Neopetrosia proxima (Duchassaing & Michelotti, 1864)

Figs. 8 A–D; Tab. IV

Thalysias proxima Duchassaing & Michelotti, 1864: 84, pl. VIII, Figs. 2–3.

Densa araminta De Laubenfels, 1934: 14; 1950: 168.

Xestospongia sp. Collette & Rützler, 1977: 309.

Xestospongia proxima; Van Soest et al., 1983: 198 –204; Zea, 1987: 116 –119, Fig. 34, pl. IX, Figs. 3–4; Van Soest & Stentoft, 1988: 132 –133, pl. XII Fig. 4, text­Fig. 64; Lehnert & Van Soest, 1996: 77 –78.

Examined material. MCNPOR 5334, 72 m, 00°22’N – 44°52’W, 17/VII/2001 (fragment deposited in ZMAPOR 17917); MCNPOR 5107, 93 m, 00°11’13”N – 44°46’12”W, 10/VI/ 1999; MCNPOR 5016, 5276, 00º20'38"S – 44º17'38"W, 85 m, 12/VI/1999; MCNPOR 3845, 72 m, 00°32’S – 43°50’W, 18/XI/1997; MCNPOR 4967, 4996, 5000, 94 m, 00°35’12”S – 43°20’55”W, 14/VI/1999; MCNPOR 4781, 31 m, 00°51’44”S – 44°21’24”W, 12/VI/1999; MCNPOR 3814, 3823, 80 m, 01°33’81”S – 43°15’87”W, 02/XII/1997 (MCN­ POR 3823: fragment deposited in ZMAPOR 17916); MCNPOR 3791, 72 m, 02°14’49”S – 42°00’20”W, 06/XII/1997.

Material studied for comparison. Xestospongia sp., off the mouth of Amazon river (re­examined). Deposited in MCNPOR 2468 (det. Klaus Rützler).

Description. Irregular, finger­like fragments (Fig. 8 A): 17 cm long, 2.8 cm large, up to 4 cm height (measurements of the bigger fragment MCN 3823). Surface punctiform, hispid to the touch, infested with Parazoanthus; only one oscule visible, 1 cm in diameter. Preserved material incompressible consistency, colour light brown.

Skeleton. Similar to descriptions of Zea (1987) and Lehnert & Van Soest (1996). Measurements emended. Ectosome: Uni­ to multispicular fibres, 30– 88. 8 –170 µm in diameter (Fig. 8 B); meshes 150– 243. 6 –360 µm in diameter. Choanosome: sub­superficial channel (Fig. 8 C), 70–304.9–700 µm thickness (N=45), multispicular primary fibres (60–200 µm thickness), fascicles 350–750 µm in diameter, secondary fibres 40–90 µm thickness, meshes 80–220 µm in diameter.

Spicules. Oxeas (Figs. 8 D): slightly curved, acerate or occasionally hastate. Measurements: 117.5– 147. 4 –172.5 / 2.5– 3. 2 –5 µm (MCNPOR 5334); 121.9– 147 –165.6 / 2.3– 4. 7 – 6.9 µm (MCNPOR 5107); 89.7– 132. 8 –161 / 2.3– 4. 8 –5.8 µm (MCNPOR 5016); 125– 169. 3 –190 / 2.5– 4. 7 –6.3 µm (MCNPOR 5276); 105–136–157.5 / 3.8– 4. 8 –5 µm (MCN­ POR 3845); 142.6– 153. 5 –163.3 / 3.5– 5. 2 –6.3 µm (MCNPOR 4967); 115– 133 –149.5 / 3.5– 5. 2 –6.9 µm (MCNPOR 4996); 131.1– 141. 4 –151.8 / 2.3– 4. 2 –4.6 µm (MCNPOR 5000); 117.3– 143. 1 –156.4 / 2.3– 4. 6 –5.8 µm (MCNPOR 4781); 115–145.5–182.5 / 1.3– 4.4–7.5 µm (MCNPOR 3814); 132.5–155.8–170 / 2.5–4.9–7.5 µm (MCNPOR 3823); 120– 154. 3 –197.5 / 2.5– 4. 2 –5 µm (MCNPOR 3791).

Remarks. Well­known species in the Caribbean region and adjacent areas; often it is characterized by its hard consistency and also by the presence of Parazoanthus on the surface; our samples do not possess a sticky surface, maybe due to substances released during preservation. According to Zea (in litt.), the samples studied here are very similar to the material that he studied, collected by Collette & Rützler (1977) and previously identified as Xestospongia sp. (now placed in the genus Neopetrosia).

Distribution. Caribbean: Puerto Rico to Colombia (Zea, 1987; Van Soest & Stentoft, 1988; Lehnert & Van Soest, 1996). Brazilian coast: off the mouth of Amazon River (Collette & Rützler, 1977); Maranhão State (present study).