Holothuria leucospilota

                                   Holothuria leucospilota

                                                                  Kingdom: Animalia

                                                                  Phylum: Echinodermata

                                                                  Class: Holothuroidea

                                                                  Order: Aspirochirotida

                                                                  Family:Holothuriidae

                                                                  Genus : Holothuria

                                                                  Species: leucospilota

                                                                 Author: Brandt, 1835

Tentacles with bush like branchinges  

Photographed at Manadhoo,
Noonu Atoll, Maldives 

Sea cucumbers are echinoderms, a group of spiny skinned marine organisms which includes also sea stars and sea urchins. They are known for their leathery skin, elongated cucumber shape body and the fact that they are eaten as delicacy in some Asian countries. For this last reason, they are heavily poached in many countries, and some species are in danger of extinction. Black long sea cucumber is one among them known for its black colour with long stretchable body. It is characterized by charcoal black colour with soft cylindrical body covered with soft papillae. The length ranges from 30 -40 centimetres when it is relaxed; but, biggest specimens can stretch their body up to 60 centimeters. The posterior end of the cucumber is tapered and anterior end possesses 20 branching tentacles with surrounding the mouth. H. leucospilota is one of the common species that is distributed throughout the Indo pacific, Central America, east coast of Africa, Red Sea and north east coast of Australia. Like most holothurians, they are scavengers that collect the sand and separates bio film and organic matter; they feed on diatoms, bacteria and microalgae.  It is a shallow water cucumber found in rocky shore and coral reef areas distributed within 5 meters and maximum up to 20 meters depth. According to IUCN it is one of the most abundant species of sea cucumber with to H.atra.
 

Cuvierian tubules

There are clusters of tubules located at the base of respiratory tube that lie freely in the coelomic fluid in the body cavity named Cuvierian tubules. There may be lot of questions for readers on why it is named Cuvierian and what these tubules are. It’s because it is named after the French 19th century zoologist Georges Cuvier who described it first. These are sticky tubules that are released by a sea cucumber to avoid the predator when it gets threatened.  When the sea cucumber gets stressed it contracts its body causing cloacal wall to tear and release of tubules through anus. As soon as the thread reaches the sea water it extends due to forcing of water from respiratory tree of sea cucumber and becomes more adhesive. The tubules have the capacity of expanding 20 times of their actual length. Like lizards tail, the tubules can be regenerated and regeneration time varies from one species to another in case of H.leucopilota it takes 15-17  days to regenerate the tubules

Human vs H.leucospiloata

H.leucospilota is consumed in Fiji, Solomon Islands, Tonga, Cook Islands, Guam and Marshall Islands. Though, this species widely consumed in western pacific region, it doesn’t fetch high commercial value. This species proved to be surviving in wide range of temperature, salinity and other physiochemical factors that makes high volume of its population. So far, the population is listed in least concern in IUCN red list, but there is high possibility for exploitation of this species since the population of higher commercial value species is getting depleted. 

Acknowledgement 

Information where collected from the following references

http://species-identification.org/species.php?species_group=nasc&menuentry=soorten&id=65&tab=beschrijving

http://www.iucnredlist.org/details/180375/0