Ontogenetic vertebral growth patterns in the basking shark Cetorhinus maximus
Lisa J. Natanson1,*, Sabine P. Wintner2, Friederike Johansson3, Andrew Piercy4, Patrick Campbell5, Alessandro De Maddalena6, Simon J. B. Gulak7, Brett Human8, Franco Cigala Fulgosi9, David A. Ebert10, Farid Hemida11, Frederik H. Mollen12, Stefano Vanni13, George H. Burgess4, Leonard J. V. Compagno14, Andrew Wedderburn-Maxwell15
1National Marine Fisheries Service (NMFS), Northeast Fisheries Science Center, NOAA, 28 Tarzwell Drive, Narragansett, Rhode Island 02882-1199, USA
2Natal Sharks Board, Private Bag 2, 4320 Umhlanga Rocks, and Biomedical Resource Unit, University of KwaZulu-Natal, PO Box X54001, Durban 4000, South Africa
3Vertebrate Section, Göteborg Natural History Museum, Box 7283, 402 35 Göteborg, Sweden
4Florida Program for Shark Research, Florida Museum of Natural History, University of Florida, PO Box 117800, Gainesville, Florida 32611, USA
5Department of Zoology, Natural History Museum, Cromwell Road, London SW7 5BD, UK
6Banca Dati Italiana Squalo Bianco, Via L. Ariosto 4, 20145 Milan, Italy
7Pelagic Observer Program, South East Fisheries Science Centre, National Marine Fisheries Service, NOAA,
75 Virginia Beach Drive, Miami 33149, Florida, USA
8Marine Science and Fisheries Centre (Biodiversity Project), PO Box 467, PC 100 Muscat, Sultanate of Oman
9Dipartimento Scienze della Terra, Università di Parma, Parco Area delle Scienze 152/A, 43100 Parma, Italy
10Pacific Shark Research Center, Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, California 95039, USA
11Laboratoire Ecologie et Environnement (Projet Halieutique), Faculté des Sciences Biologiques (FSB), Université des Sciences et Techniques Houari Boumedienne (USTHB), BP 32, El Alia, 16111 Bab Ezzouar, Alger, Algeria
12Elasmobranch Research, Meistraat 16, 2590 Berlaar, Belgium
13Sezione di Zoologia ‘La Specola’, Museo di Storia Naturale dell’Università, Via Romana 17, 50125 Florence, Italy
14Shark Research Center, South African Museum, PO Box 61, 8000 Cape Town, South Africa
15Umhlanga Radiology, Radiology Department, Umhlanga Hospital, Private Bag X09, 4320 Umhlanga Rocks, South Africa
ABSTRACT: Age and growth of the basking shark Cetorhinus maximus (Gunnerus) was examined using vertebral samples from 13 females (261 to 856 cm total length [TL]), 16 males (311 to 840 cm TL) and 11 specimens of unknown sex (376 to 853 cm TL). Vertebral samples were obtained worldwide from museums and institutional and private collections. Examination of multiple vertebrae from along the vertebral column of 10 specimens indicated that vertebral morphology and band pair (alternating opaque and translucent bands) counts changed dramatically along an individual column. Smaller sharks had similar band pair counts along the length of the vertebral column while large sharks had a difference of up to 24 band pairs between the highest and lowest count along the column. Our evidence indicates that band pair deposition may be related to growth and not time in this species and thus the basking shark cannot be directly aged using vertebral band pair counts.
KEY WORDS: Basking shark · Cetorhinus maximus · Age · Growth · Vertebrae