METRIDIUM

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CLASSIFICATION OF METRIDIUM

KINGDOM :- ANIMALIA ( Multicellular eukaryotic organisms)

PHYLUM :- COELENTRATA OR CNIDARIA (Tissue grade, diploblastic and acoelomate. )

CLASS :- ANTHOZOA OR ACTINOZOA (Only polypoid generation. sedentary, solitary, colonial.)

SUB-CLASS :- HEXACORALLIA (Tentacles and mesenteries in multiple of five or six.)

ORDER :- ACTINIARIA (Sea anemones, without skeleton with mesenteries of septa in multiple of six. Basal disc present.)

FAMILY :- METRIDIIDAE (mesogloeal sphincter muscle and by the mesenterial arrangement)

GENUS :- Metridium (Common sea anemone)

It is largest and one of the commonest, sea anemones on the Atlantic coast, New Jersey to Labrador from low water mark to approximately 90 fathoms, Pacific coast and Europe.

Metridium is a large sessile, brightly coloured, solitary, flower-like or polyp-like marine coelenterate.

Commonly called as Sea anemone.
Body is short cylindrical, radially symmetrical and longer than broad.
Body of the animal is divided into 3 regions-Oral disk, column and pedal disk.
Oral disk is expanded as flat disk called as capitulum which is crowned with several marginal tentacles around mouth.
Column forms major part of the body and is differentiated into 2 parts:-
1. upper delicate thin walled capitulum and
2. lower thick walled scapus.
Capitulum and scapus are separated by a prominent fold called collar and a shallow grove called as fossa.
Wall of the scapus is perforated by small openings called as cinclides
Pedal disk : It is broad disk attached to substratum and is separated from scapus by limbus.
Dioecious: Sexes separate.
Asexual reproduction by budding and fragmentation.