Semitaspongia glebosa, de & Bergquist, 2000

de, Steve & Bergquist, Patricia R., 2000, Two new genera and five new species of the “ Cacospongia ” group (Porifera, Demospongiae, Dictyoceratida), Zoosystema 22 (2), pp. 383-400 : 391-395

Semitaspongia glebosa n.sp.

( Fig.4 )

HOLOTYPE.— Canyons. Goat Island , Leigh, Northland, 36°16.3’S, 174°47.7’E, 10 m, 1.VIII.1992, C. N. Battershill, NMNZ POR457 (= SDCC/ NZ 081).

PARATYPES.— Canyons. Goat Island, Leigh, Northland, 36°16.3’S, 174°47.7’E, 12 m, 1.VIII.1992, C. N. Battershill, SDCC/ NZ 080. — Leigh Harbour, Northland, 36°17.7’S, 174°48.9’E, 10-15 m, 1.VIII.1992, C. N. Battershill, SDCC/ NZ 078.

ETYMOLOGY.— The name glebosa refers to this species resemblance to clods of earth, from the Latin gleb, clod of earth.

DISTRIBUTION.— Recorded only from the vicinity Leigh, Northland, in 10-15 metres of water, encrusting vertical rock walls.

DIAGNOSIS

An encrusting species, forming a low, irregular pad, firmly attached to the substratum. The surface is conulose and slightly undulating. SDCC/ NZ 078 has two small turrets, 2-7 mm high, each with a small terminal oscule, ≤ 2 mm

in diameter, otherwise, there are no visible oscules. This species is dark brownish grey externally and light brown greyish brown internally. Fibres are dark and are clearly visible within the pale matrix. The consistency is soft and compressible. The holotype is 65 mm × 55 mm × 5-12 mm thick. Paratypes are 75 mm × 45 mm × 5-10 mm thick (SDCC/ NZ 080) and 70 mm × 2 5-5 0 mm × 5-1 2 mm thick (SDCC/ NZ 078).

Skeleton

A moderately dense network of primary and secondary fibres. Fibres are concentrically laminat- ed in cross-section and often a dark axial pith is visible, particularly in primary fibres, and sometimes extending into secondary fibres. Primary fibres can form loose, tangled groups of coalescing fibres, and are axially to fully cored with foreign sponge spicules and debris; they may also show light fascicles. A small amount of scattered interstitial detritus, mainly sponge spicules may be present. Secondary fibres may form ladders between primary fibres or branch before connecting with primary fibres, and rarely, may contain some axial coring. Primary fibres are 126 µm in diameter (68-262 µm, n = 61). Secondary fibres are 60 µm in diameter (29- 184 µm, n = 51).

Histology

The diplodal choanocyte chambers are spherical to oval, and are 34 µ m in diameter (23-44 µ m, n = 56). A marked layer of collagen is evident dermally, and there is heavy deposition around larger canals, groups of canals and foreign material within the mesohyl. Choanocyte chambers can be observed embedded within the collagen, arranged in lines or in small blocks.

of

REMARKS

Another inconspicuous species, characterized by its simple, encrusting form and conulose surface. This species would be difficult to identify in the field, and could easily be confused with other dictyoceratid species, e.g. Ircinia , of similar form. However, this problem is easily solved once histological slides have been made and examined.

Semitaspongia nigrachorda n.sp. ing attached at several points. The surface is finely

( Fig.5 ) conulose, with single or multiple terminal emergent fibres. Pores are irregularly scattered on the under-

HOLOTYPE.— Poor Knights. 35°28.5’S, 174°44.5’E, surface of the holotype, and there is one small clus-

10-15 m, 25.V.1983, J. Fromont, NMNZ POR456

(= SDCC/ NZ 159). ter of pores on one side of the upper surface. There are a number of other invertebrates growing on the

ETYMOLOGY.— The species name highlights this sponge surface, including an encrusting bryozoan

species black-lined appearance where the skeletal reticulum is visible externally on the holotype. and two dendroceratid sponges. Colour is light brownish grey throughout. Fibres range in colour

DISTRIBUTION.— Only known from the type locality.from light brownish grey to dark brown. They are visible at the surface in places, where they resemble

DESCRIPTION fine, dark-coloured veins. Its consistency is moder-

A low, massive species, forming an irregular pad, ately soft and compressible. The holotype is most of which is raised off the substratum, remain- 130 mm × 35-75 mm and 15-50 mm high.

Skeleton stretched between adjacent conules, forming a An irregular, moderate density skeleton of coarse network of ridges, producing an irregular geoprimary and secondary fibres. Primary fibres are metric pattern. The sponge has a number of low strongly laminated, with a marked pith; they may conical turrets scattered over the upper surface contain foreign debris, mainly sponge spicules, as and sides; some turrets appear merely as slight an axial core, but most are clear of inclusions. extensions of the coarsely conulose surface. Each Primary fibres may also form fascicles. Secondary of the turrets bears a single terminal oscule. Pores fibres attach directly to primary fibres, or branch, (≤ 1 mm in diameter) are abundant and scattered sometimes becoming entangled, such that the over the sponge, particularly around the sides. distinction between primary and secondary fibres On the surface there are patches of emergent may not always be clear. Secondary fibres are fibres, either single or branched. The pinacoderm uncored. Primary fibres are 631 µm in diameter is translucent and the sponge is soft, compressible (291-970 µm, n = 12) and secondary fibres are and fleshy. Colour both internally and externally 184 µm in diameter (97-291 µm, n = 9). is light greyish brown to pinkish grey. Fibres are light straw to light golden brown, and the oscular

Histology rim may be slightly darker coloured. These The diplodal choanocyte chambers are spherical sponges were distinctly slimy when collected. to oval, and 29 µm in diameter (26-31 µm, The holotype is 135 mm long × 75 mm wide × n = 20). There is a band of collagen ectodermally, 70 mm high; the paratype is 125 mm long around larger canals within the sponge matrix × 65 mm wide × 60 mm high. and often around skeletal fibres. Of the five new species described here, this sponge has the least Skeleton amount of collagen in the mesohyl. The fibre skeleton of concentrically laminated primary and secondary fibres, is regularly to

REMARKS irregularly disposed. Primary fibres are axially to This species is characterised by its coarse, some- fully cored, usually with sponge spicules, but also what irregular fibre skeleton, along with the dark with fine sand and grit; the fibre coring obscures fibres on a pale background, and its irregular, the fibre pith. Secondary fibres are generally upright form. uncored, though irregular, partial coring may be seen and these fibres may branch. The fibre pith is visible extending into some secondary fibres.

Primary fibres are 146 µm in diameter (97-

Semitaspongia pulvinata n.sp. 243 µm, n = 30) and secondary fibres are 87 µm

( Fig.6 ) in diameter (58-126, n = 16 µm). These two specimens were originally kept as a single sample.

3

HOLOTYPE km east. of — Little Hauraki Barrier Gulf Island . Stn G, 20 11 m (“ Ikatere , NMNZ ”), Histological sections were taken from both POR454 (= SDCC/ NZ 156), pieces. They were subsequently considered to be separate specimens, rather than two pieces of the

PARATYPE.— Hauraki Gulf. Stn G11 (“Ikatere”), 3 km east of Little Barrier Island, 20 m, SDCC/ NZ 251. same specimen. Unfortunately it is unknown which of the two specimens the histological sec-

DISTRIBUTION.— Only known from the type locality,tions figured represent. in the Hauraki Gulf. ETYMOLOGY.— The species name for this sponge, pul- Histology vinata reflects its resemblance to a cushion or pillow. Choanocyte chambers are spherical to oval,

diplodal, and are 31 µm in diameter (21-39 µm,

DIAGNOSIS n = 21). The mesohyl of this species comprises at A massive, compact species. The surface is irregu- least 30-40% collagen, with distinct concentralar, varying from very finely to coarsely papillose, tions around canals, canal beds and surrounding to conulose. In coarse areas, the pinacoderm is foreign organisms living within the mesohyl.

D, fibre skeleton; E, histological detail. Scale bars: 500 µm.

Collagen also dominates the surface regions, giving this species its fleshy appearance. The choanosome is arranged in blocks, and choanocyte chambers do not form tracks through collagen deposits as seen in other species.

REMARKS

This species is well characterized by its massive, cushion-like form, fleshy appearance and compressible texture, and in terms of its histology, by the high density of collagen deposition within the mesohyl.

Figures

FIG. 4. — Semitaspongia glebosa n. sp.; A, holotype, NMNZ POR457 (= SDCC/NZ081); B, paratype, SDCC/NZ080; C, paratype, SDCC/NZ078, fibre skeleton; D, paratype, SDCC/NZ078, detail of fibre skeleton; E, holotype, NMNZ POR457 (= SDCC/NZ081), with some unidentified structures at the surface of the sponge, which superficially resemble fibres; F, holotype, NMNZ POR457 (= SDCC/NZ081), histological detail. Scale bars: C-E, 500 µm; F, 250 µm.

FIG. 5. — Semitaspongia nigrachorda n. sp.; A, top view; B, bottom view, showing dark fibres visible at or near surface; C, fibre skeleton (surface at lower right); D, fibre skeleton; E, fibre skeleton (surface at top left). Scale bars: 500 µm.

FIG. 6. — Semitaspongia pulvinata n. sp.; A, holotype, NMNZ POR454 (= SDCC/NZ156); B, paratype, SDCC/251; C, fibre skeleton;