Corallistes australis, Schlacher-Hoenlinger & Pisera & Hooper, 2005

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 : 663-664

Corallistes australis n. sp.

( Figs 2E ; 9 ; 23 )

HOLOTYPE. — Jumeau-West seamount, Norfolk Ridge, 23°40’33’’S, 168°00’43’’E, 237-250 m, RV Alis, 21.VI.2001, Warén dredge, coll. T. Schlacher ( MNHN DCL 3901 , a fragment of the holotype in QM [G318559s).

ETYMOLOGY. — Named for the southerly location of the study area ( australis, Latin for southern).

OTHER MATERIAL EXAMINED (see Table 1). — Banc 2, 267- 266 m (QM G318567); 200-291 m (QM G318698, QM G318702). — Jumeau-West, 237- 250 m (QM G318760); 234-261 m (QM G318776).

DESCRIPTION

Growth form

Wide cylindrical/massive club-shaped to cylindrical/spherical sponges with narrow axial cavity, extending half its height, and located at the opening of the conical sponge summit with a single osculum, which is closed in most specimens. Specimens all have closed oscula, are approximately 4 to 5 cm high and 2 to 3 cm wide, with a base approximately 3 cm broad.

Colour

Greyish white in etoh.

Oscules

Not visible.

Texture

Hard, stony.

Surface ornamentation

Optically smooth.

Ectosomal skeleton

Ectosomal skeleton contains smooth dichotriaenes and abundant amphiasters/streptasters with blunt rays.

Choanosomal skeleton

The choanosomal skeleton consists of dicranoclone desmas which are covered with prominent slightly mushroom-shaped and smooth tubercles. Articulation is chiefly terminal and relatively weak. Choanosomal microscleres consist mainly of amphiasters/streptasters with long pointed rays.

Megascleres

Dicranoclone desmas covered with prominent, very regular rounded or slightly mushroom-shaped and smooth tubercles: 450-750 µm/35-50 µm.

Dichotriaenes: 375-822 µm long × 179-209 µm diameter (cladome).

Oxeas: 700-4000 × 10-15 µm.

Microscleres

Streptaster (spiraster) with long pointed rays: 40.3-49.2 × 36.0-50.9 µm.

Massive spiraster with short blunt rays: 16.8-25.7 × 8.1-12.4 µm.

Massive spiraster with long blunt rays:

26.2-34.2 × 18.8-22.6 µm.

Spirasters with short blunt rays and spiraster with long blunt rays probably intergrade into a single category.

REMARKS

This new species resembles to some extent C. fulvodesmus (Lévi F Lévi, 1983) , to which it may be closely related, as suggested by the diversity of microscleres and geometry of ectosomal dichotriaenes, which are very similar in both species. Oxeas, present in both species, are much thicker and are usually longer than in C. fulvodesmus .

The new species differs from C. fulvodesmus in shape as well as in desma structure, showing slight resemblance to juvenile (small) specimens of C. fulvodesmus but differing considerably from adult (large) specimens (which are vaseshaped in C. fulvodesmus and cylindrical/clubshaped in the new species). In comparison with the holotype of C. fulvodesmus the desmas of this species are much less massive and less densely covered with tubercles.

Figures

FIG. 2. — A, Aciculites orientalis Dendy, 1905; B, Scleritoderma sp.; C, S. camusi Lévi & Lévi, 1983; D, S. flabelliforme Sollas, 1888; E, Corallistes australis n. sp.; F, Herengeria vasiformis n. sp.; G, H. auriculata Lévi & Lévi, 1988. Scale bars: 1 cm.

FIG. 9. — Corallistes australis n. sp.; A, surface of the choanosomal skeleton; B, details of the surface of the choanosomal skeleton; C, details of dicranoclone desmas; D-F, details of articulation between dicranoclone choanosomal desmas. Scale bars: A, 1 mm; B, 500 µm; C, 200 µm; D-F, 100 µm.

FIG. 23. — Corallistes australis n. sp.; A-E, spirasters with long pointed rays; F-H, massive spiraster with long blunt rays; I-L, massive spiraster with short blunt rays; M, N, cladome of ectosomal dichotriaenes; O, ectosomal dichotriaene. Scale bars: A-H, 10 µm; I-L, 5 µm; M-O, 100 µm.