Clathrina fakaravae, Klautau & Lopes & Guarabyra & Folcher & Ekins & Debitus, 2020

Klautau, Michelle, Lopes, Matheus Vieira, Guarabyra, Bruna, Folcher, Eric, Ekins, Merrick & Debitus, Cécile, 2020, Calcareous sponges from the French Polynesia (Porifera: Calcarea), Zootaxa 4748 (2), pp. 261-295 : 269-270

Clathrina fakaravae sp. nov.

( Fig 3 , Table 3 )

Etymology. From the type locality (Fakarava)

Type locality. Maruka (Fakarava). Tuheiava (Tikehau). Avatoru (Rangiroa) Tuamotu Islands. French Polynesia .

Material examined. Holotype: UFRJPOR 6884 = MNHN-IP- 2018-49 — Rangiroa , Tuamotu Islands, station TRAN05 (14°56.481’ S– 147°51.752’ W), depth: 24 m, coll. E. Folcher, 23/V/2011, P322 . Paratype: UFRJPOR 6873 = MNHN-IP- 2018-38 — Fakarava , Tuamotu Islands, Station TFAK08 (16°08.230’ S– 145°49.323’ W), depth: 15 m, coll. A. Renaud, 19/ V /2011, P305˗ TFAK08 . Other material: UFRJPOR 6875 = MNHN-IP- 2018-40 — Tikehau , Tuamotu Islands, station TTIK03 (14°59.629’ S– 148°16.922’ W), depth: 40 m, coll. E. Folcher , 29/ V /2011 , P305˗ TTIK03 .

Diagnosis. White Clathrina with large and loosely anastomosed tubes, no water-collecting tubes and three categories of triactines: conical, slightly conical and cylindrical.

Colour. White alive and beige to light yellow in ethanol ( Fig 3A ).

Morphology and anatomy. The cormus of this species is formed by large, irregular and loosely anastomosed tubes but in some regions the anastomosis is very tight, giving an appearance of a continuous membrane. Watercollecting tubes were not observed. Aquiferous system asconoid. The skeleton is composed of two categories of triactines, one cylindrical to slightly conical (the most abundant) and the other conical ( Fig 3B ).

Spicules ( Table 3 )

Triactines I. Regular (equiangular and equiradiate). Actines are cylindrical to slightly conical with sharp tips ( Fig 3E ). Size: 95.7/ 7.2 µm.

Triactines II. Regular (equiangular and equiradiate). These spicules are larger. Actines are conical with sharp tips ( Fig 3D ). Size: 159.8/ 12.3 µm.

Geographical distribution. Rangiroa, Tuamotu Islands; Fakarava, Tuamotu Islands; Tikehau, Tuamotu Islands.

Remarks. Although the tight anastomosis of the tubes in some parts of the cormus gives the impression of a begining of a continuous membrane formation, there is no cavity (pseudoatrium), therefore, it could not be an Ascaltis . As it seems to us that there is no true continuous membrane, we consider we have a true Clathrina , perhaps with a beginning of cortex formation (cortical membrane). Unfortunately, for this species we were not able to get DNA sequence.

Clathrina fakaravae sp. nov. has two categories of triactines (cylindrical to slightly conical and conical) and white cormus formed by irregular and loosely anastomosed tubes without water-collecting tubes, hence, we compared it with: C. rotundata Voigt et al., 2017 and C. zelinhae Azevedo et al., 2017 . Clathrina rotundata , however, has also parasagittal triactines and actines with rounded tips, while the new species has always regular spicules with sharp tips. Clathrina zelinhae has tightly anastomosed tubes and the difference between the size of its conical and cylindrical spicules is much larger than in C. fakaravae sp. nov. [ C. fakaravae sp. nov. —Triactines with cylindrical actines: 95.7 (±7.2)/ 7.2 (±1.5) µm; Triactines with conical actines: 159.8 (±13.2)/ 12.3 (±1.4) µm; C. zelinhae (holotype)—Triactines with cylindrical actines: 95.8 (±5.4)/ 3.9 (±1.0) µm; Triactines with conical actines: 271.1 (±13.2)/ 20.8 (±2.2) µm]. Therefore, our specimens constitute a new species for science.

Figures

FIGURE 3. Clathrina fakaravae sp. nov. (UFRJPOR 6884). A—Fixed specimen. B—Section. C—Triactines I. D—Triactine II.