LollyfishHolothuria atra
Category
- Seagrass
Description
This sea cucumber is commonly known as the Lollyfish or Black sea cucumber. It is the most abundant of Holothurians. It is an invertebrate which has a sausage shape and can grow up to 60cm. It possesses a black smooth skin, often with sand stuck to it. The mouth is found at one end, on the underside, with 20 black tentacles surrounding it. The opposite end is the anus. Males and females cannot be distinguished based on external morphology. A black polychaete worm, Gastrolepidia clavigera, often accompanies this sea cucumber. Lissocarcinus orbicularis a small crab can also be found living with these Lollyfish[1].
[1] Abdel-Razek and Abdel-Razek, F.A. et al., ‘Reproductive Biology of the Tropical Sea Cucumber Holothuria Atra (Echinodermata’; Paulay, Gustav and Paulay, Holothuria (Halodeima) Atra Jaeger, 1833.
Habitat and ecology
This species is present across the Indo-Pacific region, from the Red Sea, to Hawaii and Eastern Pacific. It is also found near South East Arabia, Persian Gulf, Maldives, Bay of Bengal, Australia. China, Japan, South Pacific and India. This species can be found in a wide range of habitats in water not more than 20m deep; coastal lagoons, intertidal areas, water less than a metre deep or exposed on the sand and can tolerate water of high temperatures.
It can camouflage itself by covering its body with sand and as a defence mechanism releases a toxic red fluid when its skin is rubbed, it can also expel some of its inner organs out through its anus which are also toxic to predators.
This Lollyfish is an omnivore; it sifts through sand with its tentacles and feeds on dead organic matter. It takes in sand simultaneously and digests biofilm present on the sand particles prior to releasing the sand through the anus. They play an important ecological function in removing dead organic matter and redistributing sediments in their habitat.
Spawning varies according to location; in Fiji, it occurs between September and December and in warm waters, it can occur all year round. Asexual reproduction through transverse fission is common among smaller individuals; a groove forms in the middle of one individual that slowly separates into two.
Conservation and management
According to the IUCN Red list, this species is categorized under the ‘Least Concern’ category. It is widespread in the Indo-Pacific oceans and abundant in many areas. It is of major commercial importance, even in Mauritius. Overexploitation is a potential threat. In certain countries, for example, Nicobar Islands, collect has been banned. In Maldives and Australia, there is a collect size limit.
In Mozambique, there are regular closures in order to allow population to grow. This species could potentially be present in certain MPAs over part of its range[1].
Did you know?
Holothurians are the subject of scientific studies in order to extract bioactive agents. It has been proven that they possess compounds that have anti-tumour, anti-fungal and anti-viral properties[1].
