Histological characterization of skin and radial bodies of two species of genus Isostichopus (Echinodermata: Holothuroidea)

Abstract

Surface morphological structure of the body, and radial organs in sea cucumbers Isostichopus sp. aff badionotus, Isostichopus badionotus morphotype I and I. badionotus morphotype II were characterized by histological techniques. The three morphotypes studied demonstrated differences between them in gross morphology and in the distribution of body fleshy projections in the dorsal region. The body wall consists of a layer of epidermal cells covered by a thin cuticle, a superficial dermis formed by a compact layer of cells with large cytoplasmic contents, slack dermis or delimited connective tissue into the body by a layer of muscle of circular lined by mesothelial cells. Radial bodies are made up of a nerve cord, two channels systems, a channel of water vascular system and five pairs of longitudinal muscles in the ambulacral region. Integument tissue structure showed no differences in the ventral or dorsal region. However, vascular channels through the integument give rise in the dorsal region to different fleshy protrusions wart-like, or fleshy papillae distinctive of each species while in the ventral region ends in podiums. Caribbean sea Isostichopus genus shows good quality skin structure and are able to be commercialized as sandfish or Bêche de mer in international markets. Keywords: Caribbean Sea, Collagen, Dermis, Isostichopus sp, Radial bodies