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Sponge; Orange Encrusting

Sponge; Orange Encrusting

Hemimycale sp.

Despite being fairly widespread in southern Australia the orange encrusting sponge is still undescribed, and as a consequence very little is known about this species.  The orange encrusting sponge is a multicellular animal that lives attached to marine reefs.  It usually bright orange or red, but may be pale grey to brown.  It grows over branches of the telesto coral, appearing to be part of the soft coral, and also cup corals, barnacles whose defences are often effective against the smothering of sponges.  Similarly to other sponges, the orange encrusting sponge is specially adapted for a sedentary, filter feeding life.  The surface of the orange encrusting sponge is perforated by numerous pores (ostia) through which water is drawn in, plankton becomes trapped within the feeding chamber and waste water is expelled through larger openings (oscules).  Thousands of litres per day are pumped and filtered though sponges.  Sponges are hermaphroditic, meaning that individuals produce both sperm and eggs, though they can reproduce both sexually where an egg is fertilised by sperm producing larvae, or by asexual reproduction by producing a new animal from pieces broken off from a parent sponge.

Occurrence at the Busselton Jetty: 

The orange encrusting sponge is widespread on the jetty piles, and can be observed only a few metres from shore.

Image by: O. Rynvis