''Holothuria leucospilota'', commonly known as the black sea cucumber or black tarzan, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of marine

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Holothuriidae Holothuriidae is a family of sea cucumbers, a type of echinoderm. Description Members of the family Holothuriidae have thick fleshy bodies and several rows of tube feet which are used for moving around and for adhering to the surface. The body ...

. It is placed in the

subgenus In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between t ...

''Mertensiothuria'' making its full scientific name ''Holothuria (Mertensiothuria) leucospilota''. It is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

of the subgenus and is found on the seabed in shallow water in the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

Description

''Holothuria leucospilota'' is a medium-sized sea cucumber reaching a length of up to when relaxed but it can stretch to about a metre (yard) when extended. It is roughly cylindrical, tapering towards the posterior end. At the anterior end, there are twenty oral tentacles with branched tips. These surround the mouth which is on the under side of the body. The animal is soft and pliable and is covered with fleshy papillae. The usual colour is charcoal grey or reddish-black with pale grey

tube feet Tube feet (technically podia) are small active tubular projections on the oral face of an echinoderm, whether the arms of a starfish, or the undersides of sea urchins, sand dollars and sea cucumbers; they are more discreet though present on britt ...

on the underside but off the African coast it is described as being bright or dark brown with white patches which are larger towards the posterior end.

Distribution

''Holothuria leucospilota'' is found in shallow water along the east coast of Africa and in much of the

region. It is a common species on the north east coast of Australia where it is found on reefs and rocky coasts, often partly concealed under a boulder. A study done near Singapore found that ''Holothuria leucospilota'' was more common near boulders, corals and seaweed clumps than it was on the open seabed. It found that this species is relatively tolerant of changes in salinity and temperature and continued to thrive in the laboratory when these parameters were changed. Under the same conditions, the Japanese sea cucumber (''

Apostichopus japonicus ''Apostichopus japonicus'' is a species of sea cucumber in the family Stichopodidae. It is found in shallow temperate waters along the coasts of south east Asia and is commonly known as the Japanese spiky sea cucumber or the Japanese sea cucumbe ...

'') shrank in size, eviscerated, and died within three days. In Singapore, ''Apostichopus japonicus'' is consumed as food and is becoming increasingly rare as a result of

overexploitation Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term app ...

Biology

''Holothuria leucospilota'' is a

scavenger Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding b ...

and when feeding it usually has its posterior end anchored underneath a rock or in a crevice so that it can contract back out of sight if disturbed. It feeds by using its tentacles to shovel organic debris lying on the seabed into its mouth. In the process it swallows a significant quantity of sand, which passes through the gut. If threatened, ''Holothuria leucospilota'' can emit a mass of fine sticky

Cuvierian tubules Cuvierian tubules are clusters of fine tubes located at the base of the respiratory tree in some sea cucumbers in the genera ''Bohadschia'', ''Holothuria'' and ''Pearsonothuria'', all of which are included in the family Holothuriidae. The tubules ...

from its anus which ensnare the potential predator allowing the sea cucumber to escape. It can regenerate these tubules in fifteen to eighteen days. The

worm pearlfish The worm pearlfish (''Encheliophis vermicularis'') is an eel-like fish in the family Carapidae. Description The worm pearlfish is typically 15 cm long and is characterized by its long, slender body and lack of scales. Morphology Worm ...

(''Encheliophis vermicularis'') is a parasite of this species and each parasitised ''H. leucospilota'' will host a male and female pair of the fish which live inside its body.

References

{{Taxonbar, from=Q910290 Holothuriidae Animals described in 1853