Age and growth of the Scalloped Hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834), from the southern Brazilian coast

Author(s)

Kotas, J. E. ^[1] ; Mastrochirico, V ^[2] ; Petrere Junior, M. ^[3]

Affiliation

^[1] Ctr Pesquisa & Gestao Recursos Pesqueiros Litoral, BR-88301280 Itajai, SC - Brazil

^[2] Fundacao Univ Fed Rio Grande FURG, Dept Oceanog, BR-96201900 Rio Grande, RS - Brazil

^[3] Univ Estadual Paulista UNESP, Inst Biociencias, Dept Ecol, BR-13506900 Rio Claro, SP - Brazil

• Document type: Journal article
• Source: Brazilian Journal of Biology; v. 71, n. 3, p. 755-761, AUG 2011.
• Web of Science Citations: 6

Abstract

Age and growth studies for the scalloped hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834) caught along the southern Brazilian coast, were based on ring measurements of vertebrae sections of 115 males, 116 females and 14 unknown sexed sharks between 48 and 344 cm total length (TL). The von Bertalanffy growth models were best fit using back-calculated data. The growth parameters obtained for males, were L(infinity) = 266 cm; K = 0.05/year; L(0) = 47 cm. For females, L(infinity) = 300 cm; K = 0.05/ year; L(0) = 51 cm. An adult female reached 217 cm TL and was 31.5 years old. On the other hand, an adult male was 29.5 years old and measured 234 cm TL. Longevity estimate for males and females was 55 years. Therefore, S. lewini is a long-lived fish. Ageing precision, based on the IAPE index, was 5.6%. Marginal Increment analysis based on MIR index from hammerheads smaller than 105 cm, compared with the percentual of opaque and hyaline bands found per month ageing whole vertebrae, showed an annual ring formation, i.e., in winter. (AU)

• FAPESP's process: 01/13299-7 - Population dynamics, ecology and fisheries of aquatic beings
• Grantee: Miguel Petrelli Junior
• Support Opportunities: Research Projects - Thematic Grants