Actinopyga

Abstract: Members of the Holothuriidae, found globally at low to middle latitudes, are often a dominant component of Indo–West Pacific coral reefs. We present the first phylogeny of the group, using 8 species from the 5 currently recognized genera and based on approximately 540 nucleotides from a polymerase chain reaction–amplified and conserved 3′ section of 16S mitochondrial ribosomal DNA. Parsimony and likelihood analyses returned identical topologies, permitting several robust inferences to be drawn. Several points corroborated the Linnean classification. Actinopyga and Bohadschia each appear monophyletic and Pearsonothuria is sister to Bohadschia. Other aspects of our phylogeny, however, were not in accord with the taxonomy of Holothuriidae or previous speculations about the group’s evolutionary history. Most notably, the genus Holothuria appears paraphyletic. Actinopyga and Bohadschia, sometimes held to be closely related to one another because of certain morphologic similarities, are only distantly related. The morphologically distinct Labidodemas, even thought to warrant separation at the family level, is nested well within Holothuria. A maximum parsimony reconstruction of ancestral ossicle form on the phylogeny indicated that, in addition to a probable bout of elaboration in ossicle form (the modification of rods or rosettes to holothuriid-type buttons), at least 2 rounds of ossicle simplification also transpired in which buttons reverted to rods or rosettes. Cuvierian tubules, defensive organs unique to numerous members of Holothuriidae, were probably present before the initial radiation of the family, but the reconstruction is ambiguous as to their ancestral function.

Abstract: Collections of echinoderms were made from the intertidal, lagoon and reef slopes of Rodrigues over a period of 3 weeks in September to October, 2001. A total of 74 species are reported here, including three species of Crinoidea, 10 species of Asteroidea, 17 species of Ophiuroidea, 15 species of Echinoidea and 29 species of Holothurioidea. These findings include 10 new records for the Mascarene Islands (Reunion, Mauritius and Rodrigues), four species (two in the asteroid genus ‘Asterina’, one in the ophiuroid genus Amphioplus and one species in the holothurioid genus Actinopyga) that remain unnamed due to the need to clarify unresolved taxonomic issues, and one species of crinoid which could not be identified because only the distal parts of four arms were collected. In the dendrochirotid holothurioid family Psolidae, the little-known species Psolus appendiculatus (de Blainville) 1821, P. boholensis Semper, 1868 and P. complanatus Semper, 1868 are referred to the genus Psolidium Ludwig, 1887. Despite its s...

Abstract: Coastal waters of Pakistan have considerable biodiversity of sea cucumbers and to date 11 genera and fifteen species of sea cucumbers belonging to 3 families have been recorded. In the present study the biochemical composition and nutritional quality of two most common sea cucumbers (Holothuria arenicola and Actinopyga mauritiana) were determined. The study includes their proximate, amino acid, and fatty acid compositions. The protein content of Actinopyga mauritianais ~ 67 % comparatively higher than that of Holothuria arenicola, in which it was ~ 45 %. The high value for ash content was found in H. arenicola i.e. ~45 % in comparison to ~32 % in A. mauritiana, The lipid content was not significantly different in the two species and attained values of 0.88 % and 0.76 % in H. arenicola and A. mauritiana, respectively. The total fatty acids were determined for both the species in which findings suggested that polyunsaturated fatty acid ( PUFA) was more than saturated fatty acid ( SFA) and monounsaturated fatty acid (MUFA). Results also showed that eicosapentaenoic acid (EPA; 20:5ω3), arachidonic acid (AA; 20:4ω6) and docosahexaenoic acid (DHA; 22:6ω3) are dominant among all PUFA. All the essential amino acids were found in both the species in which Glycine was found as major amino acid. Profile also suggested that Lysine/Arginine ratio was in favorable range to produce Hypocholesterolemic and antiatherogenic effects. Both the species of sea cucumbers are potential source of macro and micro nutrients with having no toxic elements under studied. .