Discipline: Biological Sciences
Room: Exhibit Hall A
Brittany Baker - Oakland University
It has been observed that the rate of growth of offshore, Atlantic deep-sea scallops is lower than that of the inshore, shallow water scallops and it has been hypothesized that this may be due to a difference in food availability. Previous microscopy-based studies have found that in offshore scallops, the pelagic diatom species Eucampia zoodiacus, Ditylum brightwelii, and Coscinodiscus spp. were the principal components of the diet in the early fall, which coincides with the period of greatest water column mixing and the bloom period for these species. Additionally, another diatom genus, Thalassiosira, was found to supply a substantial portion of the energy consumed by inshore P. magellanicus during the spring bloom. I hypothesized that the following diatoms groups may be important components of the environment and food resources due to their presence in past visual surveys: Eucampia zoodiacus, Ditylum brightwelii, Coscinodiscus spp., Thalassiosira, Bacillariophyta (onshore), Chaetoceros, Fragilariopsis, and Corethron. The results of this study established a molecular based approach to identify diatoms present in the gut contents of samples of Atlantic deep-sea scallops. Results are compared to previous findings based on microscopy. The development of these methods will be important because the mechanics of sea scallop feeding (mortar and pestle type grinding by a crystalline style) makes visual identification of diatoms difficult. In my research, I extracted diatom DNA from scallop digestive glands, amplified fragments of the COI and rbcL genes, cloned and finally sequenced. The control I used for sequencing was the control which came with the kit to gauge how successful my cloning was and that all the reagents were reacting properly. I identified 35 diatom sequences belonging to several orders within the gut contents of sea scallops using BLAST searches and phylogenetic trees. I would recommend using the marker rbcL as a barcode for identifying diatoms in gut contents. The results of this study provide additional insight on a scalable method to assess the diet of sea scallops, which impacts its growth, and thus contributes to our ability to sustainably manage it as a resource. Verifying my primers work for specific cultured diatom species would further prove my primers work for diatoms. References: Malviya, S., Scalco, E., Audic, S., Vincent, F., Veluchamy, A., Poulain, J., Wincker, P., Iudicone, D., Vargas, C., Bittner, L., Zingone, A., Bowler, C. 2016. Insights into global diatom distribution and diversity in the world?s ocean. P. Natl. A. Sci. Plus 113(11), E1516-E1525. Shumway, S.E., Selvin, R., Schick, D.F. 1987. Food resources related to habitat in the scallop Placopecten magellanicus (Gmelin, 1791): a qualitative study. J. Shellfish Res. 6(2), 89-95. Shumway, S.E., Parsons, G.J. 2016. Scallops: biology, ecology, aquaculture, and fisheries. Dev. Aquacult. Fish. Sci. 40(3), 1196 pp.
Funder Acknowledgement(s): Program funding for the VIMS Research Experience for Undergraduates was made available through a grant awarded from the National Science Foundation (grant # NSF OCE 1659656) to Drs. Linda Schaffner and Rochelle Seitz.
Faculty Advisor: Jan McDowell, firstname.lastname@example.org
Role: I was a part of the entire research process (it was my project and I am the sole author of the paper), however I did have the aid of my mentors (posing a research question and how to go about conducting the research, in the laboratory, and editing my paper) and graduate students in my laboratory.