Population biology and diet of Stellifer rastrifer (Jordan, 1889), S. stellifer (Bloch, 1790) and S. brasiliensis (Schultz, 1945) (Perciformes, Sciaenidae) from Caraguatatuba Bay (SP)

Author(s)

Maira Pombo

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto Oceanográfico (IO/DIDC)
• Defense date: 2010-09-21

Examining board members

Alexander Turra; Paulo de Tarso da Cunha Chaves; Lucy Satiko Hashimoto Soares

• Advisor: Alexander Turra

Abstract

Intending to collaborate with some knowledge about ecosystems functioning for its suitable management and the conservation of natural resources, it was analyzed the populational dynamics and diet of three species belonging to the genus Stellifer (Sciaenidae), collected from August 2003 to October 2004, in shallow areas of Caraguatatuba Bay, where there was the least influence as possible of rivers and estuaries placed in the region. Species were Stellifer rastrifer (n=3183), S. brasiliensis (n=357) and S. Stellifer (n=116), wich focused at the southern area of the Bay. Species were significantly different from each other for size (S. rastrifer > S. stellifer > S. brasiliensis), although they have shown a quite similar pattern of length variation over time. They all fed upon basically crustaceans, with marked seasonal variation of food items and high dietary overlap among them. Stellifer rastrifer abundance allowed reproductive aspects analysis and the determination of growth parameters. The number of mature gonads in females was very small and gonadosomatic index values throughout the year were low, thus indicating that it is not a sapwn area. The growth parameters calculated (L?=20.9, K=0.37 and Z=2,81) indicate that there is a spatial segregation by size and that the mortality rate must, therefore, include a high rate of older individuals migration to deeper areas, where it is assumed that they complete their development. (AU)