Title: Taxonomy and systematics of Arctic Thoridae (Decapoda: Caridea)
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Principal Investigator Mary Wicksten, Luis Hurtado, Texas A&M University, College Station, USA |
Project goals
Molecular analysis of alcohol-preserved shrimp specimens from the Arctic for taxonomic revision and estimate of time of divergence between populations.
Results
We used the DNAEasy kit and PCR to amplify four mitochondrial and three nuclear genes from the following Arctic species: Eualus belcheri, Lebbeus groenlandicus, Spirontocaris arcuata and S. ochotensis. We ran preliminary phylogenetic analyses on our data set. Each of the supposed genera (Heptacarpus, Eualus, Spirontocaris and Lebbeus) form a well supported clade, distinct from species of Hippolyte and Lysmata. These data strongly support distinction of the Thoridae as a family distinct from the Hippolytidae in the old sense. Of particular interest is the genetic distance of Spirontocaris sica from the two Arctic species of Spirontocaris. Morphological and ecological evidence has suggested that S. sica and S. holmesi, found from Washington to Baja California, should be placed in a separate genus. So far, the Arctic species seem to be distinct from those taken farther south, suggesting an earlier divergence time between them than within clades from farther to the south.
