Discodermia proliferans Lévi F Lévi, 1983

Schlacher-Hoenlinger, Monika A., Pisera, Andrzej & Hooper, John N. A., 2005, Deep-sea “ lithistid ” assemblages from the Norfolk Ridge (New Caledonia), with description of seven new species and a new genus (Porifera, Demospongiae), Zoosystema 27 (4), pp. 649-698 : 681-686

Discodermia proliferans Lévi F Lévi, 1983

( Figs 4A ; 17 ; 31 )

Discodermia proliferans Lévi F Lévi, 1983: 121 , fig. VI, 4, pl. VII, 1-2, 4-9.

HOLOTYPE. — New Caledonian Slope ( MNHN DCL 2781 ).

MATERIAL EXAMINED (see Table 1). — Épon ge, 508-541 m ( QM G318557). — Introuvable, 575-589 m ( QM G318639). — Stylaster, 469-860 m ( QM G318697).

DESCRIPTION

Growth form

Arborescent, digitate sponges. The examined specimens are approximately 4 cm high.

Colour

Light beige in etoh.

Oscules

Not visible.

Texture

Hard, stony.

Surface ornamentation

Smooth with surface striation (subdermal canals).

Ectosomal skeleton

Ectosomal skeleton consists of a dense crust of round to oval discotriaenes with slightly incised margins and with short conical rhabds.

Choanosomal skeleton

Choanosomal skeleton consists of a dense skeleton of regular massive tetraclone desmas which bear strong, round and smooth tubercles. Desmas connected by strong zygoses. Acanthoxeas scattered throughout the choanosome.

Megascleres

Tetraclone desmas are thick, and strongly tuberculated, with very regular rounded and smooth tubercles: 500-600 µm/80-90 µm.

Discotriaenes: 492-673 µm.

Microscleres

Microacanthoxeas (centrotylote): 83.7-117 × 5.6-6.85 µm.

Acanthorhabds or strongyles (ovoid): 9.53-13.9 × 4.8-5.84 µm.

REMARKS

This new material is identical to the holotype in morphology and desma geometry, differing only in the larger diameter of discotriaenes, and in having larger microxeas.

Figures

FIG. 4. — A, Discodermia proliferans Lévi & Lévi, 1983; B, Homophymia pollubrum n. sp.; C, Reidispongia tuberculata n. sp.; D, R. coerulea Lévi & Lévi, 1988. Scale bars: 1 cm.

FIG. 17. — Discodermia proliferans Lévi & Lévi, 1983; A, B, outer surface with ectosomal discotriaenes; C, outer surface of the choanosomal skeleton; D, E, details of the outer surface of the choanosomal skeleton of tetraclone desmas; F, details of articulation between choanosomal desmas. Scale bars: A, D, 500 µm; B, F, 200 µm; C, E, 1 mm.

FIG. 31. — Discodermia proliferans Lévi & Lévi, 1983; A, microacanthoxeas; B, detail of microacanthoxeas; C, fusiform acanthorhabds; D, discotriaene. Scale bars: A, 20 µm; B, 5 µm; C, 2 µm; D, 200 µm.