Phylogenetic analysis of the Lancinae (Gastropoda, Lymnaeidae) with a description of the U.S. federally endangered Banbury Springs lanx.

We examined the patelliform snails of the subfamily Lancinae, endemic to northwestern North America, to test whether morphological variation correlated with genetic and anatomical differences. Molecular analyses using , 16S, calmodulin intron, and 28S rDNA partial sequences and anatomical data supported recognition of four species in three genera. The relationships of lancines within Lymnaeidae are not yet well-resolved.

The evolution of reproductive isolation in a simultaneous hermaphrodite, the freshwater snail Physa.

Background: The cosmopolitan freshwater snail Physa acuta has recently found widespread use as a model organism for the study of mating systems and reproductive allocation. Mitochondrial DNA phylogenies suggest that Physa carolinae, recently described from the American southeast, is a sister species of P. acuta.

Pulmonate phylogeny based on 28S rRNA gene sequences: a framework for discussing habitat transitions and character transformation.

Pulmonate snails occupy a wide range of marine, estuarine, freshwater and terrestrial environments. Non-terrestrial forms are supposed to be basal in pulmonate evolution but the group's phylogeny is not well resolved either morphologically or on the basis of available DNA sequence data. The lack of a robust phylogeny makes it difficult to understand character polarization and habitat transformation in pulmonates.

Identification of 'extinct' freshwater mussel species using DNA barcoding.

Freshwater mollusks are highly imperiled, with 70% of the North American species extinct, endangered, or at risk of extinction. Impoundments and other human impacts on the Coosa River of Alabama, Georgia and Tennessee of the southeastern USA alone are believed to have caused 50 mollusk species extinctions, but uncertainty over boundaries among several putatively closely related species makes this number preliminary. Our examination of freshwater mussels collected during an extensive survey of the upper-drainage basin, DNA barcoding and molecular phylogenetic analyses confirm the rediscovery of four morphospecies in the genus Pleurobema (Unionidae) previously thought to be extinct from the upper Coosa basin.

Molecular phylogeny and biogeography of spring-associated hydrobiid snails of the Great Artesian Basin, Australia.

The Great Artesian Basin (GAB) of Australia underlies some of the driest parts of South Australia and Queensland and feeds numerous freshwater springs. Prominent and endangered components of the GAB spring community are snails of the family Hydrobiidae. This paper examines the evolutionary relationships of the entire hydrobiid fauna associated with the GAB, and includes appropriate non-GAB species to place the GAB fauna in a broader phylogenetic context.

Complete mtDNA sequence of the North American freshwater mussel, Lampsilis ornata (Unionidae): an examination of the evolution and phylogenetic utility of mitochondrial genome organization in Bivalvia (Mollusca).

Molluscs in general, and bivalves in particular, exhibit an extraordinary degree of mitochondrial gene order variation when compared with other metazoans. Two factors inhibiting our understanding the evolution of gene rearrangement in bivalves are inadequate taxonomic sampling and failure to examine gene order in a phylogenetic framework. Here, we report the first complete nucleotide sequence (16,060 bp) of the mitochondrial (mt) genome of a North American freshwater bivalve, Lampsilis ornata (Mollusca: Paleoheterodonta: Unionidae).

Molecular systematics of the North American freshwater bivalve genus Quadrula (Unionidae: Ambleminae) based on mitochondrial ND1 sequences.

A molecular phylogeny of the bivalve genus Quadrula (Unionidae) was constructed based on nucleotide sequences of the mitochondrial ND1 gene. Phylogenetic analysis of 66 specimens representing 17 of the 20 currently recognized taxa within Quadrula, three closely allied species, and 16 outgroup taxa reveals a non-monophyletic Quadrula due to the placement of Tritogonia verrucosa, 'Fusconaia' succissa, and 'Quincuncina' infucata. We suggest that the taxonomic description of the genus Quadrula be expanded to include these species.

Phylogeny, taxonomy, genetics and global heritage ranks of an imperilled, freshwater snail genus Lithasia (Pleuroceridae).

Numerous aquatic species are threatened with extinction from habitat elimination or modification. One particularly imperilled group is the freshwater gastropod family Pleuroceridae. Pleurocerids reach their greatest diversity in the southeastern United States, and many species are currently considered extinct, endangered or threatened.

Molecular phylogeny of a circum-global, diverse gastropod superfamily (Cerithioidea: Mollusca: Caenogastropoda): pushing the deepest phylogenetic limits of mitochondrial LSU rDNA sequences.

The Cerithioidea is a very diverse group of gastropods with ca. 14 extant families and more than 200 genera occupying, and often dominating, marine, estuarine, and freshwater habitats. While the composition of Cerithioidea is now better understood due to recent anatomical and ultrastructural studies, the phylogenetic relationships among families remain chaotic.

Phylogeographic analysis of the threatened and endangered superconglutinate-producing mussels of the genus Lampsilis (Bivalvia: Unionidae).

Several species of freshwater unionid mussels in the genus Lampsilis exhibit a remarkable reproductive strategy. Female mussels of these species enclose their larvae in a minnow-like lure, called a 'superconglutinate', to attract piscivorous fishes. When a fish attempts to ingest the superconglutinate the lure ruptures and the larvae are released to parasitize the fish.

Phylogenetic analysis of molluscan mitochondrial LSU rDNA sequences and secondary structures.

Mollusks are an extraordinarily diverse group of animals with an estimated 200,000 species, second only to the phylum Arthropoda. We conducted a comparative analysis of complete mitochondrial ribosomal large subunit sequences (LSU) of a chiton, two bivalves, six gastropods, and a cephalopod. In addition, we determined secondary structure models for each of them.

Phylogenetic utility of the tyrosine kinase gene X-src for assessing relationships among representative cichlid fishes.

The nuclear gene X-src is a member of the tyrosine-kinase class of proto-oncogenes whose normal product is localized within the cytoplasm of the cell. The X-src gene has been used in only a few phylogenetic studies, each focusing on systematics of killifishes (Cyprinodontiformes). The present study is an attempt to examine the phylogenetic utility of X-src for uncovering relationships of representative cichlid fishes, especially the cichlids of Middle America.

Molecular systematics of Middle American cichlid fishes and the evolution of trophic-types in 'Cichlasoma (Amphilophus)' and 'C. (Thorichthys)'.

The majority of Middle American cichlids are placed in the informal assemblage 'Cichlasoma.' The group is divided into eight sections which appear to be based primarily on trophic morphology. Although several members of 'Cichlasoma' have been used in ecomorphological, behavioral, and biogeographic studies, no phylogenetic hypotheses for the group exist.

A molecular phylogeny of Mobile River drainage basin pleurocerid snails (Caenogastropoda: Cerithioidea).

Sequences from the mitochondrial 16S rRNA gene were obtained to construct a molecular phylogeny for Mobile River drainage basin pleurocerid snails. Data from 876 aligned positions generated a single most-parsimonious tree for each of three analytical approaches: (1) equal weighting, (2) transversions weighted 2 x transitions; and (3) transversions weighted 4 x transitions. Identical topologies for the resulting trees depict the genera Elimia and Pleurocera as monophyletic sister taxa.

Molecular systematics and evolution of reproductive traits of North American freshwater unionacean mussels (Mollusca: Bivalvia) as inferred from 16S rRNA gene sequences.

North American freshwater unionacean bivalves are a diverse group of nearly 300 species. Unionaceans exhibit an array of conchological, anatomical, life history, and reproductive characteristics that have figured prominently in proposed classification schemes. Recently, two very different classifications of North American unionaceans have been proposed.

A molecular phylogeny of the gopher tortoises, with comments on familial relationships within the Testudinoidea.

Sequences from the mitochondrial cytochrome b gene were obtained to examine molecular phylogenetic relationships among the North American gopher tortoises. Data from 352 aligned positions generated a single most-parsimonious tree for each of three analytical approaches: (1) equal weighting, all substitutions; (2) equal weighting, third position changes limited to transversions; and (3) transversions weighted 10 times transitions. Identical topologies for the resulting trees depict the gopher tortoises as a monophyletic group comprising two well-defined clades.

The evolution of copulatory organs, internal fertilization, placentae and viviparity in killifishes (Cyprinodontiformes) inferred from a DNA phylogeny of the tyrosine kinase gene X-src.

Cyprinodontiforms are a diverse group of approximately 900 pantropical and temperate fishes, mostly found in freshwater. Whereas the vast majority of fishes lay eggs (i.e.

COMPARATIVE POPULATION GENETIC STRUCTURE OF A PARASITE (FASCIOLOIDES MAGNA) AND ITS DEFINITIVE HOST.

The population genetic structure of the American liver fluke, Fascioloides magna, and its definitive host the white-tailed deer, Odocoileus virginianus, was examined in South Carolina. Flukes were significantly more common in deer from river-swamp habitat than upland areas and prevalence increased with host age. The distribution of flukes among deer occurred as a negative binomial with the mean dispersion parameter, k, equal to 0.

Parasitic and phoretic arthropods of the elephant-eared and the Santa Cruz kangaroo rats.

The parasitic and phoretic arthropods of the elephant-eared kangaroo rat (Dipodomys elephantinus) and Santa Cruz kangaroo rat (D. venustus) are reported; most of these represent new host records. Thirteen of 14 (93%) of D.