Corvospongilla seckti Bonetto and Ezcurra de Drago, 1966

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 : 2374-2381

Corvospongilla seckti Bonetto and Ezcurra de Drago, 1966

( Figures 1–5 , Table 1)

New synonymy

Corvospongilla novaeterrae Potts, 1886 ; sensu Carvalho (1969, p. 126) – New synonymy. Non Potts (1886).

Corvospongilla volkmeri De Rosa Barbosa (1988, p. 111) – New synonymy.

For additional synonymy refer to Muricy et al. (2011).

Material studied

Brazil, East Atlantic Basin, Bahia: Manuel Vitorino Municipality, Rio de Contas, Barragem da Pedra , 13 ◦ 50 ′ 43.9 ′′ S, 40 ◦ 39 ′ 26.7 ′′ W, depth. 0.5 m, 1 February 2006, MNRJ 9306 , V. Castro leg. ; São Francisco Basin, Bahia State: Barra Municipality, Rio Grande , 11 ◦ 7 ′ 12.70 ′′ S, 43 ◦ 12 ′ 36.31 ′′ W, UFPEPOR 668 , W. Severi leg. 2008; eastern North Atlantic Basin, Pernambuco State: Jaqueira Municipality, Rio Pirangi , 08 ◦ 44 ′ 53.0 ′′ S, 35 ◦ 48 ′ 51.1 ′′ W, 12 December 2009, UFPEPOR 977 , G. Nicacio, leg. ; 13 June 2012, UFPEPOR 1364 , UFPEPOR 1365 , U. Pinheiro, leg. ; eastern North Atlantic Basin, Paraíba State: Marizópolis Municipality (formerly Souza ), Lagoa Redonda approx. 06 ◦ 47 ′ 58 ′′ S, 038 ◦ 19 ′ 43 ′′ W, 30 December 1961, MNRJ 0090 (holotype of C. volkmeri ), J.C. Mello de Carvalho leg.

Comparative material. Brazil, Paraná Basin, São Paulo State: Itapura Municipality, Rio Tietê , approx. 20 ◦ 21 ′ S, 51 ◦ 32 ′ W, 30 August 1998, depth. 8 m, MNRJ 1867 (in part), R.A. Franco, leg. ; 18 December 1999, depth. 4 m, MNRJ 2964 , U. Pinheiro, leg. ; Paraguay River Basin, Mato Grosso State: Santana do Livramento Municipality, Fazenda Experimental da Empaer , approx. 15 ◦ 52 ′ S, 56 ◦ 22 ′ W, 3 March 2004, MNRJ 9294 , E. V. Silva-Neto, leg.

Diagnosis

Corvospongilla with microspined strongyles as megascleres, acanthoxeas and acanthostrongyles as gemmoscleres.

Description

General morphology. Encrusting, friable consistency. Colour when alive between white ( Figure 1C ) and graphite grey. White sponges become yellowish when dry, and grey sponges retain their original colour ( Figure 1A ). Specimen UFPEPOR 1365 was green in some parts when alive, probably due to association with algae ( Figure 1D ). Specimen MNRJ 9306 is a thin crust (2 mm thick) measuring 168 cm 2, covering the major part of a formerly submerged twig ( Figure 1A ). UFPEPOR 668 also a thin crust (3–5 mm thick), growing over rock. Ectosomal skeleton an isodictyal reticulation, unispicular or paucispicular, with only scanty spongin.

Spicules. Megascleres predominantly microspined strongyles (over 90%, Figures 2A , 3A ), with variable degree of curvature and rare microspined mucronated strongyles ( Figures 2B,C , 3B,D ). Small recurved spines at surface, when near the tips, whereas those of median portion orthogonal to main axis. Gemmoscleres microspined strongyles ( Figures 2D,E , 3G ) and acanthoxeas ( Figure 3F ), both slightly curved. Microscleres pseudo-birotules ( Figures 2F , 3E ) with four to seven radial hooks on each rotule. Rotules flat or concave depending upon curvature of their hooks. The smooth shaft is isodiametric, straight or curved.

Gemmules averaging 450 µm in diameter, hemispherical, abundant, in two types, sessile and free. Foramen simple with short tube. Gemmules differ in morphology and position throughout the sponge. Sessile gemmules single or grouped, found adhering to substratum at sponge basal area. They are enveloped by gemmular cage made in part of gemmoscleres and megascleres, but stay loose inside ( Figure 2G ). Cage spicules are slightly bent microspined strongyles resembling skeletal megascleres. Short strongyle and acanthoxea gemmoscleres also occur in cage. Gemmular theca made by thin (24–48 µm) layer consisting of spongin, where short strongyles are embedded tangentially. Free gemmules scattered singly in the sponge skeleton, without spicular cage. They have a thick well-developed pneumatic layer (50–80 µm) formed by spongin in an alveolated arrangement. Microspined strongyles and acanthoxea gemmoscleres radially and tangentially embedded. Colour grey or yellowish.

Ecology

Sponges were encrusting a submerged twig in a water reservoir and submerged rocks along the margins of a river in a low hydrodynamic environment. The water was very turbid but some light appeared to be reaching the specimens.

Distribution

Argentina and Brazil. Brazilian Hydrographic Basins: Amazon, Tocantins – Araguaia, Paraguay, Paraná, eastern North Atlantic, East Atlantic, São Francisco, Uruguay and South Atlantic. Brazilian States: Pará, Tocantins, Paraíba, Bahia, Goiás, Mato Grosso, Mato Grosso do Sul, Minas Gerais, São Paulo, Paraná, Pernambuco, Rio Grande do Sul ( Figure 5 ). See the references for each of these records in Muricy et al. (2011).

Remarks

The species is widely distributed in Brazil, known now from nine out of twelve hydrographic basins (all Brazilian basins according to ANA). It has not been found yet in the western North Atlantic, Parnaiba and southeast Atlantic basins. Despite this wide distribution, only minor morphological differences were detected in sponges from distantly located regions. For instance, MNRJ 9306 was graphite coloured, as found by Bonetto and Ezcurra de Drago (1966) and Volkmer-Ribeiro and Parolin (2010). In the rest of the material studied here, as well as in the remaining redescriptions, specimens have always been yellowish when alive. Considerably thicker specimens were described from Paraíba (when proposing C. volkmeri, De RosaBarbosa 1988 ) and Rio Grande do Sul (figs 4.1 and 4.8 in Volkmer-Ribeiro and Parolin 2010). The present study is the first record of this species from the east Atlantic and São Francisco basins.

Characterization of the holotype

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 3. Corvospongilla seckti Bonetto and Ezcurra de Drago, 1966 (UFPEPOR 977), spicular components: (A) microspined strongyle megasclere; (B) microspined mucronated strongyle megasclere; (C, D) details in the tip of the microspined mucronated strongyle and microspined strongyle megascleres, respectively; (E) pseudobirotule microsclere; (F) acanthoxea gemmosclere; (G) acanthostrongyle gemmosclere; (H) gemmule; (I) transversely cut gemmule; (J) detail of the gemmule foramen. Scale bars in A, B = 25 µm; C–G = 10 µm; H–J = 100 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.

Figure 5. Map of distributions of Corvospongilla seckti Bonetto and Ezcurra de Drago, 1966 with all records (Muricy et al. 2011 and present work).