Neopetrosia subtriangularis (Duchassaing, 1850)

Figs. 9 A–D

Spongia subtriangularis Duchassaing, 1850: 26 .

Xestospongia subtriangularis; Wiedenmayer, 1977: 113, pl. XIV, Figs. 1–5, text­Fig. 128; Van Soest, 1980: 71, Fig. 26, pl. XII, Fig. 2; Zea, 1987: 114, Fig. 33, pl. IX, Fig. 2; Lehnert, 1993: 46, Fig. 71–73; Lehnert & Van Soest, 1998: 92.

Further synonymy: see Wiedenmayer (1977),Van Soest (1980) and Zea (1987).

Examined material. MCNPOR 5340, 72 m, 00°22’N – 44°52’W, 18.VII.2001; MCNPOR 5003, 94 m, 00°35’12”S – 43°20’55”W, 14/VI/1999 (fragment deposited in ZMAPOR 17915).

Material studied for comparison. Xestospongia subtriangularis (Duchassaing, 1850) ZMAPOR 9995 St. John, Virgin Isl. (fragment deposited in MCNPOR 2601).

Description. Thick ramose fragments (Fig. 9 A). Dimensions of bigger fragment (MCNPOR 5003): 7.5 cm long, 2.0 cm width, 2.8 cm height. Smooth surface. Oscules conspicuous, 0.15–0.6 cm in diameter. Preserved material with hard consistency, violet colour on the surface and light brown in the inner part.

Skeleton. Ectosome uni­ to multispicular network, with triangular to polygonal meshes 80–280 µm in diameter (Fig. 9 B), tracts 10–90 µm thickness. Choanosome with radial channels 200–440 µm in diameter (Fig. 9 C); multispicular primary ascending tracts (up to 15 spicules) 40–60 µm in diameter, with uni to plurispicular secondary interconnecting tracts, 20–70 µm thickness, rectangular and triangular meshes 80–250 µm in diameter.

Spicules. Oxeas (Figs. 9 D). slightly curved, with acerate ends, blunt to conical, simple or stepped. Mesurements: 60– 156. 7 –230 / 2.5– 3. 3 –6.3 µm (MCNPOR 5340); 73.6– 150. 6 –200 / 3.5– 4. 8 –6.9 µm (MCNPOR 5003).

Remarks. With our new record for the Brazilian coast, this appears to be another widespread species in the West Atlantic. The measurements of the oxeas are closely related to N. p roxima; however, the ascending primary tracts in the choanosome are unlike N. proxima skeletal features.

Distribution. West Atlantic: Florida to Colombia (Van Soest, 1980; Zea, 1987; Lehnert, 1993). Brazilian coast: Maranhão State (present study).