Showing papers on "Holothuria published in 2005"

Molecular Phylogeny of Coral-Reef Sea Cucumbers (Holothuriidae: Aspidochirotida) Based on 16S Mitochondrial Ribosomal DNA Sequence

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.

Holothurins B2, B3, and B4, new triterpene glycosides from Mediterranean sea cucumbers of the genus Holothuria

Abstract: Triterpene glycosides of three species of the Mediterranean sea cucumbers Holothuria polii, Holothuria tubulosa, and Holothuria sp. were studied. Three new monosulfated biosides, holothurins B(2) (1), B(3) (2), and B(4) (3), along with the previously known holothurins A (4) and B (5) were isolated from the sea cucumber H. polii. Triterpene glycosides belonging to holothurin A and B groups were found in H. tubulosa, while only one individual glycoside, holothurin A (4), was isolated from Holothuria sp. Structures of new substances were elucidated on the basis of spectral data (2D NMR and MS). The significance of holothurins as chemotaxonomic markers of the animals belonging to the genus Holothuria and taxonomic status of some representatives of the holothurians studied are discussed.

The cortical zone of skittle like cells of Urospora chiridotae, a gregarine from an apode holothuria Chiridota laevis

Abstract: Summary Electron microscopic study revealed a unique structure of the cortical zone of the skittle� like cells of Urospora chiridotae (Dogiel, 1906) Goodrich, 1925 (Eugregarinida: Urospo� ridae), a eugregarine from an apode holothuria Chiridota laevis Fabricius, 1720. The

Reproductive aspects, larval and Juvenile rearing of Holothuria (Theelothuria) spinifera Theel

Abstract: As in many Indo-Pacific countries, sea cucumbers form an important part of a mullispedes fishery in India. Beche-de-mer exported from India during the period 1992-2000, varied from 10.5 to 140 tonnes (t) and ranked first among the dried marine products. The beche-de-mer industry mainly depends on two spedes of Holothuria: H. scabra and H. spinifera. Beche-de-mer exports have declined from 70 t in 19%-1997 to 3.8 t in 2001. Due to overexploitation, the Ministry of Environment, Government of India, has banned both the fishing and export of sea cucumbers since June 2001.