Hemiasterella complicata Topsent, 1919

Fig. 27

Hemiasterella complicata Topsent, 1919: 7, figs 2–5.

Material examined

PONTA DO OURO • 1 single, dried fragment of about 4 × 3 cm × 8 mm, several dried portions, 1 alcohol preserved; 26°46′39.864″ S, 32°55′25.284″ E; Cloud break; 34 m deep; 18 May 2015; Torsani leg.; IMG0516 • 1 fragment, alcohol preserved, of about 11 × 5 × 4 mm; 26°50′36.881″ S, 32°54′54.478″ E; Atlantis; 40.7 m deep; 6 Feb. 2017; Cerrano leg.; PO20 • 1 fragment, alcohol preserved; 26°46′38.829″ S, 32°54′17.387″ E; Waynes; 40.6 m deep; 17 Feb. 2017; Cerrano leg.; PO53 .

Description

The sponge is lamellate, foliose; color is dark red to violet (Fig. 27 A–B). On the surface, two specimens present algal turf. The samples preserved in alcohol changed color to beige; the dried samples are whitish, light brown; in the dried state, spicule tracts create an irregular pattern and thick lines on the surface. The samples have a micro-bristly surface and an elastic consistence.

SKELETON. The ectosome is constituted of a layer of densely packed euasters (Fig. 27C). the choanosome with plumo-reticulate tracts is formed by megascleres (Fig. 27D), without a well-marked differentiation between axial and extra-axial regions.

SPICULES. The megascleres are constituted by strongyloxeas and oxeas (Fig. 27E), with a wide range of intermediate forms, 590–(842.5, 100.8)– 980 µm ×10–(17.25, 4.3)– 25.5 µm; strongylasters with at least five rays (Fig. 27F) with microspined rays 7.5–(12.4, 3.6)– 20 µm, and smooth oxyasters 5–(8.9, 3.8)– 25 µm (Fig. 27G).

Remarks

The examined material fits with the species Hemiasterella complicata Topsent, 1919 . This is a species with a strict distribution, confined to East Africa and Madagascar (Burton 1959; Vacelet et al. 1976; Pulitzer-Finali 1993). This species is also similar to Hemiasterella vasiformis (Kirkpatrick, 1903) (Topsent 1919), recently recorded by Samaai et al. (2019) in South Africa; as a consequence, a revision of the genus Hemiasterella and a genetic analysis would be necessary in order to clarify the possible synonymy.