Clathrina insularis Azevedo, Padua, Moraes, Rossi, Muricy & Klautau, 2017

(Figure 8, Table 8)

Synonyms. Clathrina sp. nov. 1: Pérez et al. 2017: 13. Clathrina insularis: Azevedo et al. 2017: 307, Cóndor-Luján et al. 2018: 19.

Material Examined. (One specimen) UFRJPOR 7428, Pointe Burgos, Anses d'Arlet, Martinique (14°29.787' N – 61°5.351' W), collected by M. Klautau and T. Pérez, 0 6 December 2013.

Colour. Yellow alive and brown in ethanol.

Description. Cormus composed of irregular and loosely anastomosed tubes (Figure 8A). Surface smooth and texture soft. Water-collecting tubes are not present. No cells with granules were found. Aquiferous system asconoid.

Skeleton. The skeleton is disorganised (Figure 8B) and composed of two categories of triactines. Spicules (Table 8).

*From Azevedo et al. (2017).

Triactines I: Regular. Actines are conical with sharp tips (Figures 8D–E). They are very rare. They are the smallest triactines of this species. Size: 35.0–82.5/6.2–7.5 µm.

Triactines II: Regular or subregular. Actines are cylindrical to slightly conical, distally undulated and with sharp tips (Figures 8C–F). They are the most abundant spicules. Size: 100.0–120.0/7.5–10.0 µm.

Ecology. The specimen was collected in a crevice, protected from sunlight.

Remarks. Azevedo et al. (2017) commented that the yellow clathrinas that most resemble morphologically C. insularis are C. luteoculcitella Wörheide & Hooper, 1999 and C. chrysea Borojevic & Klautau, 2000, as they have sharp actines. However, they can be differentiated by the anastomosis of the cormus, which is tight in C. luteoculcitella and C. chrysea, and loose in C. insularis .

Comparing the specimen from Martinique with the holotype from Brazil, we found a small variation in the size of the spicules, with the individuals from Martinique having slightly smaller spicules (Table 8). In our phylogenetic tree the specimens from Martinique grouped with those from Brazil and Curaçao with 100% bootstrap and the pdistance varied from 0% to 0.5% (Figure 15).

Geographical distribution. Fernando de Noronha Archipelago, off NE Brazil (Azevedo et al. 2017) , Curaçao (Cóndor-Luján et al. 2018), and Martinique.