† Paul J Clerkin1*, David A Ebert 1, and Gavin J P Naylor2
REPRODUCTIVE BIOLOGY AND MATURITY OF DEEP-SEA SHARKSIN THE SOUTHERN INDIAN OCEAN
1-Pacific Shark Research Center, Moss Landing Marine Laboratories, 8272 Moss Landing Road,Moss Landing, CA 95039, USA 2-Hollings Marine Laboratory, College of Charleston, 331 Ft. Johnson Road, Charleston, SC29412, USA, Oral Presentation, 2014 Sharks International, Durban, South, Africa, 2014 **Not present
Abstract: Examination of Chondrichthyans from a survey of Southern Indian Ocean seamounts aimed to: 1) survey species in this region, 2) construct a DNA-based phylogenetic framework as part of the Assembling the Tree of Life project, and 3) assess life history characteristics of elasmobranchs. Reproductive and maturity data including sex, length, maturity stage, oviducal gland development, egg widths and numbers were recorded and analyzed from 2,700 Chondrichthyans collected during a 2-month trawling operation southeast of Madagascar. Length of 50% maturity was calculated and reproductive organ measurements compared against total length. Sex ratios, size dimorphism, and total lengths of the smallest mature and largest immature were examined. Approximately 400 specimens of the genera Centrophorus, Deania, Centroscymnus, Centroselachus, Proscymnodon, Zameus, Etmopterus, Dalatias, Apristurus, Bythaelurus, Pseudotriakis, Hydrolagus, and Chimaera were collected from 500 m–1,500 m depths. Over 700 tissue samples for DNA studies and 225 vertebrae and spines for age/growth studies were collected and qualitative diet data were recorded from sharks including poorly known species, e.g., Proscymnodon plunketi and Pseudotriakis microdon, and several undescribed species of Etmopterus, Apristurus, Parmaturus, Hydrolagus, and Chimaera. Project specimens were deposited at the American Museum of Natural History, the California Academy of Sciences, and the Smithsonian Institution. The expedition was an international collaboration between Moss Landing Marine Laboratories, College of Charleston, Southern Indian Ocean Deepsea Fishers Association, Sealord Corporation, and Mauritius Ministry of Fisheries, and was funded, in part, by NSF grant: DEB-01132229.
Keywords: deep-sea, Indian Ocean, reproduction, maturity, biodiversity, seamounts