The in vivo response of adult northern quahogs, Mercenaria mercenaria, to Aureococcus anophagefferens (brown tide) at the level of the gill was determined using video-endoscopy. Feeding activity, particle-approach velocities, and ventral-groove-transport velocities were documented after the quahogs were exposed to Isochryis galbana (baseline observations) supplemented with either toxic or nonto...

The marine clam, Tivela mactroides, from Caño Sagua beach, Venezuela, was spawned and reared under laboratory conditions to monitor its early development. Spawning was spontaneous but in some cases it had to be induced by the additon of eggs and sperm. After fertilization, the embryonic development occurred at 5 hr approximately. Trochophore larvae were observed between eight and ten hours late...

Part of the genus Lioconcha Mörch, 1853 is reviewed. Species strongly resembling Lioconcha castrensis (Linnaeus, 1758) are discussed and two new species are described: Lioconcha arabaya n. sp. from the Northwest Indian Ocean and Lioconcha rumphii n. sp. from Thailand and Sumatra. These three species, together with Lioconcha macaulayi Lamprell & Healy, 2002, share many morphological similarities...

The selection of a DNA extraction method is a critical step when subsequent analysis depends on the DNA quality and quantity. Unlike mammals, for which several capable DNA extraction methods have been developed, for molluscs the availability of optimized genomic DNA extraction protocols is clearly insufficient. Several aspects such as animal physiology, the type (e.g., adductor muscle or gills)...

This paper describes the fine structure of oocysts of Nematopsis sp. (Apicomplexa, Porosporidae) found in the abductor muscles of seawater clams, Meretrix meretrix (Linnaeus, 1758) (Veneridae), collected near the city of Dammam (6 degrees 17'0"N, 50 degrees 12'0"E) in the Arabian Gulf off the coast of Saudi Arabia. Oocysts of an ellipsoidal shape were found among myofibrils of the abductor musc...

Mollusks are some of the most important, abundant and diverse organisms inhabiting not only aquatic ecosystems, but also terrestrial environments. Recently, they have been used for bioremediation of aquaculture effluents; nevertheless, for that purpose it is necessary to analyze the capacity of a particular species. In this context, an experimental investigation was developed to evaluate the pe...

Doubly uniparental inheritance (DUI) provides an intriguing system for addressing aspects of molecular evolution and intermolecular recombination of mitochondrial DNA. For this reason, a large sequence analysis has been performed on Tapes philippinarum (Bivalvia, Veneridae), which has mitochondrial DNA heteroplasmy that is consistent with a DUI. The sequences of a 9.2-kb region (containing 29 g...

The population dynamics of an intertidal population of Megapitaria squalida was studied from September 2002 to February 2003 in Bahia Magdalena, Mexico. To obtain information about the artisanal and recreational fishery of M. squalida, local fishermen at different parts of the bay were interviewed. Clam densities were determined at one unexploited and two exploited sites along perpendicular tra...

Doubly uniparental inheritance (DUI) of mitochondrial DNA, different from maternal inheritance, is known to occur in five bivalve families (Mytilidae, Veneridae, Unionidae, Margaritiferidae, Hyriidae). DUI involves two types of mitochondrial DNA: F type, inherited from the mother and M type, inherited from the father. Females have only F type mtDNA, males have both types, M type being located i...