The Proximate Composition and the Nutritional Value of Some Sea Cucumber Species Inhabiting the Sudanese Red Sea

Some biochemical studies (protein, fat, moisture and ash) were done on three species of holothurians namely Holothuria scabra, Actinopyga echinites and Holothuria atra, which were collected from Abu Hashish and Kilo Tammania areas in Sudanese Red Sea. Statistical analysis showed that there was a significant difference (P<0.05) in moisture, ash and protein content of the air-dried and processed animals. However, a non-significant difference (p>0.05) in fat content is encountered. Differences in moisture and fat content of H. atra collected from the two sites are insignificant while the difference in protein and ash contents are significant. All the measured contents in A. echinites are assumed not to differ significantly between the two areas except in their fat content. Keywords: holothurians, sea cucumber, biochemical, Red Sea, Suda

Functional study of the pectoral spine stridulation mechanism in different mochokid catfishes

International audienceMochokidae are able to produce pectoral spine stridulation sounds. During sound production, high speed videos were used to study the pectoral fin movements to identify the mechanisms involved. A call consisted of a series of pulses and occurred during a spine sweep, which was in fact made up of a series of jerky movements. The morphology of the pectoral spines and associated muscles was also observed in different species. The contractions of adductor profundus and superficial adductor allows adduction and abduction movements (sweep) of the spine, respectively. Simultaneously, the contraction of the arrector ventralis or the arrector 3 of the pectoral spine allows the pulling and pressing the ridges of the dorsal process, against the rough lateral face of the spinal fossa. This results in the rubbing of the ridges of the dorsal process, producing sounds. In Synodontis the analogy for sound production would be a brake shoe pressing against a wheel