January 1, 2019.
Leptasterias spp. is a species complex of six-rayed intertidal sea stars found along the northeast Pacific coast. A developmental mode of brooding their young, rather than broadcasting for planktonic development, limits dispersal away from the natal area, and may also result in local adaptation of populations. Local adaptation may lead to morphological and behavioral differences among populations. Previous studies on behavior in Leptasterias spp. have shown that activity levels may vary by population and region. Across three regions from California to Washington, differences were only observed between central California and more northern regions while northern California, Oregon, and Washington were similar to each other in activity level. Here, we tested whether regions showing similarity in behavioral activity are also genetically similar in clade composition. Mitochondrial DNA barcoding was used to determine species and clade overlap among the two similar regions. DNA was extracted from arm tip and tube feet tissue samples from stars found in intertidal sites from three different regions; Washington, northern California, and central California. Mitochondrial CO1 sequence was obtained from the DNA via PCR and Sanger sequencing at the Estuary and Ocean Science Center, SFSU Genetics Lab to determine whether different species of Leptasterias spp. have different activity levels. Three species level clades of Leptasterias spp. are found in these regions., L. hexactis, L. aequalis, and L. pusilla. Regional differences in clade and species composition were observed between Washington stars and stars from California however, no difference in clade or species composition was observed between northern and central California. Previous behavior studies identified no significant difference in activity level between Washington and northern California stars, yet a significant difference between central California stars in comparison to Washington and northern California. These findings and the corresponding genetic analysis suggest that clade and species composition is not a sole determinant of activity levels in Leptasterias spp.
San Francisco State University (SFSU)
The 2018 STEM Teacher and Researcher Program and this project have been made possible through support from Chevron (www.chevron.com), the National Marine Sanctuary Foundation (www.marinesanctuary.org), the National Science Foundation through the Robert Noyce Program under Grant #1836335 and 1340110, the California State University Office of the Chancellor, and California Polytechnic State University in partnership with San Francisco State University. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the funders.