Chondrilla caribensis Rützler, Duran & Piantoni, 2007

(Figs. 8 A–F, 13D)

Synonymy: Chondrilla nucula Rützler, Duran & Piantoni:292; Gómez 2007:57.

Material examined. CNPGG –1271 Sisal Banks reefs (21º26’24”N 90º28’25.39”W), depth 7 m, 13/VI/2011. CNPGG –1447 Alacranes reef (22º22’59.7”N 89º40’46.6”W), depth 20 m, 06/VIII/2009.

Description. Encrusting to massive sponge 20–30 × 30–50 mm with 9 mm thick. Pale cream to green color when alive in specimen CNPGG–1271 (Fig. 13 D), fulvous in specimen CNPGG-1447, creamy with brown tinges in alcohol, and its surface is smooth and shiny. Oscules are scarce and measure 0.5–7 mm in diameter. The consistency is firm and elastic.

Skeleton. Characterized by a thin cortex 140–300 µm thick which is densely packed by spherasters (Fig. 8 B). Scattered spherasters are present in the choanosome, and their density increases along the aquiferous canals.

Spicules. Spherasters 5.7–30 µm in diameter, with variation in the ray tips. Their main trait are the smooth conical rays (Fig. 8 D, E), sometimes with blunt rays 10–28 µm in overall diameter, centrum size 5.7–15.6 µm, encompassing more than 50% of the total diameter, and ray length 2.1–7.2 µm. Spherasters with secondary smooth or microspined rays (Fig. 8 C, F) 5–30 µm in overall diameter. Few spheroxyasters are present with same size of the former with centrum diameter 8.6 µm (<50 % of total diameter) and ray length of 7.8 µm. The number of rays fluctuates in the two from 16–20. Quite a number of smooth silica drops were present, some with scattered spines (not measured).

Distribution and ecology. Florida Keys, Bimini, Belize, Bermuda, Virgin Islands, and Panama, on rock, conch shells, red mangrove stilt roots, peat banks, and seaweeds from shallow reef lagoon 0.2 to 4 m in depth (Rützler et al. 2007). Our specimens were found in open reef and encrusting a rock, at 7 m in depth. The present specimen is the first record for the species in the southern Gulf of Mexico.

Remarks. The present material completely agrees with the description of Chondrilla caribensis, the only difference between them is the spheraster size, which is slightly larger (12–37.5 µm) than in the present material. With respect to other Caribbean distribution of Chondrilla spp, those from C. nucula, a Mediterranean species, probably must be assigned to C. caribensis, which would extend its distribution.