CLASSIFICATION OF EPHYDATIA
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 :- Ephydatia
Found in Vancouver Island, Eastern and Central States.
HABIT AND HABITAT
Ephydatia is a greyish or greenish fresh-water sponge, found in clear water in streams, rivers, ponds and lakes. It attaches itself over rocks, twigs, plants or seed stems and sticks.
GENERAL CHARACTERSTICS OF EPHYDATIA
- Body of the animal consists of delicate chimney like tubes or finger like outgrowths.
- At the end of each chimney lies an osculum.
- Surface is perforated by several large oscula and large number of pores or ostia.
- Scattered monaxon spicules are protective. Amphidisk spicules present.
- Food consists of organic particles, unicellular plants and infusorians.
- Species growing in bright light acquire a greenish colour due to intracellular symbiotic Zoochlorellae
- McNair found that stimuli applied at the oscular rim would be transmitted down the chimney, resulting in contraction or collapse of the latter. It shows sensory nature of the osculum.
- Asexual reproduction by gemmules.
The animal has pores, oscula, chimney like tube and all above features and hence it is Ephydatia.