Strongylacidon meganese (de Laubenfels, 1951 )

Calcinai, Barbara, Bavestrello, Giorgio, Bertolino, Marco, Pica, Daniela, Wagner, Daniel & Cerrano, Carlo, 2013, Sponges associated with octocorals in the Indo-Pacific, with the description of four new species, Zootaxa 3617 (1), pp. 1-61 : 14-15

Strongylacidon meganese (de Laubenfels, 1951)

( Fig. 7 A–F)

Examined material. Sample Carramba 8 sp. 3: Indonesia, Ambon Island, Depan Tupa, depth not stated, 2008.

Description. The sponge encrusts a Carijoa riisei ( Fig. 7 A) colony partially covering the polyp calyces ( Fig. 7 B). The sample occurs on two branches of the coral, up to 14 cm long. The thickness of the sponge is about 0.5 mm, the surface is smooth, pale yellow in ethanol preserved specimens ( Fig. 7 B).

Skeleton. No specialized ectosomal skeleton; the main skeleton is a confused arrangement with strongyles organized in tracts without clear orientation and numerous scattered microscleres ( Fig. 7 C).

Spicules. Strongyles straight and thin ( Fig. 7 D), 135 – (189.8 ± 29.6) – 225 x 1.2 – (2.3 ± 0.6) – 3.7 μm. Isochelae ( Fig. 7 E), 12.5 – (14.9 ± 1.8) – 18.7 μm, frequently with a cutting on the frontal ala.

Distribution and remarks. This is a new record for Indonesia and the second record of the species since its original description from Hawai’i. Our specimen fits with the original description of de Laubenfels (1951) who reported this species as a paper-thin incrustation with strongyles of 210 – 240 x 3 µm and chelae 16 µm long. The species is the only Strongylacidon from the Indo-Pacific area, characterised by arcuate chelae (not unguiferate), by the lack of sigmas and by a single category of strongyles.

Figures

FIGURE 7. Strongylacidon meganese (de Laubenfels, 1951). A, Sponge encrusting Carijoa riisei; B, Close up showing polyps free from sponge covering; C, Skeleton composed of strongyles organized in tracts without clear orientation; D, Strongyle with close up of the tips; E, Isochelae.