We compared effects of exposure to predict near-future (2100) ocean acidification (OA; pH 7.7) and normal seawater (Control; pH 8.1) on immune and stress responses in the adult sea star Asterias rubens. Analyses were made after one week and after six months of continuous exposure. Following one week exposure to acidified water, the pH of coelomic fluid was significantly reduced. Levels of the c...

Echinoderms take many forms of symmetry. Pentameral symmetry is the major form and the other forms are derived from it. However, the ancestors of echinoderms, which originated from Cambrian period, were believed to be bilaterians. Echinoderm larvae are bilateral during their early development. During embryonic development of starfish and sea urchins, the position and the developmental sequence ...

Holopus mikihe new species is only the sixth extant holopodid crinoid to be described. It differs from all other extant holopodids in having large and distinct raised tubercles in the center line of the aboral surface of proximal secundibrachials, giving it the appearance of a mailed fist. The holotype, from 758 m, also comes from outside the known depth range of the other tropical western Atla...

A systematic account of crinoids from the Upper Coniacian-Lower Campanian of the southwestern margin of the Holy Cross Mountains in southern Poland is presented. Seven crinoid taxa [Marsupites testudinarius (von Schlotheim), Bourgueticrinus ellipticus (Miller), Bourgueticrinus sp., I.? granosus Valette, Isocrinus? sp., Nielsenicrinus carinatus Roemer and Austinocrinus bicoronatus (von Hagenow)]...

This review presents a comprehensive overview of the current status regarding the global diversity of the echinoderm class Ophiuroidea, focussing on taxonomy and distribution patterns, with brief introduction to their anatomy, biology, phylogeny, and palaeontological history. A glossary of terms is provided. Species names and taxonomic decisions have been extracted from the literature and compi...

The fossil record indicates that crinoids have exhibited remarkable regenerative abilities since their origin in the Ordovician, abilities that they likely inherited from stem-group echinoderms. Regeneration in extant and fossil crinoids is recognized by abrupt differences in the size of abutting plates, aberrant branching patterns, and discontinuities in carbon isotopes. While recovery is comm...

The general idea that emerged from the experiments, made in our laboratoires, was that Echinodermata, as exemplified by sea stars: Asterina gibbosa and Asterias Rubens, possessed an immune system, with B cell lymphocytes, able to mount cellular and humoral-specific responses, after stimulation with a foreign antigen [1]. Asterias Rubens produced ‘‘An antibody’’ anti HRP after injections to HRP,...

Echinoderm regeneration provides a convenient and tractable test to monitor the effects of persistent micropollutants on the developmental physiology of marine animals. Regeneration involves crucial and sensitive biological processes (cell proliferation, morphogenesis, differentiation, tissue renewal) that make it an ideal tool to assess micropollutants at the tissue and cellular level. Our res...