Benthodytes

Benthodytes is a genus of sea cucumbers in the family Psychropotidae.^[3]

Benthodytes
Benthodytes sanguinolenta[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Echinodermata
Class:	Holothuroidea
Order:	Elasipodida
Family:	Psychropotidae
Genus:	Benthodytes Théel, 1882[2]

Discovery

This group of sea cucumbers was first described by scientists aboard the H.M.S. Challenger during its 1873-1876 voyage.^[4] Théel described the genus: "Body more or less depressed, with the anterior part of its brim rather large. Mouth ventral, at a greater distance from the foremost extremity of the body. Anus posterior, dorsal, usually almost terminal. Tentacles (?) twelve to twenty. Pedicels arranged in a single row round the brim of the body and in a double one along the odd ambulacrum. The dorsal surface seldom naked, commonly with a greater or smaller number of retractile or non-retractile, more or less inconsiderable processes, arranged in a single row all along each ambulacrum or in an irregular double row, or scattered over the lateral interambulacrae."^[4] Théel also documented the details of species B. typica, B. sanguinolenta, and B. abyssicola.^[4]

Anatomy

Among Psychropotidae, Benthodytes (synonym Benthodites) are characterized by "soft retractile tentacles, circum-oral or post-oral papillae and the absence of an unpaired dorsal appendage."^[5]

Significance

Several species of Benthodytes are good indicators of the potential impacts of deep-sea mining and have been the subject of multiple studies.^[6][7] Identification of distinct species is most often based on photography, since the delicate anatomy of the sea cucumbers is often damaged in the process of sampling.^[6] Genome sequencing technology is paving the way for more accurate accounts of the evolution and taxonomy of Benthodytes species, starting with B. rosea and B. typica.^[8] Additionally, the mitochondrial genome of B. marianensis has been sequenced and was found to contain a novel gene arrangement among holothurians that could be an adaptation allowing for survival at great depths.^[9]

Species

Several species included in the genus Benthodytes have been reclassified using different nomenclature.^[10] This list is subject to change as phylogenetic data clarifies the relationships among difficult-to-identify creatures whose soft appendages are often lost in the process of sample collection.^[11]

• Benthodytes abyssicola
• Benthodytes gosarsi
• Benthodytes incerta
• Benthodytes lingua
• Benthodytes manuensis
• Benthodytes marianensis
• Benthodytes plana
• Benthodytes sanguinolenta
• Benthodytes sibogae
• Benthodytes superba
• Benthodytes typica
• Benthodytes valdiviae
• Benthodytes violeta
• Benthodytes wolffi