Contrasting Patterns of Genetic Diversity and Divergence Between Landlocked and Migratory Populations of Fish , Evaluated Through Mitochondrial DNA Sequencing and Nuclear DNA Microsatellites.

species are interesting biogeographic models due to their distribution and different types of life cycles, with migratory and landlocked populations. To obtain a better understanding of the genetic consequences of the Quaternary glacial cycles in , in this work we compared landlocked and migratory populations collected in areas that were differentially affected by ice advances and retreats. We included nine populations of , four collected from lakes (landlocked) and five from their associated estuaries/rivers (migratory) in three estuary-lake systems across southern Chile.

Gonadal cycle, reproductive indices and detection of parasitism in the clam Ameghinomya antiqua in natural beds of importance for fisheries.

The clam Ameghynomia antiqua is a highly important resource for fisheries due to its high catches volume. It is the bivalve mollusc with the highest fisheries landings from natural beds on the Pacific coast of southern South America; however, studies of the reproductive conditions of this species are scarce and date back many years. The object of the present work was to evaluate the reproductive characteristics of the species, analysing its gametogenic and gonadal cycle, and reproductive indices, in fishery locations that present the natural beds with the highest fisheries catches, as well as parasite loads in the species.

Presence of two mitochondrial genomes in the mytilid Perumytilus purpuratus: Phylogenetic evidence for doubly uniparental inheritance.

This study presents evidence, using sequences of ribosomal 16S and COI mtDNA, for the presence of two mitochondrial genomes in Perumytilus purpuratus. This may be considered evidence of doubly uniparental mtDNA inheritance. The presence of the two types of mitochondrial genomes differentiates females from males.

Genetic considerations for mollusk production in aquaculture: current state of knowledge.

In 2012, world mollusk production in aquaculture reached a volume of 15,171,000 tons, representing 23% of total aquaculture production and positioning mollusks as the second most important category of aquaculture products (fishes are the first). Clams and oysters are the mollusk species with the highest production levels, followed in descending order by mussels, scallops, and abalones. In view of the increasing importance attached to genetic information on aquaculture, which can help with good maintenance and thus the sustainability of production, the present work offers a review of the state of knowledge on genetic and genomic information about mollusks produced in aquaculture.