which could be shed from species of Ceratophallus under natural conditions. To our knowledge no efforts have been made to establish the possible role of C. natalensis as intermediate host of economically important helminth parasites in South Africa. In view of its relatively wide distribution in this country and the reports that it can act as intermediate host of a variety of helminth parasites elsewhere in Africa, it is recommended that its role as potential intermediate host in South Africa should be investigated.

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Inkhavilay, Khamla, Chirasak Sutcharit, Ueangfa Bantaowong, Ratmanee Chanabun, Warut Siriwut, Ruttapon Srisonchai, Arthit Pholyotha, Parin Jirapatrasilp, and Somsak Panha. "Annotated checklist of the terrestrial molluscs from Laos (Mollusca, Gastropoda)." ZooKeys 834 (April 3, 2019): 1–166. http://dx.doi.org/10.3897/zookeys.834.28800.

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The land area of Laos is composed of a large variety of undisturbed habitats, such as high mountainous areas, huge limestone karsts and the lower Mekong Basin. Therefore, Laos is expected to have a high species diversity, especially for the land snails. However, with respect to research on malacology, Laos is probably the least well-researched area for land snail diversity in Indochina (including Laos) over the past few centuries. The handful of species lists have never been systematically revised from the colonial period to the present, so these classifications are outdated. Herein we present the first comprehensive annotated checklist with an up-to-date systematic framework of the land snail fauna in Laos based on both field investigations and literature surveys. This annotated checklist is collectively composed of 231 nominal species (62 ‘prosobranch’ and 169 heterobranches), of which 221 nominal species are illustrated. The type specimens of 143 species from several museum collections and/or 144 species of newly collected specimens are illustrated. There are 58 species recorded as new to the malacofauna of the country, and two new replacement names are proposed as Hemiplectalanxangnica Inkhavilay and Panha, nomen novum (Ariophantidae) and Chloritiskhammouanensis Inkhavilay and Panha, nomen novum (Camaenidae). Four recently described species of the genus Amphidromus from Laos, “thakhekensis”, “richgoldbergi”, “attapeuensis” and “phuonglinhae” are synonymized with previously described species. In addition, thirteen nominal species are listed as uncertain records that may or may not occur in Laos. This annotated checklist may inspire malacologists to carry on systematic research in this region.

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BREURE, ABRAHAM S. H., and JONATHAN D. ABLETT. "An ironic twist of fate: replacement name for Stenogyra gracilenta Morelet, 1885, not Achatina gracilenta Morelet, 1867 (Mollusca, Gastropoda, Achatinidae)." Zootaxa 4418, no. 3 (May 8, 2018): 299. http://dx.doi.org/10.11646/zootaxa.4418.3.8.

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During work on a monograph of Morelet’s contributions to malacology (Breure, Audibert & Ablett, forthcoming) we found that two of his newly introduced taxa currently have to be considered as homonyms belonging to the genus Subulina H. Beck, 1837 (classified within the family Achatinidae according to Fontanilla et al. (2017: 385)). The older taxon is Achatina gracilenta which was described by Morelet (1867: 79, pl. 7 fig. 2) from [Angola] “Golungo-Alto, au bord du Rio Quiapose, près de Sange; les environs de Lopollo (district de Huilla)”. According to Naggs (1990a: 31; also pers. comm. 10 October 2017) this species has to be classified as Subulina gracilenta (Morelet, 1867). The type material of this species is present in the Natural History Museum, London (NHMUK 1893.2.4.263–265). The younger taxon was described by Morelet (1885: 25, pl. 2 fig. 8) as Stenogyra gracilenta from [Gabon] “environs de Mayumba”. Pilsbry (1906: 82) already recognised this as Subulina gracilenta (Morelet, 1885); Naggs (pers. comm. 10 October 2017) confirmed this classification and concluded that this taxon is a junior secondary homonym of Achatina gracilenta Morelet, 1867. Type material for Stenogyra gracilenta Morelet, 1885 has not been located. We here propose Subulina bruggenorum nom. nov. as a replacement name for Stenogyra gracilenta Morelet, 1885 (not Achatina gracilenta Morelet, 1867).

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Wedel, Joachim. "Pleistocene molluscs from research boreholes in the Heidelberg Basin." E&G Quaternary Science Journal 57, no. 3/4 (April 1, 2009): 382–402. http://dx.doi.org/10.3285/eg.57.3-4.6.

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Abstract. Cores cut in the research boreholes at Viernheim and Parkinsel P34 and P35 in Ludwigshafen were analysed to investigate their fossil content, and particularly the remains of molluscs. The selected material was suitable for reconstructing the palaeoclimatic conditions and simplifies the chronostratigraphic classification of individual beds. Two mollusc species and one rodent species from the Lower Pleistocene (Lower Biharium) were identified in the northern Upper Rhine Graben for the first time (in the Viernheim borehole). The fossils from the Lower Pleistocene sections of the Viernheim borehole are clearly related to the Uhlenberg fauna from Bavarian Swabia dated as Upper Villanium/Tegelen.

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DESMOND RAMIREZ, M., DANIEL I. SPEISER, M. SABRINA PANKEY, and TODD H. OAKLEY. "Understanding the dermal light sense in the context of integrative photoreceptor cell biology." Visual Neuroscience 28, no. 4 (July 2011): 265–79. http://dx.doi.org/10.1017/s0952523811000150.

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AbstractWhile the concept of a dermal light sense has existed for over a century, little progress has been made in our understanding of the mechanisms underlying dispersed photoreception and the evolutionary histories of dispersed photoreceptor cells. These cells historically have been difficult to locate and positively identify, but modern molecular techniques, integrated with existing behavioral, morphological, and physiological data, will make cell identification easier and allow us to address questions of mechanism and evolution. With this in mind, we propose a new classification scheme for all photoreceptor cell types based on two axes, cell distribution (aggregated vs. dispersed) and position within neural networks (first order vs. high order). All photoreceptor cells fall within one of four quadrants created by these axes: aggregated/high order, dispersed/high order, aggregated/first order, or dispersed/first order. This new method of organization will help researchers make objective comparisons between different photoreceptor cell types. Using integrative data from four major phyla (Mollusca, Cnidaria, Echinodermata, and Arthropoda), we also provide evidence for three hypotheses for dispersed photoreceptor cell function and evolution. First, aside from echinoderms, we find that animals often use dispersed photoreceptor cells for tasks that do not require spatial vision. Second, although there are both echinoderm and arthropod exceptions, we find that dispersed photoreceptor cells generally lack morphological specializations that either enhance light gathering or aid in the collection of directional information about light. Third, we find that dispersed photoreceptor cells have evolved a number of times in Metazoa and that most dispersed photoreceptor cells have likely evolved through the co-option of existing phototransduction cascades. Our new classification scheme, combined with modern investigative techniques, will help us address these hypotheses in great detail and generate new hypothesis regarding the function and evolution of dispersed photoreceptor cells.

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Fauziyah, Fauziyah, Wike Ayu Eka Putri Wike Ayu Eka Putri, Desi Arianti Desi Arianti, Fitri Agustriani Fitri Agustriani, Rozirwan Rozirwan, Ellis Nurjuliasti Ningsih Ellis Nurjuliasti Ningsih, and Anna Ida Sunaryo Purwiyanto Anna Ida Sunaryo Purwiyanto. "Discarded Species in Artisanal Fisheries South Sumatra, Indonesia: Case Study on Crab Gill Nets." Sains Malaysiana 51, no. 9 (September 30, 2022): 2745–56. http://dx.doi.org/10.17576/jsm-2022-5109-01.

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This study identified the discard species generated by the crab gillnet for targeting the blue swimming crab Portunus pelagicus (Linnaeus 1758) in the Banyuasin estuarine of South Sumatra, Indonesia. The fishing gear yielded the discarded catch about 12% (25.68 kg) of the total catch in weight (212.68 kg). For the discarded catch, 703 individuals represented 18 species from 3 phyla (Arthropoda, Chordata, and Mollusca). The crustaceans Charybdis helleri (Milne-Edwards 1867), Clibanarius spp., Matuta planipes(Fabricius 1798), and Libinia dubia(Milne Edwards 1834) were the majority components of these discards accounted for 90% of the total discards. Results of ecological classification rare, i.e., Chiloscyllium indicum(Gmelin 1789), and occasional, i.e., Chiloscyllium punctatum(Müller & Henle 1838), and Maculabatis macrura(Bleeker 1852) included in the International Union for Conservation of Nature (IUCN) red list as Vulnerable (C. indicum), Near Threatened (C. punctatum), and Endangered (M. macrura) category. Based on the IUCN status, two species of crustaceans i.e., Carcinoscorpius rotundicauda (Latreille 1802) and Tachypleus gigas (Müller 1785) listed as ‘Data Deficient’. Discarded on crab gillnet fishing in Banyuasin waters is a challenge for species that need to be conserved (shark, ray, and horseshoe crabs). Species with IUCN red list status ranging from Data Deficient to Endangered were found dead, except for horseshoe crabs. Mitigation options offered include captive breeding of horseshoe crabs, the release of protected species when caught, and fishing gear modification. These findings can help design suitable mitigations for discarding crab gill nets.

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Labibah, Novatul, Herowati Herowati, Jefri Nur Hidayat, and Habibi Habibi. "EKSPLORASI AKTIVITAS KEHIDUPAN SEHARI-HARI ANAK NELAYAN DI DESA LOBUK UNTUK MENDUKUNG PEMBELAJARAN IPA KONTEKSTUAL." EDUSAINS 12, no. 2 (December 30, 2020): 266–75. http://dx.doi.org/10.15408/es.v12i2.14938.

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EXPLORATION OF FISHERMAN CHILDREN'S DAILY LIFE ACTIVITIES AT LOBUK VILLAGE TO SUPPORT CONTEXTUAL SCIENCE LEARNINGAbstractThe daily activities of fishermen's children can be used as a material context in applying contextual science learning, as emphasized by K13. In fact, learning science in coastal schools is not yet contextual to the daily activities of fishermen's children. This study aims to provide a description of the daily activities of fishermen's children in Lobuk Village, and a description of the relationship between these activities and science learning materials for SMP/MTs. This type of research is a descriptive qualitative case study method. The primary data sources were fishermen children aged SMP/MTs and their parents. Data collection techniques in the form of interviews, observation, and documentation. The results showed that fishermen's children's morning activities were helping with homework, preparing for school, then leaving for school. The daytime activity is helping the mother/aunt work in the drying process of the fish (a gherri jhuko'). The afternoon activity is looking for shells (arang-karang) during low tide, some of the shells are sold to earn pocket money or for parents, and some are used as salad. Nighttime activities are reciting/tarawih, tadarus, watching TV, then sleeping. The daily activities of fishermen children in their routine of helping to work a gherri jhuko’ and arang-karang in Lobuk Village are related to science learning materials for SMP/MTs, namely the classification of shells in Mollusca type invertebrates; the application of solid substance pressure to the knife for nyetak, mowang bunto ', and a gherri jhuko'. AbstrakAktivitas sehari-hari anak nelayan bisa digunakan sebagai konteks materi dalam menerapkan pembelajaran IPA kontekstual, sebagaimana penekanan K13. Faktanya, pembelajaran IPA di sekolah pesisir belum kontekstual terhadap aktivitas sehari-hari anak nelayan. Penelitian ini bertujuan untuk memberikan deskripsi aktivitas sehari-hari anak nelayan di Desa Lobuk, dan deskripsi keterkaitan aktivitas tersebut dengan materi pembelajaran IPA SMP/MTs. Jenis penelitian ini adalah deskriptif kualitatif dengan metode studi kasus. Sumber data primer dari anak-anak nelayan usia SMP/MTs beserta orang tua. Teknik pengumpulan data berupa wawancara, observasi, dan dokumentasi. Hasil penelitian menunjukkan aktivitas pagi hari anak nelayan adalah membantu pekerjaan rumah, menyiapkan diri ke sekolah, lalu berangkat sekolah. Aktivitas siang hari adalah membantu ibu/bibinya bekerja dalam proses pengeringan ikan (a gherri jhuko’). Aktivitas sore hari adalah mencari kerang (arang-karang) saat air laut surut, sebagian kerang dijual untuk menghasilkan uang jajan atau untuk orang tua, dan sebagian lagi dirujak. Aktivitas malam hari adalah mengaji/tarawih, tadarus, nonton TV, lalu tidur. Aktivitas sehari-hari anak nelayan dalam rutinitas membantu bekerja a gherri jhuko’ dan arang-karang di Desa Lobuk berkaitan dengan materi pembelajaran IPA SMP/MTs, yaitu pengklasifikasian kerang dalam avertebrata jenis Mollusca; penerapan tekanan zat padat pada pisau untuk nyetak, mowang bunto’, dan a gherri jhuko’.

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Fusco, Giovanna, Aniello Anastasio, David H. Kingsley, Maria Grazia Amoroso, Tiziana Pepe, Pina M. Fratamico, Barbara Cioffi, Rachele Rossi, Giuseppina La Rosa, and Federica Boccia. "Detection of Hepatitis A Virus and Other Enteric Viruses in Shellfish Collected in the Gulf of Naples, Italy." International Journal of Environmental Research and Public Health 16, no. 14 (July 19, 2019): 2588. http://dx.doi.org/10.3390/ijerph16142588.

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To assess the quality of shellfish harvest areas, bivalve mollusk samples from three coastal areas of the Campania region in Southwest Italy were evaluated for viruses over a three-year period (2015–2017). Screening of 289 samples from shellfish farms and other locations by qPCR and RT-qPCR identified hepatitis A virus (HAV; 8.9%), norovirus GI (NoVGI; 10.8%) and GII (NoVGII; 39.7%), rotavirus (RV; 9.0%), astrovirus (AsV; 20.8%), sapovirus (SaV; 18.8%), aichivirus-1 (AiV-1; 5.6%), and adenovirus (AdV, 5.6%). Hepatitis E virus (HEV) was never detected. Sequence analysis identified HAV as genotype IA and AdV as type 41. This study demonstrates the presence of different enteric viruses within bivalve mollusks, highlighting the limitations of the current EU classification system for shellfish growing waters.

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Jirapatrasilp, Parin, Chirasak Sutcharit, and Somsak Panha. "Annotated checklist of the operculated land snails from Thailand (Mollusca, Gastropoda, Caenogastropoda): the family Pupinidae, with descriptions of several new species and subspecies, and notes on classification of Pupina Vignard, 1829 and Pupinella Gray, 1850 from mainland Southeast Asia." ZooKeys 1119 (August 25, 2022): 1–115. http://dx.doi.org/10.3897/zookeys.1119.85400.

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Thailand is located at the crossroads of several biogeographical regions, and boasts a high level of biodiversity, especially among the malacofauna. The most recent checklist of land snail species in Thailand was compiled more than twenty years ago, and so this checklist needs revision and the addition of newly discovered taxa. This study updates the taxonomy and species list of the operculated land snail family Pupinidae from Thailand. This snail family is diverse and abundant, and can be found in various natural habitats in Southeast Asia. Although the taxonomy of some Southeast Asian pupinid genera has been reviewed, studies of Pupina Vignard, 1829, which contains the highest number of species, and a lesser-known genus Pupinella Gray, 1850 are still lacking. Herein we present an annotated checklist with an up-to-date systematic framework of the Pupinidae in Thailand based on both field investigations and literature surveys, and include the taxonomic treatment of all Pupina and Pupinella species from mainland Southeast Asia. This annotated checklist contains 30 nominal species and two subspecies from seven genera currently known to occur in Thailand. We describe two species of Pseudopomatias (P. doiangkhangensis Jirapatrasilp, sp. nov. and P. pallgergelyi Jirapatrasilp, sp. nov.), five species and one subspecies of Pupina (P. bensoni Jirapatrasilp, sp. nov., P. bilabiata Jirapatrasilp, sp. nov., P. godwinausteni Jirapatrasilp, sp. nov., P. latisulci Jirapatrasilp, sp. nov., P. stoliczkai Jirapatrasilp, sp. nov., and P. dorri isanensis Jirapatrasilp, ssp. nov.) as new to science. New records of Coptocheilus sumatranus, Pupinella mansuyi, and Rhaphaulus tonkinensis are also reported from Thailand. The mainland Southeast Asian Pupina species are classified into three species groups (Pupina artata group, Pupina arula group, and Pupina aureola group) based on the distinction of shell teeth and canals, and operculum. Three species formerly in Pupina from Vietnam are allocated to Pupinella (P. illustriscomb. nov., P. sonlaensiscomb. nov., and P. thaitranbaiicomb. nov.) due to the presence of a funnel-like anterior canal.

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Sadamoto, Hisayo, Hironobu Takahashi, Suguru Kobayashi, Hirooki Kondoh, and Hiroshi Tokumaru. "Identification and classification of innexin gene transcripts in the central nervous system of the terrestrial slug Limax valentianus." PLOS ONE 16, no. 4 (April 15, 2021): e0244902. http://dx.doi.org/10.1371/journal.pone.0244902.

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Intercellular gap junction channels and single-membrane channels have been reported to regulate electrical synapse and the brain function. Innexin is known as a gap junction-related protein in invertebrates and is involved in the formation of intercellular gap junction channels and single-cell membrane channels. Multiple isoforms of innexin protein in each species enable the precise regulation of channel function. In molluscan species, sequence information of innexins is still limited and the sequences of multiple innexin isoforms have not been classified. This study examined the innexin transcripts expressed in the central nervous system of the terrestrial slugLimax valentianusand identified 16 transcripts of 12 innexin isoforms, including the splicing variants. We performed phylogenetic analysis and classified the isoforms with other molluscan innexin sequences. Next, the phosphorylation, N-glycosylation, and S-nitrosylation sites were predicted to characterize the innexin isoforms. Further, we identified 16 circular RNA sequences of nine innexin isoforms in the central nervous system ofLimax. The identification and classification of molluscan innexin isoforms provided novel insights for understanding the regulatory mechanism of innexin in this phylum.

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Ibrahim, Putri Sapira. "KARAKTERISTIK DAN ASPEK BIOLOGI Scaphopoda (MOLUSKA)." OSEANA 44, no. 2 (December 30, 2019): 1–9. http://dx.doi.org/10.14203/oseana.2017.vol.42no.2.24.

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CHARACTERISTICS AND BIOLOGICAL ASPECTS OF Scaphopoda (MOLLUSCS). Scaphopoda are bilaterally symmetrical marine molluscs, commonly known as the "tusk shells" because their shells are conical. There are approximately 900 species of Scaphopoda, found in soft silty marine sediments, which they burrow in search of food. Scaphopoda feeds on microorganisms, their diet dominated by foraminiferans. Hermaphroditic scaphopoda has been reported but rare. The biodiversity of Scaphopoda had been underestimated because the taxonomic and biological aspects of scaphopoda have not been well studied. Classification, morphology, reproduction, behavior, habitat, and distribution of Scaphopoda are discussed in this paper.

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CAMPOS, ERNESTO. "On the pea crabs found in the chiton Tonicia chilensis (Frembly, 1827) (Mollusca, Polyplacophora: Chitonidae) identified as “Orthotheres sp.” by Melzer & Schwabe (2008), and its reassignment to Calyptraeotheres Campos, 1990 (Crustacea: Pinnotheridae)." Zootaxa 4434, no. 2 (June 15, 2018): 385. http://dx.doi.org/10.11646/zootaxa.4434.2.11.

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Crabs of the family Pinnotheridae have been considered a phylogenetically heterogeneous group and taxonomically problematic (Palacios-Theil 2009, 2016; Tsang et al. 2018). The lack of knowledge of sexual dimorphism and morphological variation throughout the life history for many species have complicated its taxonomy and has resulted in errors in its classification (Campos 1989, 1993, 2016). Consequently, if the taxonomy of these symbiotic crabs had been based on juveniles and undeveloped character states, the problems get even more serious (Campos 1989, 1993). Melzer & Schwabe (2008) studied three juvenile crabs living in the chiton Tonicia chilensis (Frembly, 1827) (Polyplacophora: Chitonidae) collected in Muelle Dichato, Chile, and they identified them as the putative invasive stage of a species of Orthotheres Sakai, 1969. The crabs are of the typical juvenile pinnotherid form with a masculine habitus, including a suborbicular carapace, large eyes and a slender pleon (= abdomen) with the telson well defined (Ocampo et al. 2017). Unpublished observations on juveniles and adults of several species of pinnotherid crabs by the author, for example, Juxtafabia muliniarum (Rathbun, 1918), Dissodactylus lockingtoni Glassell, 1935, D. xantusi Glassell, 1936, Calyptraeotheres granti (Glassell, 1933), Austinotheres angelicus (Lockington, 1877) and Tumidotheres margarita (Smith, 1870) have revealed that the third maxilliped exhibit little morphological variation through the post-larval stages of development (from juvenile to adult). This appendage, including the partial or total fusion of the ischium and merus (Fig. 1A–G; Fig 2A, C–G), has been considered a valuable feature for distinguishing genera in the family Pinnotheridae (Bürger 1895; Rathbun 1918; Manning 1993; Ahyong & Ng 2007; Campos 2009). According to Melzer & Schwabe (2008) the ischium and merus of the third maxilliped are completely fused, the carpus is larger than the propodus and the small dactylus is subterminally inserted on the propodus (Fig 1C), and as such the juveniles studied are possibly members of the genus Orthotheres Sakai, 1969. A detailed re-examination of the third maxilliped, chela of pereiopod 1 (cheliped) and pleon, however, has shown otherwise. Campos (1989) discussed the taxonomy of Orthotheres and treated all the species he recognised as belonging to this genus; characterising its members by its diagnostic third maxilliped palp structure. Ng & Ho (2014) rediagnosed the genus based on the type species, O. turboe Sakai, 1969, from Japan, and restricted it for three Indo-West Pacific species; commenting that the American species as well as some Indo-West Pacific taxa will need to referred to other genera when a full revision is done. This revision is now in progress by the author, PKL Ng and ST Ahyong. Until the revision is complete, the genus is treated here in the broader sense of Campos (1989) and Geiger & Martin (1999).

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Wang, Xue Feng, Zhi Ming Liu, and Wen Jian Wu. "Progress of Molluscan Nacre Proteins Research." Advanced Materials Research 998-999 (July 2014): 283–86. http://dx.doi.org/10.4028/www.scientific.net/amr.998-999.283.

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Nacre composing the inner layer of mollusk shell is a typical product of biomineralization. While main components of the organics in nacre are proteins, which mediate its distinctive lamellate structure. Although kinds of nacre proteins have been reported, the whole process of nacre formation is still unclear—especially on molecular level. In this paper, homology, structure, classification and mineralization characters of nacre proteins are elaborated and summarized.

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Lowther, James A., Nicole E. Gustar, Andrew L. Powell, Rachel E. Hartnell, and David N. Lees. "Two-Year Systematic Study To Assess Norovirus Contamination in Oysters from Commercial Harvesting Areas in the United Kingdom." Applied and Environmental Microbiology 78, no. 16 (June 8, 2012): 5812–17. http://dx.doi.org/10.1128/aem.01046-12.

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ABSTRACTThe contamination of bivalve shellfish with norovirus from human fecal sources is recognized as an important human health risk. Standardized quantitative methods for the detection of norovirus in molluscan shellfish are now available, and viral standards are being considered in the European Union and internationally. This 2-year systematic study aimed to investigate the impact of the application of these methods to the monitoring of norovirus contamination in oyster production areas in the United Kingdom. Twenty-four monthly samples of oysters from 39 United Kingdom production areas, chosen to represent a range of potential contamination risk, were tested for norovirus genogroups I and II by using a quantitative real-time reverse transcription (RT)-PCR method. Norovirus was detected in 76.2% (643/844) of samples, with all sites returning at least one positive result. Both prevalences (presence or absence) and norovirus levels varied markedly between sites. However, overall, a marked winter seasonality of contamination by both prevalence and quantity was observed. Correlations were found between norovirus contamination and potential risk indicators, including harvesting area classifications,Escherichia coliscores, and environmental temperatures. A predictive risk score for norovirus contamination was developed by using a combination of these factors. In summary, this study, the largest of its type undertaken to date, provides a systematic analysis of norovirus contamination in commercial oyster production areas in the United Kingdom. The data should assist risk managers to develop control strategies to reduce the risk of human illness resulting from norovirus contamination of bivalve molluscs.

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STEINER, GERHARD. "PHYLOGENY AND CLASSIFICATION OF SCAPHOPODA." Journal of Molluscan Studies 58, no. 4 (1992): 385–400. http://dx.doi.org/10.1093/mollus/58.4.385.

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Journal articles on the topic 'Mollusca, classification'

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