black
brown
encrusting
papillated
tough
Bahamas
Polymastia tenax
Notes: This sponge appears as reddish brown groups of large papillae surrounding tall membranous oscules, filling crevices or growing among coral branches. It is very tough and the papillae contract upon contact. Very probably this species is a junior synonym of Polymastia nigra Alcolado, 1984. Upon confirmation, the latter name would have priority. Another species that may be conspecific with these is P. fordei Lehnert & van Soest, 1999. Spicule lenght and thickness and degree of development of subtylostyle spicule head appear to vary geographically, generating confusion.
Author Reference: Pulitzer-Finali, 1986
Link: World Porifera Database