Radiospongilla inesi, Nicacio, Gilberto, Severi, William & Pinheiro, Ulisses, 2011

Nicacio, Gilberto, Severi, William & Pinheiro, Ulisses, 2011, New species of Radiospongilla (Porifera: Spongillidae) from Brazilian inland waters, Zootaxa 3132, pp. 56-63 : 58-62

Radiospongilla inesi sp. nov. Nicacio & Pinheiro

(Figs 1–4)

Holotype. UFPEPOR935. Recife, Parque Estadual Dois Irmãos, Riacho do Prata, Pernambuco State, Brazil, 8°1'9.40"S, 34°56'39.93"W, coll. Nicacio, G. 29/X/2009.

Type locality. Brazil, Northeast Region, Eastern North Atlantic Basin, Pernambuco.

Paratypes. Recife, Parque Estadual Dois Irmãos, Riacho do Prata, Pernambuco State, Brazil, 8°1'9.40"S, 34°56'39.93"W. 20/V/2007 coll. Severi, W. UFPEPOR674; 11/XII/2009 coll. Pinheiro, U.S. UFPEPOR940; 16/ XII/2009 coll. Nicacio, G. UFPEPOR944; 16/XII/2009 coll. Nicacio G., MNRJ 14746; 11/I/2010 coll. Nicacio, G., UFPEPOR948; 11/I/2010 coll. Nicacio, G., UFPEPOR949; 11/I/2010 coll. Nicacio, G., UFPEPOR950; 06/IV/2010 coll. Nicacio, G., UFPEPOR1091; 06/IV/2010 coll. Nicacio, G., UFPEPOR1092; 06/IV/2010 coll. Nicacio, G., UFPEPOR1093.

Additional material. Recife, Parque Estadual Dois Irmãos, Riacho do Prata, Pernambuco State, Brazil, 8°1'9.40"S, 34°56'39.93"W. 23/X/2009 coll. Pinheiro, U.S. UFPEPOR932; 23/X/2009 coll. Pinheiro, U.S. UFPEPOR934; 11/XII/2009 coll. Pinheiro, U.S. UFPEPOR936; 11/XII/2009 coll. Pinheiro, U.S. UFPEPOR937; 11/XII/2009 coll. Pinheiro, U.S. UFPEPOR938; 11/XII/2009 coll. Pinheiro, U.S. UFPEPOR939; 16/XII/2009 coll. Nicacio, G. UFPEPOR942; 16/XII/2009 coll. Nicacio, G. UFPEPOR946; 16/XII/2009 coll. Nicacio, G. UFPEPOR947; 11/I/2010 coll. Nicacio, G., UFPEPOR952; 11/I/2010 coll. Nicacio, G., UFPEPOR953; 11/I/2010 coll. Nicacio, G., UFPEPOR954; 11/I/2010 coll. Nicacio, G., UFPEPOR955; 11/I/2010 coll. Nicacio, G., UFPEPOR956; 11/I/2010 coll. Nicacio, G., UFPEPOR957; 11/I/2010 coll. Nicacio, G., UFPEPOR958; 11/I/2010 coll. Nicacio, G., UFPEPOR959; 06/IV/2010 coll. Nicacio, G., UFPEPOR1094.

FIGURE 1. Map of the geographic distribution and of the type locality of Radiospongilla inesi sp. nov. from Recife, Pernambuco State (in detail), Brazil (8°1'9.40"S, 34°56'39.93"W)

FIGURE 2. Radiospongilla inesi sp. nov. in situ from Recife, Pernambuco State, Brazil (8°1'9.40"S, 34°56'39.93"W).

FIGURE 3. Radiospongilla inesi sp. nov. from Recife, Pernambuco State, Brazil (8°1'9.40"S, 34°56'39.93"W) Holotype UFPEPOR935 (Coleção de Porifera da Universidade Federal de Pernambuco) SEM illustration of spicules and gemmule: a) Megasclere oxea b) Detail of the center of megasclere oxea c–d) Gemmosclere acanthostrongyle e) Gemmule f) Detail of the surface of the gemmule g) Detail of the gemmoscleres radially embedded.

Other material examined. Holotype of Radiospongilla amazonensis Volkmer-Ribeiro & Maciel, 1983 ( MNRJ 0088).

Diagnosis. Radiospongilla with megascleres oxeas microspined at middle of the axis or rarely smooth (15%), microscleres absent, gemmoscleres acanthostrongyles strongly spined (n=47–55–68), with straight and sharply pointed spines uniformly distributed along the axis, terminal spines with curved tips toward to the middle of axis, without formation of pseudorotules.

Description of holotype. UFPEPOR935 is encrusting, about 7 cm in diameter and 2 cm thickness, with one large and conspicuous osculum. Color is yellowish in vivo and light-brown after fixed in ethanol. Surface hispid. Megascleres oxeas slightly curved, microspined at the middle of the axis or rarely smooth (240–271.68–312/9– 11.1–15 µm), microscleres absent, gemmoscleres acanthostrongyles (66–70.74–78/3–3.68–4 µm).

Description. Sponge ranging from volcano-shaped, encrusting or massive, with a large conspicuous osculum and/or scattered small oscula (Fig. 2a–c). It has a maximum thickness of 3 cm and 40 cm of diameter. Color yellowish in vivo and light-brown after fixed in ethanol. Body is soft to very fragile. Surface hispid. Anisotropic skeleton with multispicular bundles connected by abundant spongin. Megascleres oxeas (228–260–288/9–12 µm) fusiform, straight or slightly curved, microspined at the middle of axis or rarely (15%) smooth (Fig. 3a; Fig. 4a–d). Microscleres absent. Gemmules abundant, yellowish, spherical, free, scattered or clustered at the base of sponge (300–338–384 µm). Foramen tubular single and without a collar. Gemmular theca tri-layered with gemmoscleres radially embedded. Outer layer with protruding distal apices of the gemmoscleres. Pneumatic layer well developed network of irregular spongin fibers. Inner layer of sublayered compact spongin (Fig. 3e–g). Gemmoscleres acanthostrongyles (51–69–78/3–3.2–4 µm) straight, strongly spined (n=47–55–68), radially embedded in gemmules (Fig. 3c–g; Fig. 4e–g). The spines of gemmoscleres along the axis are straight and sharp, uniformly distributed, however the terminal spines have curved tips toward the middle of axis. The spines along the axis are larger than the spines of the extremities and do not form pseudorotules. Free gemmoscleres can also be found in the symplasm, identical to those embedded in gemmules.

FIGURE 4. Radiospongilla inesi sp. nov. from Recife, Pernambuco State, Brazil (8°1'9.40"S, 34°56'39.93"W) Light microscopy illustration of megascleres and gemmoscleres: a–b) Smooth oxea megascrele (UFPEPOR 944 and UFPEPOR 1091, respectively) c–d) Spiny oxea megasclere (UFPEPOR 959) e–g) Gemmosclere acanthostrongyle (UFPEPOR 944, UFPEPOR 959 and UFPEPOR 1091, respectvely).

Ecology. The specimens were collected on the concrete substrate in perennial shallow waters environments, ponds and streams, depth ranging from 5 cm to 2 m, located at Parque Estadual Dois Irmãos, an urban remnant of Atlantic Forest. The area has approximately 387.4 ha, with undulating topography and altitudes ranging from 10 to 100 m. The climate is Tropical wet and dry ( As), following The Köppen Climate Classification for coastal regions of Northeastern Brazil. This region is hot and humid, with annual medium precipitation 2,460 mm and monthly average temperatures above 23° C ( Machado et al., 1998). Within the specimens were found Chironomids associated to sponges.

Etymology. The species is dedicated to Dr. Inês Ezcurra de Drago, for her great contribution to the knowledge of freshwater sponges from South America.

Remarks. Radiospongilla inesi sp. nov. is allocated to Radiospongilla on the basis of its anisotropic multispicular choanosomal skeleton, gemmoscleres as acanthostrongyles radially embedded on the gemmules and the lack of microscleres. The specimens studied here exhibit morphological differences from the other South American species that justify the proposal of a new species. Compared with Radiospongilla amazonensis , which has megascleres as thicker oxeas and strongyles, this new species has only one category of megasclere which is on average also thinner than those of R. amazonensis ( Table 1). The ends of oxea megascleres of R. amazonesis are slightly rounded and abruptly pointed (and hence listed as strongyles in Table 1), in contrast to those of R. inesi sp. nov. which are fusiform, sharply pointed oxeas (Fig. 3a; Fig. 4a–d). Moreover, R. amazonensis has gemmoscleres strongly spined at the extremities while in R. inesi sp. nov. the spines are uniformly distributed along the axis and also more abundant ( Table 1).

Radiospongilla crateriformis is the most similar species of Radiospongilla to the new species. Although that species possesses microspined oxea megascleres, it does not present smooth megascleres like R. inesi sp. nov. The main difference between these two species is the morphology of gemmoscleres. Radiospongilla . crateriformis displays curved spines and which are more concentrated at the extremities, giving appearance of pseudorotules, these gemmoscleres do not show a developed rotule but a group of curved hooks radiating from the apices of the shaft ( Potts, 1887, Plate X, Fig.V; Bass & Volkmer-Ribeiro, 1998, Fig. 2–3). However, R. inesi sp. nov. has spined extremities curved only at the tips and the spines along the axis are uniformly distributed and in greater number, as well the middle spines are larger than the extremities spines (Fig. 3c–e, 4e–g).