Pericharax orientalis Van Soest & De Voogd, 2015

Van, Rob W. M. & De, Nicole J., 2018, Calcareous sponges of the Western Indian Ocean and Red Sea, Zootaxa 4426 (1), pp. 1-160 : 87-89

Pericharax orientalis Van Soest & De Voogd, 2015

Figs 51a–h

Pericharax heteroraphis ; sensu Dendy 1913: 13 (not: Pericharax carteri var. heteroraphis Poléjaeff, 1883: 66 ).

Pericharax orientalis Van Soest & De Voogd, 2015: 57 , figs 41a–e, 42a–e.

Material examined. RMNH Por. 10157, Maldives, Faafu Atoll, Wallstreet, 3.119°N 72.979556°E, depth 12 m, scuba, coll. N.J. de Voogd, field nr . MAD10/MAS118, 20 February 2015; ZMA Por. 17996, Mauritius, 20.0304°S 57.5364°E, depth 7–28 m, scuba, coll. P. Daniel Marie, field nr. MO4SP5TB, 2014 ; ZMA Por. 18308, Mauritius, 20.0378°S 57.5361°E, depth 10–20 m, scuba, coll. P. Daniel Marie, field nr. 5, December 2014 ; ZMA Por. 21792, Mauritius, depth 10–20 m, scuba, coll. P. Daniel Marie, field nr. VI sp.17, December 2010 .

Description. Since this species was treated extensively recently (see Van Soest & De Voogd, 2015), we provide here only a short description. Large, yellow-green, upright or volcanoe-shaped sponges ( Fig. 51a ), with faintly ridged or shallowly grooved sides and prominent wide central vent or oscule. Occasionally two or more individuals are attached forming a small group. Sizes up to 10 cm or more in height, 10 cm or more in diameter. Surface may be covered in tiny tubes of syllid worms. In preservation, specimens become red-brown ( Fig. 51b ). Consistency hard, rough to the touch.

Aquiferous system. Leuconoid.

Skeleton. Cortical region with a thin layer of small sagittal triactines forming rounded subdermal spaces, carried by tangentially arranged subcortical giant triactines. Choanosomal skeleton built predominantly by small triactines supporting the leuconoid canal system. The atrial walls are formed predominantly by tetractines with their apical actines protruding into the atrial cavity ( Fig. 51c ).

Spicules. ( Figs 51d–h ) Giant triactines, small cortical triactines, small choanosomal triactines, atrial tetractines.

Giant triactines ( Fig. 51d ), equiradiate, equiangular, 396– 1386 –2310 x 28– 124.3 –222 µm.

Cortical triactines ( Fig. 51e ), irregular, slightly sagittal, with all three actines slightly different and somewhat wavy, 54– 88 –119 x 6 – 8.1 –11 µm.

Small triactines ( Fig. 51f ), regular, equiradiate, equiangular, 126– 181 –228 x 12 – 15.9 –23 µm.

Tetractines ( Figs 51g –h ), with basal radiate system equiradiate, equiangular, actines 106– 156 –192 x 7 – 11.3 –17 µm, apical actines ( Fig. 51h ) thin, mostly wavy or curved, but may be straight, 25– 67 –108 x 4 – 6.4 –10 µm.

Distribution and ecology. Maldives, Mauritius, elsewhere widely distributed in the Indo-West Pacific tropical region, on reefs down to 20 m or deeper.

Remarks. Pericharax peziza Dendy, 1913 is a small cup-shaped sponge, pale yellow in alcohol, which has not been found again after its original description from Cargados Carajos. Its skeletal architecture and spiculation is similar to P. orientalis .

We obtained sequences of the holotype of Pericharax orientalis from Indonesia (RMNH Por. 5259) and of the above described RMNH Por 10157 from the Maldives and in our phylogenetic analysis ( Fig. 2C ) both ended up in the same clade at moderate bootstrap value.

Recently, Leocorny et al. (2017) described several new Pericharax species from Western Australia, P. vallii Leocorny et al., 2017 , and P.crypta Leocorny et al., 2017 . These species clearly differ from the present specimens in aspects of habitus and spicule sizes. Leocorny et al. (2017) found that Leucetta and Pericharax could not be retrieved as monophyletic, and this is confirmed in our Fig. 2C .

Figures

FIGURE 2. Maximum-likelihood tree based on analysis of sequences of the partial 28S gene (C2–D2 region, comprising 442 sites) of Western Indian Ocean Calcinea newly generated by the Naturalis Biodiversity Center and sequences additionally obtained from GenBank, the Sponge Barcode Project and from Oliver Voigt (München) from the Red Sea, Indonesia, Australia, and a few sequences from other parts of the world, to demonstrate the affiliation of the compared species. Please note that Arturia sequences do not appear in the same clade, indicating Arturia is non-monophyletic. Numbers at the root of clades are bootstrap values of 1000 replicates. Since the high number of sequences were difficult to read in detail, we subdivided the present tree in three detailed sections 2A, 2B, and 2C.

FIGURE 51. Pericharax orientalis Van Soest & De Voogd, 2015, RMNH Por. 10157, from the Maldives, a, habitus in situ (photo N.J. de Voogd), b, on deck, c, cross section of atrial wall to show apical actines of the tetractines protruding in the atrial lumen, d–h, SEM images of the spicules, d, giant triactine, e, cortical triactine, f, small triactine, g, tetractine, h, detail of g showing thin apical actine.