Borojevia tenuispinata, Klautau, 2017

Klautau, Michelle, 2017, Taxonomy and phylogeny of calcareous sponges (Porifera: Calcarea: Calcinea) from Brazilian mid-shelf and oceanic islands, Zootaxa 4311 (3), pp. 301-344 : 311-313

Borojevia tenuispinata sp. nov.

( Figs 3 A–G; Table 4)

Diagnosis. Borojevia with triactines, tetractines, tripods and tetrapods. The apical actines of the tetractines and tetrapods have several (five or more) rows of radially disposed spines.

Material examined (Three specimens, all from São Pedro e São Paulo Archipelago, Brazil): Holotype: UFRJPOR 6484, Cabeço da Tartaruga, 8–12 m depth, coll. G. Rodríguez and F. Azevedo, 16 June 2011 ; Paratypes: UFRJPOR 6492, Cabeço da Tartaruga , 8–12 m depth, coll. G. Rodríguez and F. Azevedo, 16 June 2011 . UFRJPOR 8542, Cabeço da Tartaruga , 8–17 m depth, coll. G. Rodríguez and F. Azevedo, 17 June 2011 . MNRJ 8543 , Belmonte Island west cliff, 30 m depth, coll. F. Moraes, 15 July 2004 .

Etymology. From the Latin tenuis (= thin) and spinatus (= spined), for the presence of very thin spines on the apical actine of the tetractines.

Colour. white in life and in ethanol.

Morphology. Consistency fragile and friable. Cormus massive, formed by thin, regular and tightly anastomosed tubes ( Fig 3 A). The specimens were fragmented, therefore it was not possible to determine accurately the absence of water-collecting tubes.

Anatomy. No cells with granules were found. The skeleton is composed of triactines, tetractines, tripods and tetrapods, which look like large triactines and tetractines, respectively ( Fig 3 B). Triactines and tetractines occur in approximately the same proportion, or tetractines are a little more abundant. Tetrapods are less abundant than tripods

Spicules ( Figure 3 ; Table 4). Triactines: Equiangular and equiradiate. Actines are conical and straight, with tips varying from sharp to blunt ( Fig 3 C).

Tetractines: Equiangular and equiradiate. Actines are conical and straight, with tips sharp to blunt ( Fig 3 D). The apical actine has spines organized in several (five or more) rows radially disposed. They are very abundant, long and thin ( Fig 3 E).

Tripods: Equiangular and equiradiate or subregular. They look like large triactines with conical, stout actines and blunt tips ( Fig 3 F).

Tetrapods: Equiangular and equiradiate or subregular. They look like large tetractines with conical, stout actines and blunt tips ( Fig 3 G). The apical actine has spines similar to those of the tetractines.

Ecology. Specimens were found from 8 to 30 m of depth. Some specimens were associated with other sponges and algae.

Distribution. São Pedro e São Paulo Archipelago, off NE Brazil.

Remarks. we are naming tripods and tetrapods the large triactines and tetractines with stout actines that are located on the external tubes. As shown by Klautau et al. (2016), the shape of tripods varies even inside individuals, from characteristic ones with stout actines and raised centre to just large triactines. Those authors assigned this variability to polymorphism or plasticity. As we have already observed several times this variability in individuals of Borojevia , we agree with them and decided to name tripods and tetrapods the large triactines and tetractines present on the external tubes of B. tenuispinata sp. nov.. Because of the special position of these spicules in the cormus of Borojevia species, we think they are a different spicule category, not homologous to the triactines and tetractines found inside it.

Six species of Borojevia are currently recognised: B. aspina ( Klautau, Solé-Cava & Borojevic, 1994) , B. brasiliensis ( Solé-Cava et al., 1991) , B. cerebrum ( Haeckel, 1872) , B. croatica Klautau et al., 2016 , B. paracerebrum ( Austin, 1996) , and B. tetrapodifera ( Klautau & Valentine, 2003) . Only B. tetrapodifera and B. tenuispinata sp. nov. have tetrapods, however, differently from B. tetrapodifera the new species does not have many tetrapods. Besides, the apical actine of the tetrapods has spines while in B. tetrapodifera it is smooth.

Specimen Spicule Length (µm) Width (µm) n

min mean sd max min mean sd max

UFRJPOR 6484 (H) Triactine 59.4 65.3 4.9 75.6 5.4 7.2 0.7 8.1 30 Tetractine 51.3 65.3 5.9 78.3 5.4 7.7 0.8 8.1 24 Apical 27.0 40.0 8.6 56.7 4.1 4.9 0.8 6.8 20 Tripod 56.7 80.9 11.9 102.6 8.1 10.1 1.4 12.2 30 Tetrapod 64.8 72.9 5.9 81.0 9.5 10.4 0.7 10.8 0 6 Apical 21.6 28.4 9.5 35.1 4.1 4.7 1.0 5.4 0 2

UFRJPOR 6492 (P) Triactine 43.2 56.3 6.4 67.5 5.4 6.4 0.8 8.1 30 Tetractine 43.2 56.0 5.5 75.6 5.4 6.3 0.8 8.1 30 Apical 27.0 36.4 5.5 48.6 2.7 4.1 0.5 5.4 15 Tripod 48.6 65.5 8.8 81.0 6.8 8.5 0.8 9.5 30 Tetrapod 48.6 62.2 8.2 78.3 6.8 8.1 0.6 9.5 30 Apical 13.5 22.1 8.4 32.4 4.1 5.1 0.6 5.4 0 5

UFRJPOR 8542 (P) Triactine 40.5 56.0 5.8 64.8 4.1 6.0 1.0 8.1 30 Tetractine 48.6 60.5 6.7 81.1 5.4 6.8 0.8 8.1 30 Apical 27.0 40.8 7.8 50.4 4.1 4.3 0.5 5.4 20 Tripod 51.3 70.8 10.1 94.5 6.8 9.0 1.1 10.8 30 Tetrapod 48.6 68.1 9.5 89.1 8.1 8.7 0.9 10.8 30 Apical 13.5 20.5 7.8 32.4 4.1 4.9 0.7 5.4 0 5

Figures

FIGURE 3. Borojevia tenuispinata sp. nov. A—Holotype after fixation. B—Section. C—Triactine. D—Tetractine. E— Tetractine (ap: apical actine with spines). F—Tripod. G—Tetrapod.