CLASSIFICATION OF THYONE
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 :- Thyone
It is found in U.S.A. (Vineyard Sound and Southwards).
HABIT AND HABITAT
Thyone is a marine and burrowing animal in shallow waters. It is found buried in muddy and sandy bottoms.
GENERAL CHARACTERSTICS OF THYONE
- Commonly called as sea cucumber.
- Body is ovate or elongated.
- Oral end contains a large mouth, surrounded by 10 dendritic oral tentacles, which can be considerably extended. Tentacular region is followed by introvert.
- Colour may be dull brown or black or red above and whitish below.
- Body divided into ambulacral and interambulacral area.
- Tube feet are distributed over the entire body surface without definite arrangement in the ambulacral region.
- Respiratory trees present but cuvierian tubes absent.
- Haemal system simple. Haemocytes in the coelomic fluid contain haemoglobin. Stomach in the form of muscular sac.
- Water vascular system is present. Sexes are separate. Development includes Auricularia larva.
The animal contains small locomotory podia and all above features, hence it is Thyone.