Données biologiques et valeur nutritive de la paroi d’Holothuria Polii (Delle Chiaje, 1823) (Holothuroidea Aspidochirotida) des iles Kerkennah (golfe de Gabes, Tunisie)

Abstract

This study concern Holothuria polii population from Tunisian coasts with a view to highlight its biological and nutritional characteristics. Sampling of the species was carried out monthly for one year on the western coast of the Kerkennah Islands. A total of 329 individuals were collected and measured. The mean value of the total length (LT) of the species is 111,2 ± 19,44mm, the total weight (PT) 44 ± 16,28g and eviscerated weight (PE) 19,4 ± 5,41g. All size-weight relationships showed that the increase in weight is less important than the increase in length. The allometric relationship of total length to eviscerated total weight showed the highest correlation coefficient r = 0,86. The reproductive cycle of the species is closely linked to temperature. The gonad index (GI) suddenly reaches its maximum in May and the spawning begins immediately in June and continues until August. From a nutritional point of view, the analysis of the fresh wall of Holothuria polii shows a very high rate of water (87,77%) but has a significant proportion of mineral matter (3,16%). Also, the muscle contain high levels of protein (7,85%) compared to fat contents (0,82%).