Holothuria scabra, or sandfish, is a species of sea cucumber in the family Holothuriidae. It was placed in the subgenus Metriatyla by Rowe in 1969 and is the type species of the subgenus. Sandfish are harvested and processed into "beche-de-mer" and eaten in China and other Pacific coastal communities. Sea cucumbers are marine invertebrates and are closely related to sea urchins and starfish. All these groups tend to have radial symmetry and have a water vascular system that operates by hydrostatic pressure, enabling them to move around by use of many suckers known as tube feet. Sea cucumbers are usually leathery, gherkin-shaped animals with a cluster of feeding tentacles at one end surrounding the mouth. Anatomy and morphology The sandfish has the same basic anatomy as most other species of sea cucumber. Their bodies are elongated and cylindric, and relatively stubby. Their dorsal side can range in color from a grey-brown to black, with darkened wrinkles across the body and small black papillae from end to end. They are counter shaded with a lighter ventral side, which is relatively flat. They have a mouth located on the ventral surface at one end of the body, considered the front end. Like other sea cucumbers, they use feeding tentacles which protrude from the mouth. Sandfish have around 20 short tentacles. On the opposite end the anus is found on the dorsal side. They can grow up to an average length of 22 cm with the largest reaching up to 40 cm, and reach maturity around 16 cm or 200 grams with some growing as much as 300 grams in one year. It is unknown how long they live undisturbed, but they can live to at least 10 years. Their gonads are found through a single genital orifice on their dorsal anterior end. Their digestive system is made up of a mouth, an esophagus, a stomach, an intestine, a cloaca, and an anus. They extend respiratory trees from their cloaca in order to breathe. Their body wall is thick, making up a total of 56% of their weight. This body wall is filled with calcareous plates called spicules, and are used to ID species; the sandfish is identified by table and knobbed button shapes. Like other sea cucumbers, they can eviscerate their internal organs if they undergo stress, and can regenerate their organs; in sandfish this takes about 2 months. Life cycle The