Spatiotemporal genetic structure in a protected marine fish, the California Grunion (Leuresthes tenuis), and relatedness in the genus Leuresthes.

The genus Leuresthes displays reproductive behavior unique among marine fish in which mature adults synchronously emerge completely out of the water to spawn on beach land. A limited number of sandy beaches, which are suitable for these spawning events, are present in discontinuous locations along the geographic range of the species, potentially limiting gene flow and the degree of genetic homogeneity between intraspecific populations. Here, we tested for molecular genetic differentiation between 363 individuals, representing 3 populations of California grunion, Leuresthes tenuis, by employing 2 mitochondrial and 4 nuclear DNA markers.

Three divergent mitochondrial genomes from California populations of the copepod Tigriopus californicus.

Previous work on the harpacticoid copepod Tigriopus californicus has focused on the extensive population differentiation in three mtDNA protein coding genes (COXI, COXII, Cytb). In order to get a more complete understanding of mtDNA evolution in this species, we sequenced three complete mitochondrial genomes (one from each of three California populations) and compared them to two published mtDNA genomes from an Asian congener, Tigriopus japonicus. Several features of the mtDNA genome appear to be conserved within the genus: 1) the unique order of the protein coding genes, rRNA genes and most of the tRNA genes, 2) the genome is compact, varying between 14.