Phoriospongia mozambiquensis Calcinai & Belfiore & Pica & Torsani & Palma & Cerrano 2020, sp. nov.

Phoriospongia mozambiquensis Calcinai & Belfiore sp. nov.

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Fig. 19, Table 3

A red species of Phoriospongia characterized by styles with stepped tips, C and S-shaped sigmas, and isochelae.

The specific name is derived from type locality.

Holotype

PONTA DO OURO • fragment about 2× 2× 2 cm; 26°49′50.408″ S, 32°53′45.97″ E; Doodle; 17 m deep; 7 Feb. 2017; Cerrano leg.; MSNG 61420.

The live sponge (Fig. 19A) is irregularly massive, bright red and covered by algal turf. The fragment preserved in alcohol changed the color to grey, with an uneven surface. It is very hard and friable and rich in sediments.

SKELETON. The ectosome and the choanosome are almost completely constituted by columns of grains, with scattered spicules among the foreign bodies.

SPICULES. Styles (Fig. 19 B–C) with stepped tips, 260–(294.5, 24.2)–340 μm×2.5–(2.8, 0.8)–5 μm; C- and S-shaped sigmas (Fig 19D), 28–(37.2)–42 μm; arcuate isochelae (Fig. 19E), 9–(12.5)–14 μm.

This sponge belongs to the genus Phoriospongia, which is characterized by “skeletal columns cored by styles and foreign material [...]; sigmas usually present” (Van Soest 2002).

The genus Phoriospongia Marshall, 1880 includes 13 species, all with an Indo-Pacific Ocean distribution, mainly from Australia (Van Soest et al. 2019). Due to the nature of the skeleton and to the capacity of the sponge to incorporate foreign bodies, it is difficult to clearly detect the skeleton organization, and most of the original descriptions are inadequate (Table 3). Phoriospongia arenifibrosa (Dendy, 1896) differs from this new species due to the absence of megascleres and to the morphology (erect, palmo-digitate sponge). Phoriospongia argentea (Marshall, 1880) has shorter styles (80 μm) and does not have any microscleres. Phoriospongia canaliculata Lendenfeld, 1889 has oxeas instead of styles. Phoriospongia reticulum (Marshall, 1880) and P. solida Marshall, 1880 differ in the possession of tylostyles. Phoriospongia flabellopalmata (Carter, 1885) shows a smooth and even surface, with longer styles and raphides as microscleres. Phoriospongia carcinophila (Lendenfeld, 1889), P. levis Lendenfeld, 1888, P. mammillata (Lendenfeld, 1888) and P. syringiana (Whitelegge, 1906) have different megascleres, i.e., strongyles instead of styles. The description of P. papillosa (Lamarck, 1815) is inadequate and neither megascleres nor microscleres are reported. Phoriospongia poni (De Laubenfeld, 1950), described from the Hawaii Islands, has three kinds of megascleres, i.e., oxeas, strongyles and styles. In the original description, P. squalida Lendenfeld, 1888, spicules are not described and, moreover, the sponge is reported as erect and tubular.

Considering the affinities between Phoriospongia and Chondropsis, the species of the latter genus have been used for a comparison, but none was found to fit the new species from Mozambique (Table 2).