All echinoderms (Echinodermata),except holothurids, possess an axial organ (AO) as part of their coelomic and haemal system. Immunocytochemical positive reactions were observed in 1973 in the sea star Asterina gibbosa (Asterid, Echinoderm) [1]. After injections of various proteins. It seemed interesting to look for similar actions in the Ophuirid: Ophiocomina nigra (another echinoderm) which po...

The auricularia larva of sea cucumbers and tornaria larva of acorn worms share striking developmental and morphological similarities. They are regarded as not only an archetype of the nonchordate deuterostome larva, but also an archetype of the origin of chordates. Here we report the characterization and spatial expression patterns of the BMP-2/4 genes of a hemichordate acorn worm (Pf-bmp2/4) a...

Ophioderma peruana sp. n. is a new species of Ophiodermatidae, extending the distribution of the genus Ophioderma to Lobos de Afuera Island, Peru, easily distinguishable from its congeners by its peculiarly fragmented dorsal arm plates. Dense granules, rounded or polygonal cover the disc, the radial shields may be naked or completely covered by granules. A good character for recognizing this sp...

Taxonomic and biological aspects are presented on five species of shallow water holothurians from the Cayos Cochinos Biological Reserve-CCBR located on the northern Honduran shelf, western Caribbean at 16 degrees N, 86 degrees W. This article provides a taxonomic key of the recorded holothurians and morphometric/morphologic descriptions of their corresponding spicules. These five species belong...

Twenty four specimens of holothuroids recently received from the South African Environmental and Observation Network (SAEON), collected from off the south and west coasts of South Africa, are herein recorded and/or described. The specimens comprise eight nominal and one indeterminate species and represent both shallow-water and deep-sea forms, distributed from Plettenberg Bay to just north of L...

Thandar & Arumugam (2011), in their erection of the new dactylochirotid family Cucumellidae, inadvertently omitted to designate its type genus. This error is here rectified and Cucumella Heding (in Ludwig & Heding, 1935) is designated the type genus of the new family Cucumellidae to comply with the requirements of Article 61 of the International Code. Following Smirnov (2012), in his revised cl...

The mutable collagenous tissue (MCT) of echinoderms has the capacity to change its mechanical properties in a time scale of less than 1 s to a few minutes under the influence of the nervous system. Although accumulating evidence indicates that the mechanical adaptability of MCT is due primarily to the modulation of interactions between components of the extracellular matrix, the presence of mus...

The 1983-1984 mass mortality of Diadema antillarum produced severe damages on Caribbean reefs contributing to substantial changes in community structure that still persist. Despite the importance of Diadema grazing in structuring coral reefs, available information on current abundances and algal-urchin interactions in Cuba is scarce. We analyzed spatial variations in Diadema abundance and its i...