Sharks International, 2014

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† 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

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

Published by pauljclerkin

Paul J. Clerkin is a researcher with a master’s degree from Moss Landing Marine Laboratories currently working on his PhD at the Virginia Institute of Marine Science. Clerkin specializes in rare and deep-sea chondrichthyans and focuses on new species descriptions, taxonomy, life histories, genetics, and tagging of poorly understood shark species. His outside-the-box approach combines working with local fishers and high-tech innovative research techniques such as remotely operated vehicles (ROVs), specialized deep-sea cameras, and satellite archival tags. His research has granted him a variety of opportunities including leading workshops for the United Nations, serving as a shark expert for a Food and Agriculture Organization’s research cruise, and producing several shark documentaries. He has conducted research projects aboard ships in the Indian, Atlantic, and Pacific oceans. Clerkin has discovered over a dozen new species of sharks and has gotten in the water to tag some of the rarest sharks on the planet including the ultra-rare Megamouth Shark. Paul Clerkin is currently describing new species that he has discovered, preparing a workshop for the Republic of Mauritius regarding their National Plan of Action for sharks, and organizing an international research program for sharks. His research interests include: shark taxonomy, robotics, artificial intelligence, eDNA, biologgers, and marine conservation policy. Find him @ deepblueresearchfoundation.org https://pauljclerkin.com/ Twitter: @PaulJClerkin Instagram: paul_j_clerkin Facebook: @PaulJClerkin

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