Morphometric Relationship and Condition Factor of Siganus stellatus, S. canaliculatus and S. sutor (Pisces: Siganidae) from the Western Indian Ocean Waters

Abstract

The rabbitfishes (Pisces: Siganidae) have long been considered good candidates for aquaculture. Some biological attributes including morphometric relationships (length-length, length-weight) and condition factors of three siganids of the Western Indian Ocean were estimated over peak April-August monsoon season in Southcoast Kenya. Specimens were caught using basket traps "malema", one of the main gears in the traditional fishery. A total of 64, 260 and 736 specimens of Siganus stellatus, S. canaliculatus and S. sutor were recorded, with mean±standard error for total length (TL) as 16.0±0.6cm, 22.5±0.3cm and 26.5±0.2cm with corresponding wet body weights (BWs) of 71.28±8.53g, 158.58±6.45g and 258.80±4.30g respectively. TL-BW relationships were best expressed by log10BW=2.597log10TL-1.356 for S. stellatus, log10BW=2.800log10TL-1.635 for S. canaliculatus and log10BW=2.716log10TL-1.484 for S. sutor with relative condition factors expressed by Kn = BW/ [(4.41x10-2) (TL2.597)], Kn = BW/ [(2.32x10-2) (TL2.800)] and Kn = BW/ [(3.28x10-2) (TL2.716)] for the three species respectively. TL and BW were significantly correlated with Kn and K. To the best knowledge of the authors, this study provides the first L-W relationship and Kn data for S. stellatus within the species geographical distribution. The overall results and equations provide useful simple tools for in-situ gauging of overall health of wild siganid populations in Southcoast Kenya for fisheries management and assessment of potential aquaculture species.