''Polymastia fusca'' is a species of

sea sponge Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through t ...

belonging to the family

Polymastiidae Polymastiidae is a family of demosponges found in oceans throughout the world. It is the only family in the monotypic order Polymastiida. A useful diagnostic characteristic of members of this family is the presence of numerous surface papillae ...

. It is found in shallow subtidal habitats in the far north of

North Island The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but much less populous South Island by the Cook Strait. The island's area is , making it the world's 14th-largest ...

, New Zealand. This firm-textured sponge grows up to 20 cm across, often encrusting its substrate. The outer layer is very dark brown, contrasting with a much paler yellow or orange interior. The whole surface is covered in

papilla Papilla (Latin, 'nipple') or papillae may refer to: In animals * Papilla (fish anatomy), in the mouth of fish * Basilar papilla, a sensory organ of lizards, amphibians and fish * Dental papilla, in a developing tooth * Dermal papillae, part of ...

e, those at the centre markedly taller than those at the periphery.

References

* fusca Sponges of New Zealand Animals described in 1961 Taxa named by Patricia Bergquist {{demosponge-stub