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Showing 1 to 20 of 53 for “"Unionidae"”.
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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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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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Development of an Algal Diet for Rearing Juvenile Freshwater Mussels (Unionidae)
Feeding selectivity by the rainbow mussel (Villosa iris) was examined for three age groups; 2-3 days old, 50-53 days old, and 3-6 years old. The mussels were fed an algal diet consisting of Scenedesmus quadricauda (22.3 - 44.5 μm), Nannochloropsis oculata (2.8 – 8.1 μm), and Selenastrum …
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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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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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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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Reproductive Biology of the Flat Floater Mussel, Anodonta Suborbiculata, Say, 1831 (Mollusca: Unionidae)
The flat floater mussel, Anodonta suborbiculata , is a large, distinctive freshwater bivalve that formerly occurred in shallow lentic habitats throughout the Mississippi River Drainage. The flat floater is presently rare due to habitat loss. Several aspects of the reproductive biology of this …
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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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A Quantitative Survey of the Freshwater Mussel (Unionidae) Fauna in Honeoye Creek, New York
Contemporary baseline data such as species presence, distribution, abundance, size-class structure, species-habitat relationships, and host species distributions are needed for monitoring the status and health of freshwater mussel communities in Honeoye Creek and other watersheds in New York State …
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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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The Effect of Dieoffs of Asian Clams (Corbicula fluminea) on Native Freshwater Mussels (Unionidae)
There is a great deal of concern about the declining freshwater mussel fauna of North America. Although deteriorating water quality and habitat degradation may account for much of the decline, it has been suggested that the exotic Asian clam, Corbicula fluminea, may be having an effect on native …
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Survival and condition of riverine freshwater mussels (Unionidae) confined in cages suspended in ponds
The survival of 1,729 freshwater mussels (15 species) was monitored in ponds at study sites in Critz, Blacksburg and Marion, Virginia. Mussels were held within plastic and metal screen cages fastened to PVC float collars. Survival in the pond at Critz was 73% overall, with significant differences …
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A Descriptive Survey of Freshwater Unionidae Bivalves in Five Creeks Located in West Central Georgia
… The survey is intended to determine whether Unionidae populations remain extant in this portion of the Chattahoochee River drainage, and to estimate the abundance and distribution of species encountered. Accessibility sampling was employed; sites selected to be surveyed were usually located …
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Genetic And Morphological Assessment Of Pigtoe Mussels (unionidae: Pleurobemini: Fusconaia/pleurobema Spp.) in Ozark Drainages
<p>North America is home to nearly 300 species of native freshwater mussels. Many species within this group are in need of conservation efforts and for these efforts to be effective, species delimitations must be as accurate as possible. Intraspecific variation and interspecific convergence are …
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Genetics, demography and modeling of freshwater mussel (Bivalvia: Unionidae) populations in the Clinch River, U.S.A.
Genetic variation was examined in two endangered mussel species, Epioblasma brevidens and E. capsaeformis, and a common species Lampsilis fasciola, in the Clinch River, TN, by screening mitochondrial DNA (mtDNA) sequences and nuclear DNA microsatellites. These species use fish hosts with varying …
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The influence of hydrological variability on the spatial distribution and orientation of freshwater mussels (Bivalvia: Unionidae).
… and relative abundance of mussels (Bivalvia: Unionidae) was determined for three event (i.e., hydrologically flashy) and three stable (i.e., hydrologically stable) drainage basins. Multivariate analyses revealed that distinct mussel communities exist based on the hydrological variability of …
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Acute Toxicity of Ammonia and Copper to Mussel (Bivalvia: Unionidae) Glochidia Inside and Outside of Conglutinates
Regulations regarding the allowable limits of water pollution are often based on the levels of those pollutants that are toxic to the most sensitive freshwater organisms. Freshwater mussels (Unionoida) are unusually sensitive to certain pollutants and therefore have potential to drive water quality …
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