Dercitus Stoeba verdensis, Van Soest, Rob W. M., Beglinger, Elly J. & De Voogd, Nicole J., 2010

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 : 22

Dercitus Stoeba verdensis sp. n. Figs 10 A–D

Dercitus plicatus ; Van Soest 1993: Table 2, pars (not: Dercitus plicatus sensu Schmidt 1868).

Material examined.

Holotype ZMA Por. 07521b, Cape Verde Islands, São Nicolau, Branco, 16.6667°N; 24.7167°W, dredged from 98 m, coll. R.W.M. Van Soest, HMS ‘Tydemann’ CANCAP VII Expedition stat. 156, 5 September 1986.

Description

(Fig. 10A). Encrusting sponge, agglutinating and consolidating limestone fragments (dead corallines and serpulids), pale yellow-coloured, with cartilaginous consistency. Growing together with a yellow-coloured Chaetodoryx sp. Size of agglutinated mass approx. 4 × 2 cm.

Skeleton: a confused mass of dichocalthrops with a thin crust of sanidasters.

Spicules: dichocalthrops (no calthrops), sanidasters.

Dichocalthrops (Fig. 10B) relatively large, regularly shaped, with limited size variation, protocladi more or less uniform in smaller and larger spicules, but deuterocladi longer in larger ones: protocladi 42 –48.2– 56 × 9 –21.6– 35 µm, deuterocladi 23 –106.8– 204 × 4 –17.2– 29 µm, rhabdomes 71 –170.6– 252 × 8 –21.0– 31 µm, cladomes 132 –294.6– 475 µm.

Sanidasters relatively small, little variation in spination and ornamentation, 11 –13.3– 16 µm.

Etymology.

Named after the type locality.

Habitat.

Deeper water, consolidating coarse sediment.

Distribution.

So far with certainty known only from the type locality. Possibly, Topsent’s 1928 record of Dercitus plicatus from Boavista also belongs to this species.

Remarks.

Although the specimen was originally identified with Dercitus plicatus , there are two compelling differences with that species: (1) there are no calthrops, whereas these are the dominant spicule in Dercitus (Stoeba) plicatus , and (2) the size of the dichocalthrops, especially the length of the deuterocladi, is up to twice that of Dercitus (Stoeba) plicatus .