Holothuroidea - Introduction, characteristics, phylogenetic relationships and fossil history of the sea cucumber, from the Tree of Life Web Project. Cucumber Defenses - Rob Toonen's comments about the defense mechanisms of sea cucumbers. Athyonidium chilensis - Images and brief information about this Chilean species (Dendrochirotida: Cucumariidae). Sea Cucumbers - Class Holothuroidea - Description and interesting facts. Holothuroidea - Sea Cucumbers - Overview, including characteristics, taxonomy, phylogenetic relationships, and fossil history. Holothuria forskali: Black Sea Cucumber - Photographs and a description of this species. Cotton-Spinner (Holothuria forskali) - Whilst diving round the coasts of Britain, Jane Lilley observed this sea cucumber and its behavior. Sea Cucumber: Holothuria pardalis - Research project by Ka Wai Hui on this species, including its classification, habitat, reproduction, nutrition, adaptations and use to humans. Thyonella gemmata - Taxonomy and photograph of this shallow-water sea cucumber. Istichopus badionotus - Taxonomy, description and photograph of this sea cucumber. Holothuroidea - Wikipedia article on this class of marine animals, the sea cucumbers, with elongated bodies and leathery skin. Cucumaria frondosa - Exercise from Invertebrate Anatomy OnLine covering the systematics, external and internal anatomy of this sea cucumber. Sclerodactyla briareus - Exercise from Invertebrate Anatomy OnLine covering the systematics, external and internal anatomy of this sea cucumber, with notes on Cucumaria. ADW: Class Holothuroidea - Photographs and information on the sea cucumbers from the Animal Diversity Web.