Radiospongilla sp.

Manconi, R. & Pronzato, R., 2005, Freshwater sponges of the West Indies: Discovery of Spongillidae (Haplosclerida, Spongillina) from Cuba with biogeographic notes and a checklist for the Caribbean area, Journal of Natural History 39 (36), pp. 3235-3253 : 3247-3248

Radiospongilla sp.

( Figures 1 , 5 )

Material examined

Five small specimens labelled DTRGFW599, from the Laguna del Tesor , La Boca- Guama, Cienaga de Zapata, west Cuba, 15 December 2000, R. Manconi leg.

Description

Growth form from encrusting to small cushion. Colour whitish-greenish. Consistence fragile both in vivo and in dry conditions. Surface smooth. Oscules conspicuous, 2–3 mm in diameter, irregularly scattered. Ectosomal skeleton with tangential spicules in the dermal membrane, with few emerging tufts of two or three spicules. Choanosomal skeleton paucispicular with irregular meshes from alveolar to more or less triangular. Basal spongin plate well developed and spicular. Megascleres slightly bent oxeas (2842348×9.3214 Mm) smooth to rarely spiny except at the sharp tips ( Figure 5A ). Apices sometimes bent or with two to three tips. Microscleres (1122163×324.5 Mm) few to rare straight acanthoxeas with spines increasing in density towards the sharply pointed tips; apical spines ornate by microspinosities ( Figure 5B–D ). Gemmules absent.

Remarks

The absence of gemmules, probably due to the active life cycle phase of the sponges, renders it impossible to determine the taxon at the species level. Diagnostic skeletal traits of the sponge such as shape and size of the spicular complement suggest the ascription of specimens to a species of the genus Radiospongilla .

Habitat

Sponges were settled under limestone boulders in waters rich in carbonates of a lentic habitat along the northern edge of the Laguna del Tesor. The latter is the largest (900 hectares) natural and most pristine wetland of Cuba (maximum depth 10 m, mean ca 4 m) within the Gran Parque Natural de Montemar with large extension of swamps and coastal brackish lagoons .

Figures

Figure 1. Study area of freshwater sponges in western Cuba with sites of sampling (circles) and findings (black dots with numbers). Cueva de los Indios (1: 22°409N, 83°439W; 2: 22°409N, 83°439W), Embalse San Juan (3), Rio San Juan (4), rapids in Rio San Juan (5), Embalse El Jibaro (6: 22°319N, 83°419W), Embalse El Salto (7: 22°379N, 83°419W), two small embalses along the Pinar–La Habana road (8: 22°589N, 82°399W; 9: 23°019N, 82°319W), Giardino Botanico Nacional of La Habana (10: 22°589N, 82°239W), Rio Ariguanabo near San Antonio de los Baños (11: 22°559N, 82°289W), Laguna del Tesor (12: 22°249N, 81°089W).

Figure 5. Radiospongilla sp. from Cuba (DTRGFW599). SEM photomicrographs of spicular complement. (A) Megasclere oxeas with small spines; (B) spiny apices of microscleres; (C) microspined shaft of microsclere; (D) microsclere.