Aplysina cristagallus Pinheiro, Hajdu & Custódio, 2007, sp.n.

Aplysina cristagallus sp.n. (Fig. 9 C, 15, 16A)

Holotype: MNRJ 3528, Pedra do Silva (Reserva Extrativista de Corumbau, Prado, BA), 8 m depth, G. Muricy coll., 14/XI/1999.

Diagnosis: Thinly lamellar habit, similar to a rooster’s crest, covered by rows of small apical digitiform projections bearing a darker colour on their apices. Bluish gray colour in vivo, turning into a light shade of brown in ethanol.

Description:

The sponge is lamellar, somewhat resembling a rooster’s crest. It is 0.3 cm thick, 7 cm long and 7 cm high. The apical portion of the crest has many small apical digitiform projections 0.6 cm high (more than 50) distributed in rows. The small apical digitiform projections remain in the preserved specimen and show their apical portion darker than the base, which has the same colour of the rest of the sponge (Figs. 15A–B). In the upper part of the crest the sponge attains 1 cm in thickness. Small oscula appear on the apex and sides, where small projections are observed also bearing fistules on their top. The surface is very coarsely finely conulose. The colour is bluish gray in vivo (Fig. 9 C), which turns into a light shade of brown after preservation in ethanol. Consistency is very soft and flexible.

Skeleton: Choanosome with a delicate and irregular network of spongin fibers (Fig. 15C). Bark with amber colour and 46–232 Μm thickness (average 117 Μm). Thick, black or amber pith, 13–50 Μm thick (average 32 Μm; Fig. 15D).

Distribution: Provisionally known only from the type locality off the State of Bahia (Brazil; Fig. 16 A).

Bathymetry: The specimen was collected at 8 m of depth.

Etymology: The name of the species is a noun in apposition and recognizes its similarity with the rooster´s crest (crest = crista, and rooster = gallus in latin).

Remarks: The species which appears closest to A. cristagallus sp.n. is A. alcicornis sp.n .. Both possess a lamelar habit, less than 1 cm thick, with small apical digitiform processes. However, A. alcicornis sp.n. is stouter and has a harder consistency, is yellowish-brown in vivo becoming dark brown when preserved, and its small digitiform processes are larger, frequently ramified and located solely on top of projections. Moreover, the oscula on A. alcicornis sp.n. are situated inside depressions and are surrounded by iris-type membranes. In contrast, A. cristagallus sp.n. is rather slender and possesses a very soft consistency, is bluish gray in vivo turning into a light shade of brown after preservation, and presents more numerous fistules which are organized in crests and bear darker apical portions. Both species are thus considered well distinguished from one another.