Meeting Abstract

P1-7  Sunday, Jan. 4 15:30  Distribution of Acartia spp. in central San Francisco Bay and San Pablo Bay is not related to temperature and salinity variation. FRANKLIN, D.T.*; HOLMES, A.E.; CRAIG, C; COHEN, C.S.; Georgia Southern University; San Francisco State University; San Francisco State University; San Francisco State University

Copepods are the most abundant metazoans in the world, and due to their roles as primary consumers and critical food sources for higher trophic levels, they are ecologically important. Still, like many marine species, taxonomic identities and distributional patterns are not well known, leaving large gaps in our understanding of aquatic food webs and the potential for ongoing climate change to affect critical food web linkages. Cryptic species of Acartia in Chesapeake Bay show distributions related to salinity. In San Francisco Bay (SFB), Acartia species are not well defined ecologically or taxonomically. In this study, Acartia collections (n=14) were made at 6 locations spanning temperature and salinity ranges of 15.8-18.6 C and 19 to 34 ppt to test for distribution patterns related to environmental variation. Sixty samples were barcoded with ~ 500 nucleotides of the 18S rDNA locus and compared with available sequence in Genbank. Three distinct supported clades were found in SFB; two were inferred to represent A. tonsa and A. hudsonica. Environmental and geographic sampling information was mapped against the clade data to test for distribution patterns related to temperature, salinity, or other spatial variation. North American west coast Acartia show a different pattern from their east coast congeners with broad distributions for 3 clades in SFB. The results contribute to the first molecular comparison of Acartiaspp. distribution in SFB, and suggest broad and overlapping use of varying habitats by distinct clades.