CLASSIFICATION OF HOLOTHURIA
PHYLUM :- ECHINODERMATA (Coelomate, pentaradiate and spiny skinned animals with vascular system.)
SUB-PHYLUM :- ELEUTHEROZOA (Non-pedicellate and free-living.)
CLASS :- HOLOTHUROIDEA (Body orally and aborally elongated.)
ORDER :- DENDROCHIROTA (Oral tentacles tree-like – dendroid.)
GENUS :- Holothuria (The sea cucumber)
It is found in India, Florida and West Indies.
HABIT AND HABITAT
Holothuria is found near seacoasts and is measuring about 30 cm. The animal feeds on microorganisms and moves very slow on the sea bottom by the muscular contractions of the body wall and with the help of its tube feet.
GENERAL CHARACTERSTICS OF HOLOTHURIA
- Commonly called as sea cucumber.
- Body is elongated along the oral and aboral axis horizontally.
- Oral end has large mouth surrounded by tactile buccal tentacles for collecting food.
- Madreporite is internal polian vesicles 1 to many. Water vascular system well developed.
- Tube feet contains suckers and are present in rows. Body divided into ambulacral and interambulacral areas.
- Dermo-muscular body wall is embedded with small calcarious ossicles.
- Pedicellariae or spines absent.
- Respiratory tree and cuviers tubes are present internally.
- Ambulacral grooves are covered and run longitudinally.
- Sexes are separate. Development includes Auricularia larva which develops into Doliolaria before metamorphosis into adult.
The animal contains small buccal tentacles and all above features, hence it is Holothuria.