Corvospongilla volkmeri De Rosa Barbosa, 1988

Pinheiro, Ulisses, Docio, Loyana, Nicacio, Gilberto & Hajdu, Eduardo, 2013, A reassessment of neotropical species of Corvospongilla (Porifera: Spongillidae), Journal of Natural History 47 (37 - 38), pp. 2373-2384 : 2381-2382

Corvospongilla volkmeri De Rosa Barbosa, 1988

( Figures 1E , 4A–I , Table 1)

Description

General morphology. Cushion-shaped ( Figure 1E ), 7 × 2.8 × 1 cm (length × width × thickness). Its colour is dark grey at the external surface and beige inside. There is no distinction between ectosome and choanosome. The skeleton is composed of delicate ascending spiculofibres, interconnected by orthogonal bundles, forming polygonal meshes.

Spicules. Megascleres, microspined strongyles ( Figures 4A , 2C ) or microspined mucronated strongyles ( Figures 4B,D ), straight or slightly curved, 120–160 µm long and 5–12 µm wide. Mucronated forms (predominant) very similar in dimensions and general morphology to blunt-ended strongyles (rare), differing only by possession of spine (mucron, spur) at tips of spicule ( Figures 4C,D ). Small spines at surface are recurved near tips, whereas those in middle portion are straight, perpendicular to the shaft. Gemmoscleres predominantly acanthoxeas ( Figure 4E ) 18–68 µm long and 8–14 µm wide. Microsclere pseudo-birotules ( Figure 4F ) 17–34 µm long and 2.5–4.5 µm wide, with at least four hooks for each rotule. Shaft smooth and isodiametric, straight or curved.

Gemmules small, hemispherical ( Figures 4G–I ), white, averaging 450 µm in diameter. Two types, sessile and free. Sessile gemmules single or grouped, and enveloped by a cage of megascleres and gemmoscleres, similar to features described for C. seckti (cf. above). Abundant free gemmules, single, with well-developed pneumatic layer bearing acanthoxeas tangentially embedded in gemmular theca ( Figure 4I ).

Ecology

The sponge has been described as occurring in great quantities in Lagoa Redonda, located in the Caatinga biome ( Carvalho 1969). Specimens were growing over a quince-wood fence standing in the water, substantially coating all the timber and also attached to the existing rocks at the margin and inside the pond.

Figures

Figure 1. Corvospongilla seckti Bonetto and Ezcurra de Drago, 1966: (A, B) specimen MNRJ 9306 encrusting on tree branch, arrow indicates the gemmules of sponge; (C, D) specimens UFPEPOR 1364 and UFPEPOR 1365 encrusting on rock, respectively; (E) holotype of Corvospongilla volkmeri De Rosa Barbosa, 1988 (MNRJ 0090). Scale bars = 1 cm.

Figure 2. Corvospongilla seckti Bonetto and Ezcurra de Drago, 1966 (MNRJ 9306), spicular components: (A) microspined strongyle megasclere; (B) microspined mucronated strongyle megasclere; (C) detail of the tip of the microspined mucronated strongyle megasclere; (D) acanthoxea gemmosclere; (E) acanthoestrongyle gemmosclere; (F) pseudobirotule microsclere; G) set of gemmules; (H, I) gemmule without gemmular capsule of gemmoscleres. Scale bars in A, B, G–I = 100 µm; C–F = 5 µm.

Figure 4. Holotype of Corvospongilla volkmeri De Rosa Barbosa, 1988 (MNRJ 0090), spicular components: (A) microspined strongyle megasclere; (B) microspined mucronated strongyle megasclere; (C, D) details in the tip of the microspined strongyle and microspined mucronated strongyle megascleres, respectively; (E) acanthoxea gemmosclere; (F) pseudobirotule microscleres; (G) gemmule; (H) transversely cut gemmule; (I) detail in the wall of gemmule. Scale bars A, B, E, F = 10 µm, G–I = 50 µm; C, D = 5 µm.