Leucetta chagosensis Dendy, 1913

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 : 279-281

Leucetta chagosensis Dendy, 1913

( Fig 8 , Table 8 )

Synonyms. Leucetta chagosensis —Dendy 1913: 10 , Dendy & Row 1913: 733, Dendy & Frederick 1924: 482, Burton 1963: 241, Borojević 1967: 2, Pulitzer-Finali 1982: 89, Gosliner et al. 1996: 16, Lévi et al. 1998: 77, Wörheide & Hooper 1999: 882, Borojević & Klautau 2000: 194, Wörheide et al. 2002: 1753, Wörheide et al. 2005: 379, Baine & Harasti, 2007: 15, Wörheide et al. 2008: 1, Voigt et al. 2012a: 101, Van Soest & De Voogd 2015: 51, 2018: 76; L. infrequens— Row & Hôzawa 1931: 747, Burton 1963: 241, Borojević & Klautau 2000: 195; L. expansa— Row & Hôzawa 1931: 749, Burton 1963: 241; Ascoleucetta sagittata Cavalcanti et al. 2013: 308 , Van Soest & De Voogd 2015: 49; Leucetta sp.— Colin & Arneson 1995: 60 (photo 230).

Material examined. UFRJPOR 6455 = MNHN-IP- 2018-26 — Moorea , Society Island, Station SM01 (17°29.681’ S– 149°51.717’ W), depth: 10 m, coll. C. Debitus , 04/XII/2010, P2- SM01 . UFRJPOR 6889 = MNHN-IP- 2018- 54 — Makemo , Tuamotu Islands, Station TMAK06 (16°28.120’ S– 143°57.200’ W), depth: 18 m, coll. B. Bourgeois , 10/ V /2011, P266. UFRJPOR 6871 = MNHN-IP- 2018-36 — Fakarava , Tuamotu Islands, Station TFAK04 (16°05.231’ S– 145°44.127’ W), depth: 50 m, coll. B. Bourgois , 18/ V /2011. UFRJPOR 6874 = MNHN-IP- 2018- 39 — Rangiroa , Tuamotu Islands, Station TRAN04 (15°05.314’ S– 147°56.531’W), depth: 30 m, coll. E. Folcher , 23/ V /2011. UFRJPOR 6876 = MNHN-IP- 2018-41 — Fakarava , Tuamotu Islands, Station TFAK02 (16°04.900’ S– 145°41.497’ W), depth: 15m, coll. S. Petek , 17/ V /2011. UFRJPOR 6878 = MNHN-IP- 2018-43 — Rangiroa , Tuamotu Islands, Station TRAN01 (15° 13.359° S– 147°14.832’ W), depth: 40 m, coll. B. Bourgeois , 22/ V /2011. UFRJPOR 6882 = MNHN-IP- 2018-47 — Toau , Tuamotu Islands, Station TTOA03 (15°47.480’ S– 145°55.120’ W), depth: 18 m, coll. A. Renaud , 21/ V /2011. UFRJPOR 6885 = MNHN-IP- 2018-50 — Tetiaroa , Society Islands, Station STET01 (17°02.258 S– 149°33.707 W), depth: 40 m, coll. A. Renaud , 31/ V /2011 , P266˗ STET01 . UFR- JPOR 8955 = MNHN-IP- 2018-64 — Makemo , Tuamotu Islands, Station TMAK11 (16°38.485’ S– 143°387.934’ W), depth: 30 m, coll. M. Dumas , 08/XI/2018, P669- TMAK11 . UFRJPOR 8956 = MNHN-IP- 2018-65 — Makemo , Tuamotu Islands, Station TMAK11 (16°38.485’ S– 143°38.934’ W), depth: 20 m, coll. S. Petek , 08/XI/2018, P670- TMAK11 . UFRJPOR 8958 = MNHN-IP- 2018-67 — Rangiroa , Tuamotu Islands, Station TRAN06 (14° 55.927° S– 147°43.329’ W), depth: 30 m coll. M. Dumas , 13/XI/2018, P669- TRAN06 . UFRJPOR 8959 = MNHN-IP- 2018-68 — Rangiroa , Tuamotu Islands, Station TRAN18 (14° 55.841° S– 147°44.019’ W), depth: 15 m, coll. M. Dumas , 11/XI/2018, P669- TRAN18 . UFRJPOR 8960 = MNHN-IP- 2018-69 — Rangiroa , Tuamotu Islands, Station TRAN18 (14° 55.841° S– 147°44.019’ W), depth: 15 m, coll. M. Dumas , 11/XI/2018, P670- TRAN18 . Comparative material. BMNH 1920.12 .9.51 (holotype) .

Colour. Yellow alive, beige in ethanol ( Fig 8A ).

Morphology and anatomy. Sponge massive, spherical to sub-spherical, covered by a smooth cortex. Apical osculum surrounded by membrane ( Fig 8A ). Hard and friable. There are subcortical inhalant cavities and the canals are disposed in parallel, giving a radial organisation to the choanosome. Large exhalant canals arrive into the atrium, giving it a reticulated appearance. Aquiferous system leuconoid. The skeleton is composed of giant triactines, present mainly on the cortex, and small triactines and tetractines ( Fig 8B ). The small triactines are present on the cortex and choanosome, while the small tetractines, which are few, are found only in the choanosome, mainly in the exhalant canals.

Spicules ( Table 8 )

Giant triactines. Regular. Actines are conical with sharp tips ( Fig 8E ). Variable sizes. Size: 523.0/ 40.0 µm.

Triactines. Regular to subregular. Actines are conical with sharp tips but some few spicules have cylindrical actines. The apical actine of the tetractines is conical and sharp ( Fig 8F, I ). Size: 139.1/ 13.6 µm.

Tetractines. Regular to subregular. They are very few. Actines are conical with sharp tips but some have cylindrical actines. The apical actine is conical, sharp, smooth and curve ( Fig 8G ). Size: 107.8/ 10.0 µm (basal actine); 32.0/ 5.2 µm (apical actine; Fig 8H ).

Geographical distribution. Indian Ocean—Chagos Archipelago (Dendy 1913), Abrolhos Islands ( Dendy & Frederick 1924), Red Sea and Maldives ( Wörheide et al. 2008, Voigt et al. 2012a); Western Pacific Ocean—Indo-nesia, Philippines, Japan, Western Australia, French Polynesia, and Samoa ( Wörheide & Hooper 1999, Wörheide et al. 2002, 2005, 2008, Voigt et al. 2012a), New Caledonia ( Borojević 1967, Lévi et al. 1998, Borojević & Klautau 2000).

Remarks. Leucetta chagosensis is a species originally described from Chagos Archipelago (Indian Ocean). Although in the original description Dendy (1913) had mentioned only the presence of large and small triactines, we found few tetractines in the holotype ( Table 8 ) and these spicules are being observed in all specimens identified as L. chagosensis .

This species is considered to be widespread in the Indo-Pacific where it is characterised by its bright yellow colour when alive, lobose habitus, large triactines and small triactines and tetractines, the latter being rare. It is possible that L. chagosensis represents a species complex ( Wörheide et al. 2002, 2005, 2008; Voigt et al. 2012a), however, as this putative species complex has not been solved yet, we call our specimens L. chagosensis .

Figures

FIGURE 8. Leucetta chagosensis (UFRJPOR 6455). A—Fixed specimen. B—Cross-section of the choanosome. The asterisk indicates the atrial skeleton. C—Tangential section of the cortex. D—Tangential section of the atrium. E—Giant triactine. F—Small triactines. G—Small tetractine. H—Apical actine of a tetractine.Abbreviation: cx = cortex.