Description: Shape is subtubular, like a vertically folded fan partially fused, becoming a not completely closed tube, up to about 8-10 cm tall and 3 cm in the widest, being narrower towards the base. At the apex there is a membranous oscule, whose membrane may extend downwards partially closing the gap between the folded walls. The surface is strongly corrugated with rather symmetrical, blunt and slightly flattened lamellae. Color orange-yellow. Consistency toughly compressible. Spicules are styles in two categories, one long and another smaller, and oxea, larger than the smaller styles.
Notes: This is a deep reef exposed sponge. Initially, we were including the subtubular specimens as part of the variation of A. corrugata (George & Wilson, 1919), also pictured here, owing to the similarity in spiculation. As the external shape of the pictured specimens is characteristic and very similar to A. digitiformis, described from the deep reefs of Jamaica, we decided for the time being to use this name tentatively to draw attention to their similarities and differences. A. corrugata specimens are less erect, and tend to be bushier, with lamellae often larger and often arranged as folds that run vertically from base of the sponge. Unfortunately, after examining spicules of this species in fresh, we did not keep material for further comparisons.
Molecular studies have found that the genus Axinella is polyphyletic, with members spread throughout several families and even orders of Demospongiae (Alvarez et al., 2000; Gazave et al., 2010; Morrow et al., 2012; Redmond et al., 2013). We have decided to maintain the name Axinella for this species until further studies show to which group it belongs.
Author Reference: Lenhert & van Soest, 1996
Link: World Porifera Database