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Showing 1 to 20 of 64 for “"Bivalvia"”.
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Population genetics of the genus Transennella (Bivalvia)
<p>Genetic variation at twelve loci which code for enzymes and non-enzymatic protein has been studied by means of starch gel electrophoresis in two apparent species of the pelecypod genus Transennella, Variable allozymes include esterase, leucine aminopeptidase, malate dehydrogenase, phosphoglucose …
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Byssus Production in Freshwater Mussels (Bivalvia: Unionoidea)
Freshwater mussels (Order Unionoida) are a widespread and ecologically significant group of bivalve mollusks that are particularly diverse in North American rivers. Mussels are patchily distributed, but can be very abundant in suitable habitat and dense multispecies aggregations known as "mussel …
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Crayfish Predation on Juvenile Freshwater Mussels (Bivalvia: Unionidae)
North American native freshwater mussels are among the most endangered faunal groups in the world. Juvenile mussels are very small and potentially vulnerable to a wide variety of predators, including crayfish. This study examines predation by a native crayfish, Orconectes neglectus on juvenile …
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Kriauklių proteomika: Unionida (Bivalvia, Mollusca) kriauklių baltymų analizė rūšių identifikavimui /
Mollusks are one of the most widely used animal species. In prehistory people used mollusks as a source of food, decorated clothes, used shells to make jewelry, work tools and decorate pottery. However, it is difficult for scientists to accurately taxonomically determine which species were used in …
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UTTERBACKIA IMBECILLIS (BIVALVIA: UNIONIDAE) AS A BIOLOGICAL INDICATOR OF COPPER POLLUTION
The freshwater mussel, <italic>Utterbackia imbecillis</italic>, is an ideal biological indicator of aquatic ecosystems because of its widespread geographic distribution, abundance, and sedentary, filter-feeding lifestyle. The present study evaluated the physiological responses of <italic>U. …
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Evaluation of Diet, Gametogenesis, and Hermaphroditism in Freshwater Mussels (Bivalvia: Unionidae)
To determine the effects of different algal diets on freshwater mussels, tissues of Elliptio complanata were sampled for physiological, somatic, and gametogenic condition from August 1999 to May 2000. Treatments included mussels fed Scenedesmus quadricauda (S), Neochloris oleoabundans (N), a no …
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Reproductive ecology and population dynamics of two sympatric species of Macoma (Bivalvia)
Populations of the sympatric intertidal bivalves, Macoma secta and M. nasuta are compared as to reproductive ecology and population dynamics. Histological examination of seasonal gonadal changes indicate that both species undergo dormancy in the winter months and rapid gamete proliferation in the …
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The Effect of Flow on Burrowing in Juvenile Freshwater Mussels (Bivalvia, Unionidae)
<p>Burrowing is a significant factor in the survival of freshwater mussels; it helps to prevent dislodgement from the sediment, and it reduces the risk of predation. In this study the burial time and orientation of juvenile mussels were tested in response to flow and substrate in a recirculating …
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Life History of the Spectaclecase, Cumberlandia Monodonta Say, 1829 (Bivalvia, Unionoidea, Margaritiferidae)
<p>Cumberlandia monodonta is a distinctive species of freshwater mussel that was formerly widespread in the Mississippi River Basin, but has suffered drastic decline. Reproductive biology and demography of Cumberlandia were investigated in the Gasconade and Meramec Rivers, Missouri, which appear to …
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Keanekaragaman bivalvia dan asosiasinya dengan hutan mangrove di Pantai Talang Kabupaten Pamekasan
… marina dan Pemphis adicula. Sedangkan jenis bivalvia yang ditemukan terdiri dari 5 spesies, yaitu Anadara granusa, Anadara antiquata Meretrix spp, Crassostrea spp, Adrana patagonica. Dan dari data ini menunjukkan bahwa tingkat keanekaragaman hutan mangrove dan jenis bivalvia termasuk rendah, …
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Contribuição ao conhecimento de Macoma (Austromacoma) constricta (Bruguière, 1792) (Bivalvia, Heterodonta, Tellinidae)
… order to place the refered subfamily among the Bivalvia. Characterization, as well as geological and geographic distribution, is presented for the genera and subgenera, along with general considerations and illustrations of the shells of the species occuring on the Brazilian coast. ln relation …
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Resolving the evolutionary history of multiple groups of freshwater mussels (Bivalvia : Unionidae).
Freshwater mussels are a group of aquatic invertebrates comprised of approximately one thousand species worldwide, and the greatest diversity of freshwater mussels lies within North America with at least three hundred species. The high level of biodiversity in this group is strongly shaped by a …
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Sensitivity of early life stages of freshwater mussels (Bivalvia: Unionidae) to copper
Four life stages of freshwater mussels were tested for their sensitivity to copper and a metal-containing effluent. This permitted an assessment of the variability in sensitivity among the life stages in order to identify those stages most threatened in the wild from copper exposure. Glochidia, …
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Approaches for assessing toxicity of selected contaminants to freshwater mussels (Bivalvia: Unionidae)
Laboratory bioassays results suggest that early life stages of freshwater mussels are sensitivity to toxicants. However, toxicological databases for unionids are rather limited because standard test methods are yet developed, and no published studies report endpoints for chronic test that are > 9 …
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Bivalvia and paleoecology of the Fox Hills Formation (Upper Cretaceous) of North Dakota
<p> The bivalve fauna of the Fox Hills Formation, Maestrichtian, of North Dakota was studied in an attempt to modernize the nomenclature of known bivalves, describe new forms, interpret the relationships of members of the formation, and establish the paleoecological setting in which the Fox Hills …
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Distribution and life history of the endangered James Spinymussel, pieurobema collina (bivalvia: unionidae)
Distribution of the James spinymussel (Pleurobema collina) and aspects of its life history were studied from June 1987 to October 1989. Field and laboratory observations were used to determine gravidity and glochidial release periods, fish host requirements, age class structure, growth …
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Assessing Freshwater Mussels (Bivalvia: Unionidae) in South Dakota and Identifying Drivers of Assemblage Variation
<p>Native freshwater mussels (Family: Unionidae) are among the most threatened groups of freshwater fauna on Earth. Approximately 35 species have gone extinct since the 1900s and 72% of remaining species are considered endangered, threatened, or species of special concern. Unionid research can …
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Distribuição de Teredinidae Rafinisque, 1815 (Mollusca: Bivalvia) ao longo da costa sudeste do Brasil
The distribution of teredinid wood-boring molluscs along part of the southeast coast of Brazil was studied. The infestation levels were correlated to ecological factors such as wood supply, and the presence of fouling or competitor organisms. The hypothesis tested was: there is an infestation …
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Time-Averaging and Morphology: Variability in Modern Populations and Fossil Assemblages of Mercenaria (Bivalvia)
… living populations of Mercenaria campechiensis (Bivalvia) and two fossil assemblages of M. campechiensis and M. permagna. One fossil sample was collected as a series of superposed units that could be analyzed individually or in aggregate. The x,y coordinates of 13 landmarks and pseudolandmarks …
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