Description

Description of the species: Shape: Individuals consist of tubes which can be stout-cylindrical, fusiform or slightly barrel-shaped, single or grouped, and topped by a large apical pseudoscule. Tubes can be as tall as 1 m, or more (up to 60 cm high and 9 cm wide on collected specimens). Smaller, presumably young individuals can be only 3 cm high and 0.8 cm wide. Tube walls vary from 0.5 to over 2 cm in thickness. These tubes can be smooth, finely conulose or very irregular, and many bear lateral projections (6 A – E), which vary from shallow-ridges and folds, to digitiform processes and lobes. All the tubes possess large apical pseudoscula 0.8 – 7.5 cm in diameter (Fig. 6 B, E), but small lateral oscula can be observed. In MNRJ 4164 and 4174 these pseudoscula have iris-type diaphragms, mainly in smaller tubes. These structures are commonly seen on live specimens, but easily lost on preserved material. In MNRJ 5471 and 5944, small digitiform projections (up to 1 cm high) rising from the large apical pseudoscula can be noticed. Live-colour is normally yellow or ochre-yellow (brownish). After preservation in ethanol, all specimens turned into purple, dark brown or black. The specimens are mostly very soft, apart from MNRJ 5471 which is very hard. Skeleton: Choanosome formed by an irregular polygonal reticulation of spongin fibers, 37 – 275 Μm thick (average 92 Μm; Fig. 6 D). They have an amber coloured bark, with the exception of specimen MNRJ 5471 which is reddish coloured. The pith can be black or amber, with thickness of 10 – 60 Μm (average 26 Μm; Fig. 6 E). TABLE III: Spongin fibres’ measurement data for Aplysina fistularis (Pallas, 1766) (in micrometers; S. D. = Standard Deviation and N = 30). Specimens Locality * Fibers Piths Thinnest Mean Thickest S. D. Thinnest Mean Thickest S. D. * BA, Bahia State; PE, Pernambuco State.

Common Names

Taxonomic Hierarchy

Kingdom: Animalia

Phylum: Porifera

Class: Demospongiae

Order: Verongiida

Family: Aplysinidae

Genus: Aplysina

Species: Aplysina fistularis (Pallas, 1766)