Barrel sponge

Xestospongia testudinaria

ORDER

Haplusclenda

FAMILY

Petrosiidae

TAXONOMY

Xestospongia testudinaria Lamarck, 1815, Cape Denison, Queensland, Australia.

OTHER COMMON NAMES

English: Great vase sponge, volcano sponge; German: Grosser Vasenschwamm.

PHYSICAL CHARACTERISTICS

A large erect reddish brown, barrel- or cup-shaped, thick-walled sponge as much as 4.92 ft (1.5 m) high, with prominent ridges or knobs at the surface. The upper edge of the cup is irregularly indented; the cup itself forms a conspicuous central cavity occupying as much as a third of the total height of the sponge. The sponge is firm and slightly compressible in consistency.

DISTRIBUTION

Western and Central Indian Ocean, Indo-Malesia, northeastern Australia, New Caledonia.

HABITAT

Reefs and lagoons, on rock or dead coral substrates.

BEHAVIOR

Little is known besides feeding ecology and reproductive biology.

FEEDING ECOLOGY AND DIET

Filter-feeder like all other sponges.

REPRODUCTIVE BIOLOGY

Individual sponges are of separate sexes. Mass release of the gametes takes place in September ('smoking' sponges), after which fertilization occurs in the sea water.

CONSERVATION STATUS

Not threatened.

SIGNIFICANCE TO HUMANS

A pleasure for snorklers and divers to find or collect.