Ascoleucetta sagittata Cavalcanti, Rapp & Klautau, 2013

Van Soest, Rob W. M. & De Voogd, Nicole J., 2015, Calcareous sponges of Indonesia, Zootaxa 3951 (1), pp. 1-105 : 49

Ascoleucetta sagittata Cavalcanti, Rapp & Klautau, 2013

Figures 36a–f

Ascoleucetta sagittata Cavalcanti et al., 2013: 308 , Figs 21–22 .

Material examined. Holotype ZMA Por. 13283, Indonesia, SW Sulawesi, Spermonde Archipelago, Kudingareng Keke , depth 15 m, SCUBA, coll. N.J. de Voogd, #KK/NV/130497/32, 13 April 1997.

Description. The holotype description is here summarized from Cavalcanti et al. 2013: Yellow massive sponge ( Figs 36a–c ) presumably consisting of a tight mass of tubes, but this is largely obscured. In stead there are some folded portions and lacunae in the interior ( Fig. 36d ), which indicate the tubes. Presumably the aquiferous system is solenoid, but this is not elaborated. The skeleton contains three categories of triactines, one large regular ( Fig. 36e ), 300–550 x 20–55 µm, one small sagittal ( Fig. 36g ) with unpaired actines 85–144 x 5–10 µm and paired actines 80–150 x 5–10 µm, one small regular ( Fig. 36f ), 110–160 x 12–15 µm, and small regular tetractines ( Fig. 36h ) with actines of the basal radiate system 110–150 x 10–12.5 µm and apical actines ( Fig. 36h 1 ) 37–65 x 5–7.5 µm. The latter are protruding into the lumen of the internal tubes.

Ecology. Shallow-water reefs.

Distribution. Indonesia.

Remarks. This species was recently described from a fragment, and we provide here images of the whole specimen. The presence of sagittal triactines is not observed very frequently, and they are not associated with the oscules, since there are no proper oscules in the holotype specimen. This species was earlier confused with specimens assigned to Leucetta chagosensis because of similarity in spiculation with it (see below). By careful comparison, we have become convinced that Ascoleucetta sagittata and the yellow globular-massive Leucetta -like specimens, which are so commonly encountered in the shallow reefs of Indonesia and the adjacent regions, are virtually indistinguishable and may very well be the same species. From molecular sequence results of Voigt et al. (2012) there are indications that L. chagosensis is not closely related to other Leucetta species like Leucetta microraphis Haeckel, 1872 , which might support the idea that L. chagosensis is an Ascoleucetta , not a genuine Leucetta , conspecific or very closely related to A. sagittata . This would require careful histological sections. We refrain from making a definite conclusion on this species because of a forthcoming revision of Klautau et al. on Leucetta .

Figures

FIGURE 1. Map of Indonesia and adjacent countries showing approximate distribution of the sample location. Each white square represents one or more localities, and one or more specimens. Detailed locality positions are provided in the material examined data with each species (Free Edition map courtesy www.primap.com)

FIGURE 21. Ernstia naturalis sp. nov., a, holotype RMNH Por. 9342, images of the spicules, a, triactine, b–c, tetractines, d, detail of apical actine of tetractine.

FIGURE 22. Burtonulla sibogae Borojevic & Boury-Esnault (1986), a, in situ image of RMNH Por. 1653 from the Palau Islands (photo N.J. de Voogd), b, preserved holotype ZMA Por. 00146 (scale bar = 1 cm), c, in situ image of RMNH 1821 from Maratua Island (photo B.W. Hoeksema).

FIGURE 36. Ascoleucetta sagittata Cavalcanti et al. (2013), holotype ZMA Por. 13283, a–c, various images of preserved holotype, showing surface and atrium (scale in a = 1 cm), d cross section of skeleton, showing layered structure (scale bar = 500 µm), c–f, SEM images of the spicules, e, large triactines of the surface, f, small triactine, e, sagittal triactine, f, tetractine, f1, detail of tetractine.