Age, growth and reproduction of the black sea bream Spondyliosoma cantharus (Linnaeus, ) (Sparidae) in the Gulf of Annaba (Algeria)

Abstract

Summary The objective of this study was to determine the basic population-specific parameters necessary for fish stock assessment in the Gulf of Annaba and to compare these with data from other Mediterranean regions. Black sea bream Spondyliosoma cantharus (Linnaeus, 1758) (N = 501) were collected monthly from January to December 2008 along the Algerian eastern coasts. More than 22 fish were collected each month and ranged in size from 13.4 to 40 cm total length, weighing from 36 to 1080 g eviscerated weight. Biological sampling included weighing and measuring the fish, gonad weighing, sex and maturity stage determination, and age estimation through otolith readings. Validity of the otolith readings for estimating age and growth was supported using the back-calculation method. Estimated parameters of the von Bertalanffy model are: L∞ = 33.54 cm, W∞ = 633.46 g, k = 0.52 year−1 and to = −0.04 year. The growth performance index (φ) is: 2.76. The length-weight relationship is: EW = 4.4.10−6 TL3.23. The spawning period occurred from February to May, while the gamete emission peaked in April. Females reached sexual maturity at 19.3 cm (2 years) and males at 21.3 cm (3 years). Sexual inversion occurs at approximately 24.3 cm. Spondyliosoma cantharus was characterized as being a protogynic hermaphrodite.