Asexual reproduction, evisceration, and regeneration in holothurians (Holothuroidea) from Nha Trang Bay of the South China Sea

Abstract

Peculiarities of asexual reproduction, evisceration, and regeneration were studied in 13 holothurian species of the orders Dendrochirotida and Aspidochirotida from Nha Trang Bay of the South China Sea. Asexual reproduction by fission has been described for the first time for Cladolabes schmeltzii. It has been shown for the first time that transected C. schmeltzii and Colochirus robustus successfully regenerate not only their anterior, but also their posterior structures. It was found that Pseudocolochirus violaceus was able to regenerate the anterior part of the body and to eject viscera through the anus. The modes of evisceration and regeneration of the gut have been elucidated for ten species of aspidochirotids. It has been shown that the intestine of Holothuria scabra forms from two anlagen rather than from a single one, as previously believed.