CLASSIFICATION OF SPONGILLA
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 :- Spongilla
It is found in Atlantic, Europe and American waters.
HABIT AND HABITAT
Spongilla is a colonial sponge, abundantly found III ponds or streams.
GENERAL CHARACTERSTICS OF SPONGILLA
- Commonly known as fresh-water sponge.
- Colony is profusely branched, exhibiting various shades of green colour due to the presence of green algae, called as Zoochlorellae, in the cellular system.
- Body wall consists of very thin dermal membrane, perforated with dermal pores or ostia and several oscula.
- Skeleton is composed of spongin fibres. The siliceous spicules are in the form of network of smooth or spiny large and small oxe!lS, embedded in the spongin.
- Canal system is of the rhagon type. Water enters through dermal pores -> sub-> dermal cavity -> incurrent canals -> several flagellated chambers -> excurrent canal -> osculum.
- Asexual reproduction by gemmules.
- Sexual reproduction by sperm and ova.
- Gemmules are protected by amphidisk spicules.
- Larva is free swimming. It develops on floating submerged twigs or sticks.
The animal has branched colony, ostia, rhagon type canal system and all above features and hence it is Spongilla.