Borojevia brasiliensis (Solé-Cava, Klautau, Boury-Esnault, Borojević & Thorpe, 1991)

(Fig 7; Table 4)

Synonyms: Clathrina cerebrum, sensu Borojević 1971: 526 [non Clathrina cerebrum (Haeckel, 1872)]. Clathrina brasiliensis, Solé-Cava et al. 1991: 382; Klautau et al. 1994: 372; Klautau & Borojević 2001: 403; Klautau & Valentine 2003: 11. Borojevia brasiliensis, Klautau et al. 2013: 458.

Material examined: UFRJPOR 8827, Escalvada Island, 12 m depth, 31.iii.2017, colls. A. Padua and C. Leal.

Diagnosis: White Borojevia with regular and tightly anastomosed tubes. Skeleton composed of tripods, triactines and tetractines, always conical. Spines on the apical actine of tetractines are very thin at the base, being proportionally much thinner than longer. They are organised in 3–6 rows.

Description: Cormus formed by thin, regular and tightly anastomosed tubes. Water-collecting tubes converge to large oscula. Colour white alive and in ethanol (Figs 7A, B). Consistency soft and slightly compressible. Surface of the tubes smooth. Aquiferous system asconoid.

Skeleton composed of tripods, triactines and tetractines (Fig 7C). Triactines are the most abundant spicules.

Spicules (Figs 7D–F; Table 4).

Tripods: Regular to subregular. Actines conical, undulated and stout, with blunt tips (Fig 7D). Size: 98.9 (± 9.1)/ 13.1 (± 1.1) µm (N = 20).

Triactines: Regular. Actines conical and straight, with blunt to sharp tips (Fig 8E). Size: 71.1 (± 9.3)/ 9.0 (± 1.3) µm (N = 30).

Tetractines: Basal actines are similar to the triactines (Fig 7F). The apical actine is shorter than the basal ones, conical, straight, sharp and ornamented with spines proportionally much thinner than longer and organised in 3–6 rows (Fig 7G). Size: basal actine—73.8 (± 12.7)/ 9.4 (± 2.0) µm (N = 20); apical actine—46.8 (± 4.5)/ 5.1 (± 0.3) µm (N = 20).

*From Klautau and Valentine (2003).

Ecology: The only specimen was collected among other sponges, hydrozoans and algae (Fig 7A).

Distribution: Eastern Brazil ecoregion—Guarapari, Espírito Santo State (present study); Cape of São Tomé, Rio de Janeiro State (Borojević 1971). Southeastern Brazil ecoregion—Arraial do Cabo (Enseada), Rio de Janeiro State (type locality; Solé-Cava et al. 1991).

Taxonomic remarks: The first report of Borojevia brasiliensis was to Cape of São Tomé, Rio de Janeiro State, Brazil by Borojević (1971) as Clathrina cerebrum (now Borojevia cerebrum; see Klautau et al. 2013). Borojevia cerebrum was originally described from the Mediterranean Sea (Haeckel 1872), and allozymes and molecular analyses indicated that the populations from Brazil were not conspecific with those from the Mediterranean (Solé-Cava et al. 1991). For that reason, the Brazilian specimens were named B. brasiliensis. Before this study, B. brasiliensis was considered endemic to Rio de Janeiro State (Muricy et al. 1991), hence we are here extending its distribution northwards to Espírito Santo State, which means to another ecoregion, the Eastern Brazil ecoregion.

Some morphological variations were observed when comparing the specimens from Espírito Santo with the holotype from Rio de Janeiro. The tips of the triactines and tetractines are mostly blunt in the holotype and sharp in our specimen. However, spicules with sharp tips were also found in the holotype. The C-LSU and ITS trees recovered the specimens of B. brasiliensis from Rio de Janeiro and Espírito Santo in a single clade highly to moderately supported (C-LSU: B = 100%, PP = 0.9; ITS: B = 78%, PP = 0.7) and p-distances were of 0.0% for both markers.