Sponges

Taxonomic group

Phylum: Porifera

Diagnostic features

Sponges are very basic animals with no circulatory, digestive or nervous systems. Their structure involves a tubular network that allows water to flow through their bodies bringing food and oxygen. Their growth form may be mounds or mats attached to hard surfaces, and often they have a crunchy texture due to a “scaffolding” of mineral spicules.

Sponge on [Potamopyrgus] snail. Image: Stephen Moore Image — Sponge on Potamopyrgus snail. Image: Stephen Moore

Sponge. Image: Stephen Moore Image — Sponge. Image: Stephen Moore

Typical habitats

Sponges attach to hard surfaces in streams, most commonly stones but sometimes woody material or snail shells.

Feeding

Sponges usually feed on microscopic floating food particles including bacteria, but some have symbiotic algae growing within the sponge generating organic matter internally.

Indicator value

Sponges are common in habitats with good water quality, but also in urban streams with obviously degraded water quality. No tolerance values have been assigned.