Borojevia crystallina sp. nov.

(Figure 4, Table 4)

Diagnosis. Borojevia whose tripods are at least 140 µm long and 20 µm thick.

Etymology. From the Latin crystallinus (= of crystal) for the spines of the apical actines that resemble crystals.

Type Locality. Le Rocher du Diamant, Martinique.

Type Material. (One specimen) Holotype: UFRJPOR 7937, Le Rocher du Diamant, Martinique (1426.556' N–612.408' W), collected by B. Cóndor-Luján, 15 May 2011, 12 m depth.

Colour. Light pink in ethanol, however, this colour is probably due to a Demospongiae that was fixed in the same jar.

Description. Cormus massive, hispid, not compressible, composed of regular and tightly anastomosed tubes (Figure 4A). No cells with granules were found. The aquiferous system is asconoid. No water-collecting tubes were observed, but the analysed specimen was very small, hence it was not possible to be sure about their absence.

Skeleton. The skeleton has no special organisation (Figure 4B), and it is formed by triactines, which are more abundant than the other categories, tetractines with spines on the apical actine and tripods, which are usually located only on the external tubes.

......continued on the next page *From Klautau et al. (1994). **From Klautau & Valentine (2003). ***From Klautau et al. (2016). ****From Austin (1996). *****From Azevedo et al. (2017).

Spicules (Table 4)

Tripod: Regular (equiangular and equiradiate). Actines are conical with blunt tips. They are similar to large triactines, without the characteristic elevated centre (Figure 4C). Size: 140.0–195.0/20.0–27.5 µm.

Triactine: Regular or subregular. Actines are conical to slightly conical with blunt tips (Figure 4D). Size: 70.0–100.0/10.0–15.0 µm

Tetractine: The basal actines are similar to those of the triactines (Figure 4E). Size: 65.0–95.0/10.0–12.5 µm. The apical actine has spines in several rows covering almost all its extension (Figure 4F–G). Size: 22.5–32.5/3.7– 6.2 µm.

Ecology. The specimen was collected attached to a rock with other incrusting animals, such as other calcareous sponges, a Demospongiae and a Bryozoa. The specimen was collected in a semi-dark cave.

Remarks. Eight 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), B. tenuispinata Azevedo et al., 2017, B. trispinata Azevedo et al., 2017, and B. tetrapodifera (Klautau & Valentine, 2003). Borojevia crystallina sp. nov. can be differentiated from all of them mainly by the size of the tripods, which are much larger and thicker in this new species (169.2/21.9 µm vs. 115.0/ 11.8 µm in B. paracerebrum, which is the second species with the largest tripods, Table 3). Five out of nine species of Borojevia occur in the Tropical Western Atlantic (B. aspina, B. brasiliensis, B. tenuispinata, B. trispinata, and B. crystallina sp. nov.) and the new species is the second record of Borojevia for the Caribbean Sea. In the ITS molecular tree (Figure 16), B. crystallina sp. nov. is more related to B. croatica, with 56% bootstrap and p-distance of 1.7%. In the analysis of the C-LSU region (Figure 17), where a different set of species was used, the new species did not group with any other species of the genus.

Geographical distribution. Le Rocher du Diamant, Martinique.