Calthropella Calthropella simplex Sollas, 1888

Van Soest, Rob W. M., Beglinger, Elly J. & De Voogd, Nicole J., 2010, Skeletons in confusion: a review of astrophorid sponges with (dicho-) calthrops as structural megascleres (Porifera, Demospongiae, Astrophorida), ZooKeys 68, pp. 1-88 : 46-48

Calthropella Calthropella simplex Sollas, 1888

Calthropella simplex Sollas 1888: 107, pl. X figs 13-14, 21-29; Topsent 1892: 42, pl. VII fig. 9.

Material examined.

None. Type material could not be found in the Natural History Museum (query in 2009).

Description

(from Sollas 1888 and Topsent 1892). Massive, with irregular upper surface, in places with tuberculate oscules; pale yellow to grey. Size up to 9 ×4.5× 3.8 cm ( Sollas’ type). Ectosomal cover of globular asters. Choanosome cavernous, but densely spiculated with a mass of calthrops.

Spicules: calthrops, globular spherasters and ‘normal’ oxyspherasters.

Calthrops, of widely different sizes, according to Sollas divisible into larger (cladi dimensions 800 × 90 µm) and smaller (150 × 20 µm).

Spheroxyasters, considered a young stage of the tuberculated asters by Sollas, but identified as a proper separate aster-type by Topsent; no size given by either authors but according to Topsent the same size as the truncated asters, so 12-24 µm in diameter.

Globular spherasters with tuberculated rays, variable, often irregular, in a wide size range, possibly divisible in two size categories, 24 µm and 12 µm.

Habitat.

Deep water, on gravel/sand bottom. Sollas provides no depth data, Topsent’s material came from 454 -861 m.

Distribution.

Cape Verde Islands (off Porto Praya, Santiago Island), Azores (38-39°N 30°W).

Remarks.

This species differs from the closely similar Calthropella (Calthropella) geodioides in the lack of dichocalthrops (but these are small and rare in Calthropella (Calthropella) geodioides ) and oxeas (but these are an unstable complement not certainly proper in Calthropella (Calthropella) geodioides ). Apart from Sollas (1888) and Topsent (1904) (who expressed doubts whether Calthropella simplex and Calthropella geodioides might be synonyms), no records of this species have been published. It is also closely similar to a new species from Indonesia, Calthropella (Calthropella) xavierae sp. n. (see below). Topsent (1892) distinguished a variety ‘durissima’ for specimens with globular spherasters becoming entirely irregularly rounded in some specimens; these specimens are here assigned to a separate species of Calthropella (Calthropella) (see below).