Amphilectus strepsichelifer, Van Soest, Beglinger, Vooged, 2012

Van Soest, Rob W. M., Beglinger, Elly J. & de Voogd, Nicole J., 2012, Sponges of the family Esperiopsidae (Demospongiae, Poecilosclerida) from Northwest Africa, with the descriptions of four new species, European Journal of Taxonomy 18, pp. 1-21 : 7-9

Amphilectus strepsichelifer sp. nov.

Fig. 4

Etymology

The name is a combination of strepsis (L.) = twisted, and chelifer (L.) = bearing chelae, reflecting the twisted condition of the chelae.

Material examined

Holotype

ZMA Por. 07564 , Cape Verde Islands, W of São Vicente, Canal de São Vicente, depth 348-354 m, coll. R. W.M. Van Soest, CANCAP 7 Expedition stat. 172/03, 16.8833°N 25.1167°W, rectangular dredge, 7 Sep. 1986.

Description

Pedunculate sponge ( Fig. 4A ), with long thin smooth stalk and abruptly attached small ovate main body. Main body flattened, but solid (not hollow). Upper surface somewhat rectangular, caused by preparation damage. Surface irregular, shaggy. Colour light brown alive, grey in alcohol. Size of main body 12 x 6 mm, stalk 35 mm long, 1.2 mm thick.

SKELETON. Of main body plumose, rather than plumoreticulate, with diffuse spicule bundles directed at right angles to the surface ( Fig. 4B ), where they form loose brushes. Connecting spicules few and arranged irregularly. Chelae in loose groups in a subectosomal layer at the base of the surface brushes ( Fig. 4C ). Few chelae in the interior.

SPICULES. ( Fig. 4 D-E) Styles, palmate isochelae.

STYLES. ( Fig. 4D, D 1 ) Thin, slightly curved, 396- 430.5 -462 x 3- 4.6 - 7 µm.

PALMATE ISOCHELAE. ( Fig. 4E ) Predominantly with ‘twisted’ shaft, causing the alae of opposite ends to face different angles, a minority of the chelae appearing ‘normal’ but these are of the same size as the twisted ones, and upon closer examination appear to be slightly twisted as well, 32- 33.7 - 36 µm.

Distribution and ecology

Known only from the type locality between the islands of São Vicente and Santo Antão, Cape Verde Islands ( Fig. 1 , loc. 4), hard bottom, at depths below 300 m.

Remarks

The species is assigned to Amphilectus on the same basis as A. utriculus sp. nov. The species stands out among stalked Amphilectus species (see above in the remarks on A. utriculus sp. nov.) by the peculiar twisted condition of the palmate isochelae. Additionally the thin stalk carrying the main body without a clear intermediate zone is characteristic and not found in the other North Atlantic Amphilectus species.

Figures

Fig. 4. Amphilectus strepsichelifer sp. nov., Holotype ZMA Por. 07564. A. Habit. B-C. Cross section of skeleton in light microscopy. B. Peripheral skeleton. C. Detail of peripheral tracts and clustered microscleres. D-E. SEM images of spicules. D. Style. D1. Details of apices. E. Palmate isochelae, in various stages of torsion.

Fig. 1. Map of Northwest Africa, showing the approximate localities from which the sponges were collected. 1. Mauritania, Cap Blanc. 2. Mauritania, Banc d’Arguin. 3. Mauritania, SW of Cap Timiris 4. Cape Verde Islands, São Vicente 5. Cape Verde Islands, Ilheu de Cima.