Meeting Abstract
One thing I’ve learned growing up on Cape Cod is that like tourists in the summer, Doryteuthis pealeii will also come and go. Since spending more time on the water in Nantucket and Vineyard Sound this year, I have begun to notice complex seasonal patterns of local squid in size, sexual maturation and lifespan but year-round dynamics remain poorly understood and possible underlying genetic structure is contentious. The species occurs from New Foundland to the Gulf of Venezuela and is fished commercially from Southern Georges Bank to Cape Hatteras, including a long-standing fisheries here in Woods Hole and the Cape Cod region. During summer the Long Fin Inshore squid inhabit the waters close to shore but then go offshore in winter. Beginning in early May there is a distinct size class of very large and sexually mature D. pealeii but then by late July mature females are half the size, and potentially have half the lifespan. To characterize genetic structure within the local squid we sampled 30 animals of different size classes once a week for 16 weeks and once a month thereafter. Weight, length, gonad maturity, and sex identification were assessed as well as two arm tips per animal were collected and frozen for sequencing. With over 500 samples, we were able to extract DNA and generate two data sets commonly used in population genetics, microsatellites, expanding on previous work by others, and mitochondrial control region sequencing, which offers potentially greater signal for resolving any genetic structure over time.
