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

Fontana, Tayara, Cóndor-Luján, Báslavi, Azevedo, Fernanda, Pérez, Thierry & Klautau, Michelle, 2018, Diversity and distribution patterns of Calcareous sponges (subclass Calcinea) from Martinique, Zootaxa 4410 (2), pp. 331-369 : 350-351

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

( Figure 9 , Table 9)

Synonyms. Clathrina sp. nov. 2: Pérez et al. 2017: 13. Clathrina mutabilis: Azevedo et al. 2017: 307 , Cóndor-Luján et al. 2018: 23.

Material Examined. (14 specimens) UFRJPOR 7866, Le Rocher du Diamant , Martinique (14°26.556' N – 61°2.408' W), collected by B. Cóndor-Luján , 16 May 2015, 14 m depth. UFRJPOR 7836, UFRJPOR 7837, UFRJPOR 7838, UFRJPOR 7839, Anse Noire, Anses d'Arlet , Martinique (14°32.024' N – 61°05.278' W), collected by B. Cóndor-Luján , 14 May 2015, 11 m depth. UFRJPOR 7660, Le Rocher du Diamant , Martinique (14°26.556' N – 61°2.408' W), collected by F. Azevedo , 25 April 2015, 18.8 m depth. UFRJPOR 7847, Jardin de Salomon, Anses d'Arlet, Martinique (14°30'21.5'' N – 61°05'35.7'' W), collected by B. Cóndor-Luján, 0 5 May 2015, 13 m depth. UFRJPOR 7876, Anse de Fortune , Anse d'Arlet , Martinique (14°30.377' N – 61°05.850' W), collected by B. Cóndor-Luján , 16 May 2015, 6 m depth. UFRJPOR 7426, Pointe Burgos, Anses d'Arlet , Martinique (14°29.787' N – 61°5.351' W), collected by B. Cóndor-Luján and P. Chevaldonné, 0 6 December 2013 . UFRJPOR 7436, UFRJPOR 7441, Pointe Burgos, Anses d'Arlet, Martinique (14°29.787' N – 61°5.351' W), collected by M. Klautau, 0 3 December 2013, 11 m depth. UFRJPOR 7432, Pointe Burgos , Anses d'Arlet , Martinique (14°29.787' N – 61°5.351' W), collected by M.Klautau and T. Pérez, 0 4 December 2013 . UFRJPOR 7413, UFRJPOR 7420, 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 light beige in ethanol.

Description. Cormus formed by large, irregular and loosely anastomosed tubes ( Figure 9A–B ). Cells with granules were not present. Water-collecting tubes are not present and the oscula are simple openings spread throughout the apical region. Aquiferous system asconoid.

Skeleton. The skeleton is disorganised ( Figure 9C ) and composed of two categories of triactines.

Spicules ( Table 9).

*From Azevedo et al. (2017).

Triactine I: Regular. Actines are conical with sharp tips ( Figure 9D ). Size: 45.0–100.0/7.5–10.0 µm.

Triactine II: Regular, subregular or parasagittal. Actines are cylindrical with blunt tips ( Figures 9E, F, G ). Size: 120.0–170.0/7.5–10.0 µm (regular and subregular). Unpaired actine: 100.0–215.0/7.5–10.0 µm, paired actines: 50.0–135.0/7.5–10.0 µm (parasagittal).

Trichoxeas: Straight, very thin and frequently broken:>140.0–215.0/2.5 µm.

Ecology. This species was found in environments protected from light, such as the entrance of tunnels, underneath rocks and in crevices. One of the specimens (UFRJPOR 7866) was attached to a Demospongiae of the genus Myrmekioderma .

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

Remarks. Clathrina mutabilis closely resembles C. insularis but these two species can be distinguished by the triactine I, which is more rare and thicker in the former ( Table 9). Besides, the phylogenetic tree showed that both species are molecularly very distant ( Figure 15 ).

Comparing the specimens of C. mutabilis from Martinique with those from Brazil and Curaçao, we found a very well supported clade (bootstrap of 100%) with a p-distance varying from 0% to 0.2% ( Figure 15 ). However, a morphological difference was found. In the specimens from Martinique, triactines II are not only regular and subregular but also parasagittal. This was previously observed in the specimens from Curaçao ( Cóndor-Luján et al. 2018). As parasagittal spicules are always present in specific regions, such as peduncle or external tubes, and in the present species they are scattered, we consider that it is only a variation of the triactine II and the presence of this spicule only in the specimens from the Caribbean Sea is polymorphism. Another polymorphism we found was in the presence of trichoxeas. The specimens from Curaçao have not presented trichoxeas, while only some specimens from Brazil did. In Martinique, 11 of 14 specimens had trichoxeas. As already discussed by Azevedo et al. (2017), the presence of trichoxeas in this species is polymorphic.

Figures

FIGURE 9. Clathrina mutabilis (UFRJPOR 7866). A. Specimen in situ (UFRJPOR 7836). B. Specimen in ethanol. C. Tangential section. D. Triactine I. E. Triactine II (regular). F. Triactine II (subregular).G. Triactine II (parasagittal).

FIGURE 15. Detail of the maximum likelihood tree of the ITS nuclear marker for the genus Clathrina. The Bootstrap values are shown in the branches.The sequences generated in the present study are marked with an asterisk.