Xestospongia muta (Schmitdt, 1870)

Figs. 11 A–D, Tab. V

Schmidtia muta Schmidt, 1870: 44 –45.

Petrosia muta Topsent, 1920: 8, 33.

Xestospongia muta; Wiedenmayer, 1977: 115 –117, pl. XIV, Figs. 6–7, pl. XV, Figs. 1–2, text–Fig. 129; Zea, 1987: 111 –114, Fig. 32, pl. IX, Fig. 1; Lehnert, 1993: 47, Figs. 12–14, 69–70, tab. 1; Lehnert & Van Soest, 1996: 92; 1998: 75; 1999: 163.

Further synonymy: see Wiedenmayer (1977) and Zea (1987).

Examined material. MCNPOR 4773, 93 m 00°11’13”N – 44°46’12”W, 10/VI/1999; MCNPOR 4968, 4972, 4974, 4997, 4998, 94 m, 00°35’12”S – 43°20’55”W, 14/VI/1999 (MCNPOR 4974: fragment deposited in ZMAPOR 17914); MCNPOR 3799, 64 m, 01°03’S – 43°31’W, 30/XI/1997.

Material studied for comparison. Xestospongia muta (Schmidt, 1870): off the mouth of Amazon river. Fragment deposited on MCNPOR 2456 (det. Klaus Rützler).

Description. Cup­shaped specimen (Fig. 11 A): 16 cm long, 15 cm width, 11.5 cm height (MCNPOR 4773). Surface with sinuous elevations, smooth in between this. Thick walls, main vent with 4.5 x 5.0 cm in diameter. Preserved material with firm but brittle consistency, easy to cut or break, colour light brown.

Skeleton. Ectosome uni­ to multispicular tracts, forming triangular to rounded meshes, 130–260 µm in diameter, cemented with little spongin (Fig. 11 B). Choanosome: cavernous, with multispicular tracts (40–200 µm in diameter); rounded meshes 120–700 µm in diameter (Fig. 11 C). Many loose spicules, and in some areas the reticulation is dense and confused.

Spicules. Strongyles (Figs. 11 D): Slightly curved, equal and rounded ends. Measurements: 350–398–450 / 9.5–11.6–19 µm (MCNPOR 4773); 351.5– 389. 1 –418 / 9.5– 15. 2 – 19 µm (MCNPOR 4968); 300– 373. 2 –410 / 9.2– 13. 5 –16.1 µm (MCNPOR 4972); 285– 378. 1 –427.5 / 9.5– 14. 4 –19 µm (MCNPOR 4974); 247– 322. 2 –389.5 / 8.1– 10. 2 –13.8 µm (MCNPOR 4997); 228– 315. 4 –408.5 / 6.9– 10. 5 –13.3 µm (MCNPOR 4998); 280– 349. 2 – 430 / 7.5– 10. 2 –12.5 µm (MCNPOR 3799).

Remarks. Widely distributed species in the West Atlantic. With its cup­shaped form and fragile consistency it is a very conspicuous Xestospongia in this region. The present record from the coast of Maranhão State confirms its continuous distribution along with a record from the North Brazilian coast made by Collette & Rützler, 1977. The species was also previously recorded from deep water (Van Soest, 1980 and Lehnert & Van Soest, 1996).

Distribution. West Atlantic: Bermuda to Curaçao (Van Soest, 1980; Zea, 1987; Lehnert, 1993; Lehnert & Van Soest, 1996; 1998; 1999). Brazilian coast: off the mouth of Amazon River (Collette & Rützler, 1977); Maranhão State (present study).