Age and growth of &lt;em&gt;Spondyliosoma cantharus&lt;/em&gt; (Sparidae) in the Gulf of Tunis

Nejla Mouine-Oueslati,Romdhani Ahlem,Mohamed-Hédi Ktari,Nadia Chakroun-Marzouk,Chater Ines

doi:10.3989/scimar.04234.13a

Abstract

Age and the growth of the black seabream Spondyliosoma cantharus (Linnaeus, 1758) from the Gulf of Tunis were investigated using scales and otoliths. The length-weight relationship showed that the growth rates were isometric for females whereas males and the whole sample present a positive allometry. The monthly evolution in marginal increment data of scales and otoliths revealed that only one annulus is formed per year in April. Fish length and radii of the scales or otoliths were closely correlated. The von Bertalanffy growth equation was fitted on mean back-calculated length-at-age data, resulting in the parameter values L∞=35.4 cm, k=0.15 y–1 and t0=–0.19 y for scales and L∞=38.6 cm, k=0.10 y–1 and t0=–0.14 y for otoliths. Parameters estimated from scale and otoliths were significantly similar. However, taking into consideration the lower standard deviations of means for estimates based on otolith readings and the higher variance explained by the regression line fitted to otoliths, the latter seem to be more appropriate for ageing S. cantharus. The maximum age of the black seabream of the Gulf of Tunis is 10 years. Large discrepancies in growth parameters between geographic areas are the result of different growth patterns.

Highlights

The genus Spondyliosoma Cantor, 1849 is represented by one species in the Mediterranean Sea: the black seabream, Spondyliosoma cantharus (Linnaeus, 1758)
Because of the lack of basic biological information for the black seabream in Mediterranean, the objective of this study is to provide information on the age and growth of this species in the Gulf of Tunis
The analyses of covariance (ANCOVA) test indicated that lengthweight relationships were not significantly different in slopes or intercept between the two sexes (ANCOVA, n=345; p>0.05)

Summary

Introduction

The genus Spondyliosoma Cantor, 1849 is represented by one species in the Mediterranean Sea: the black seabream, Spondyliosoma cantharus (Linnaeus, 1758). This species, belonging to the Sparidae family, occurs in the eastern Atlantic from Scandinavia to Namibia and around the Madeira, Cape Verde and Canary Islands (Heemstra 1995); it is common in the Mediterranean Sea and rare in the Black Sea. The black seabream is a relatively common fish of inshore waters on rocky and sandy bottoms (Bauchot and Hureau 1986). Mouine-Oueslati et al. Despite the wide distribution of S. cantharus, the majority of biological studies, in particular on reproductive aspects, have been reported from the eastern Atlantic (Perodou and Nedelec 1980, Soletchnik 1983, Balguerías Guerra et al 1993, Pajuelo and Lorenzo 1999, Gonçalves and Erzini 1998). In the Mediterranean Sea, some aspects of black seabream growth (Dulčić and Kraljević 1996), recruitment (Guidetti and Bussotti 1997), fecundity (Dulčić et al 1998) and reproduction (Mouine et al 2011) have been described

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Discussion

Conclusion