CLASSIFICATION OF HALICHONDRIA
PHYLUM :- PORIFERA (Pore bearing, cellular grade, asymmetrical or radially symmetrical.)
CLASS :- DEMOSPONGIAE (Skeleton of spongin fibres or siliceous spicules which are not six-rayed.)
ORDER :- Monaxonida (Spongin mayor may not be present; spicules monaxon.)
GENUS :- Halichondria
Cosmopolitan, specially found in Rhode Island to Arctic ocean, North Pacific-Europe.
HABIT AND HABITAT
Halichondria is a colonial form. In shallow water it forms low encrustations on rocks while in deep water it develops into extensive masses of various kinds.
GENERAL CHARACTERSTICS OF HALICHONDRIA
- Commonly called as crumb of ‘bread sponge’.
- Soft green, brown or yellow coloured.
- Oscula are placed at the top of conical projection of sponge.
- In encrusting kinds, each osculum communicates with the surface and body is vase-shaped.
- In encrusting kinds each osculum communicates with the surface.
- Skeleton consists of irregularly scattered oxeas spicules of several sizes with little or no spongin.
The animal has massive colony, irregularly scattered spicules vase-shaped body, oscula and all above characters, hence it is Halichondria.