Porifera
Axinella pomponiae
(Brown Finger Sponge)
1. In situ (Rob Ruzicka)
2. In situ (Rob Ruzicka)
3. In situ - close up of oscules (Rob Ruzicka)
4. Out of water (Rob Ruzicka)
5. Out of water (Rob Ruzicka)
6. Out of water - Picture shows irregular distribution of oscules on surface (Rob Ruzicka)
7. Out of water - Picture shows irregular growth pattern at base of sponge (Rob Ruzicka)
Size
Colony height: reaching 30cm (12") Branch width: to 2cm (0.75")
Recognition Characters
Branching sponge. Branches are erect and flexible. Tapering towards tips and sometimes dichotomous at tips. Oscules have star-shaped pattern, are irregularly distributed but run length of branches. Surface appears superficially smooth but has numerous small pores evenly distributed throughout sponge. Spicules are styles of two sizes (long and short) and rarely contain oxeas. Sponge is very soft in consistency.
Color
Dark purplish-red or reddish brown when alive. Turns beige when preserved in alcohol.
Habitat & Depth
Temperate reefs to 50m. On mixed sandy and hard bottom habitats surrounding reefs.
Distribution at GRNMS
Common. Found on ledge tops and sandy bottoms adjacent to ledge.
Geographic Range
North Carolina south to Caribbean, Gulf of Mexico
Behavior & Notes
This sponge was formerly classified as Homaxinella rudis.
Synonyms
Homaxinella rudis
Wells et al. 1960, Alvarez et al. 1998