CLASSIFICATION OF ALCYONIUM
PHYLUM :- COELENTRATA (Tissue grade, diploblastic and acoelomate. )
CLASS :- ANTHOZOA OR ACTINOZOA (Only polypoid generation. sedentary, solitary, colonial.)
SUB-CLASS :- OCTOCORALLIA (Polyps with 8 tentacles, bioluminescent. )
ORDER :- ALEYONACEA (Basal part of polyp forms fleshy mass, while oral part distinct, sort corals.)
FAMILY :- ALCYONIIDAE (Lobed colony with retractile anthocodia.)
GENUS :- Alcyonium (Dead man’s Finger).
Alcyonium is cosmopolitan, but chiefly found in temperate and cold sea waters and specially form long Island Sound to Gulf of St. Lawrence and form low water to approximately 80 fathoms.
HABIT AND HABITAT
Alcyonium is marine sedentary and colonial animal. A1cyonaceans are typically littoral animals of warm water entering in the Indo-Pacific ocean. Many live between tidal zone at depth of approximately 200 m and few at a depth of approximately 3000 m. Number of species are found in temperate latitudes and even into Polar waters.
GENERAL CHARACTERSTICS OF ALCYONIUM
- Commonly called as soft coral.
- Colony consists of a base, stalk and a massive thick fleshy and leathery lobes or leathery branches.
- Fleshy mass is called as coenonchyma from which only oral ends of the polyps project.
- Usually the proximal part of the colony is devoid of anthocodia and is called sterile. In this animal anthocodia are strewn all over the distal part.
- Each polyp contains 8 pinnate tentacles.
- Spicules are found throughout the mesogloea which imparts solidity to coenenchyme.
- Fertilization is external.
- Life history includes a free-swimming planual larva, which becomes sedentary and forms colony by budding.
- The animal contains star shaped polyps in proximal part only hence it is Alcyonium.