THORECTIDAE Bergquist, 1978

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 : 384-391

Family THORECTIDAE Bergquist, 1978

DIAGNOSIS

Thorectid sponges are Dictyoceratida with an anastomosing skeleton of concentrically laminat- ed primary, secondary, and sometimes tertiary, fibres. Primary fibres have an axial, granular pith, which may extend into secondary fibres. The pith is not sharply disjunct from the investing spongin fibre but rather merges into it. Foreign material is often incorporated as a core within the fibres, obscuring the fibre pith when coring material is abundant. The anastomosing fibre skeleton is regular and often rectangular in arrangement. Fibres range in form, from simple fibres to strong, complex fascicles. Primary fibres may be reduced, and are absent in one genus. Zones of disjunction between successive fibrous layers remain tightly adherent, producing an overall homogeneous structure with visible contiguous laminae. Thorectids do not possess the fine filaments seen in sponges of the family Irciniidae . They have small, spherical and diplodal choanocyte chambers. The cortex may be armoured with foreign material; when not armoured, the surface is always coarsely to microconulose.

The Thorectidae comprises twenty-one genera, Cacospongia Schmidt, 1862 , Hyrtios Duchassaing & Michelotti, 1864 , Phyllospongia Ehlers, 1870 , Carteriospongia Hyatt, 1877 , Taonura Carter, 1882 , Aplysinopsis Lendenfeld, 1888 , Thorecta Lendenfeld, 1888 , Thorectandra Lendenfeld, 1889 , Luffariella Thiele, 1899 , Fasciospongia Burton, 1934 , Dactylospongia Bergquist, 1965 , Smenospongia Wiedenmayer, 1977 , Fascaplysinopsis Bergquist, 1980 , Fenestraspongia Bergquist, 1980 , Lendenfeldia Bergquist, 1980 , Strepsichordaia Bergquist, Ayling & Wilkinson, 1988 , Collospongia Bergquist, Cambie & Kernan, 1990 , Petrosaspongia Bergquist, 1995 , Candidaspongia Bergquist, Sorokin & Karuso (1999) , Scalarispongia n.gen., Semitaspongia n.gen. These genera occur throughout the world, with the exception of polar seas. The family Thorectidae was erected by Bergquist (1978) to separate those taxa with laminated fibres and diplodal choanocyte chambers, from what are now recognized as spongiid taxa, characterized by homogenous (unlaminated) fibres. A group of three genera within the Thorectidae , Ircinia Nardo, 1833 , Psammocinia Lendenfeld, 1889 and Sarcotragus Schmidt, 1862 , were characterized by the presence of fine filaments in addition to the fibre skeleton. Bergquist & Wells (1983) suggest- ed that on the basis of the fine filaments and terpene chemistry, a discrete family may need to be established for these three genera. Hooper & Wiedenmayer (1994) reassigned all thorectid taxa, including these three genera, to Irciniidae . This was rectified by Bergquist (1995) who separated this distinct group of filament-bearing genera from the Thorectidae and referred it to the family Irciniidae (Gray, 1867) .

Genus Cacospongia Schmidt, 1862 ( Figs 1A, B ; 2A, B )

TYPE SPECIES. — Cacospongia mollior Schmidt, 1862 by subsequent designation (Laubenfels de 1936).

TYPE MATERIAL.— Lectotype Landesmuseum Johanneum at Graz, LMJG 15405 (dry).

DIAGNOSIS

Massive, low sponges, with an unarmoured surface. The sponge surface is finely and evenly conulose, and externally Cacospongia resembles Spongia . However, because of the harsh, brittle nature of the stratified fibres and the relative paucity of fibres as compared to Spongia species , Cacospongia is easily torn, and thus should never be confused in the field with Spongia , which is tough and elastic. The skeleton comprises relatively fine, concentrically laminated, primary and secondary fibres. Primary fibres are cored, and may form slight fascicles, usually near the sponge surface; secondary fibres are uncored. A granular pith is visible in primary fibres, where it is not obscured by the coring material, and sometimes extend into the secondary fibres. The secondary reticulum is well-developed, relative to primary fibres, branching and irregular ( Fig.1A ). The consistency is soft to firm, compressible and is easily torn. There is low to moderate collagen deposition in the ectosome, and surrounding larger canals within the mesohyl ( Fig.1B ).

No holotype has previously been designated for C. mollior , thus LMJG 15405 is here designated as lectotype. This is one of three specimens from Lesina (LMJG 15048 and LMJG 15411 paralectotypes), the locality mentioned by Schmidt (1862) in his original description. A specimen of

C. mollior was among those presented by the Schmidt collection where only whole, dry Schmidt to Bowerbank at the BMNH and a specimens are figured. We have examined two hand section of this “Adratic” specimen remains other slides of C. mollior, BMNH 1910.1.1.2467

in the Bowerbank collection, BWK 1224 from the Norman collection ( Fig.2B ), and ( Fig.2A ). This specimen gives a better indicationanother from a slide-series in the Topsent collec-

of skeletal characters than can be found in the tion of the Strasbourg Museum ( Fig.1A ). We Desqueyroux-Faundez & Stone 1992 work on have also examined and sectioned BMNH

A

B

C

D

1877.5.21.315, a small, dry fragment from the Bowerbank collection, and BMNH 1883. 12.4.28, a specimen fragment in alcohol. The former is a species of Cacospongia , probably mollior , though is it difficult to be absolutely certain given the condition of the specimen. The latter specimen is C. mollior . A third specimen, BMNH 1867.7.26.2, was also examined and sectioned. This was not Cacospongia , but appeared to be what Schmidt (1862) originally understood as Ditela . The specimen had Spongia -like secondary fibres which dominated the fibre skeleton, plus a very fine fibre reticulum, restricted to the surface regions of the sponge. In addition, we have examined a number of recently collected mollior specimens from the Mediterranean (Niolon, Portofino, Tunisia).

REMARKS

This is the only species of Cacospongia known from New Zealand, but it has not been recorded since its original description.

Genus Scalarispongia n.gen.

Cacospongia serta (Lendenfeld, 1888) n.comb. ( Figs 1E, F ; 2C, D )

( Fig.1C, D )

TYPE SPECIES.— Cacospongia scalaris Schmidt, 1862.

Stelospongia serta Lendenfeld, 1888: 163; 1889: 489, LECTOTYPE.— Landesmuseum Johanneum at Graz, pl.29, fig.6, pl. 30, fig.9. LMJG 15405 (dry).

HOLOTYPE.— Natural History Museum (London) No holotype has previously been designated for BMNH 1886.8.27.166. Cacospongia scalaris and no collection location other MATERIAL EXAMINED.— Port Chalmers. Otago, shal- than Adriatic was given by Schmidt (1862). This low water, 45°49.6’S, 170°37.4’E, 1886, SDCC/- makes the choice of a lectotype from among Schmidt’s NZ076 (BMNH 1886.8.27.166 (fragment of type)). specimens in the LMJG problematic. We have selected LMJG 15416 because it has the best locality data DISTRIBUTION.— Only known from the type locality.(Zara, Sebenicio). Two other specimens in the same collection, LMJG 15409 and LMJG 15410, also from DIAGNOSIS Zara, are designated paralectotypes. Another specimen labelled C. scalaris LMJG 15406 is almost certainly Lendenfeld’s (1888) diagnosis not C. scalaris, and LMJG 15475 carries no locality “ Lobose, massive, irregular sponges, which attain data and is worthless.

a maximum diameter of 160 mm. The continuous Among Adriatic specimens given by Schmidt to surface is covered with very small conuli 0.4 mm Bowerbank was one labelled Cacospongia scalaris now high and 1.2 mm apart. The oscula, which mea- BWK represented 1223 by (Fig a slide.2C). in This the gives Bowerbank an excellent collection depicsure 1.4 mm in width, are scattered chiefly over the tion of skeletal features.

prominent parts. Light brown colour in spirit”. A We have also examined an uncatalogued slide of fragment of the type specimen examined by the Scalarispongia scalaris from the Natural History authors is very pale grey externally. Museum (London) ( Fig.2D ), and another from a slide-series in the Topsent collection of the Strasbourg Museum ( Fig.1E ). In addition, a number of freshly Skeleton collected specimens from the Mediterranean (Niolon,

A relatively fine network of concentrically lami- Portofino, Elba) were made available for study.

nated primary and secondary fibres. Primary ETYMOLOGY.— This new genus name Scalarispongia fibres are cored with foreign inclusions and sec- n.gen., based on the Latin word scalaris , simply means ondary fibres are clear. Secondary fibres are well- ladder sponge, for the regular, often rectangular fibre developed, branching and irregular, as is skeleton of these species. As an aside, the similar Latin characteristic of the genus. The skeleton is punc- word scalarius refers to the men who looked after the ladders in the Roman fire brigades.

tuated by single or small groups of large sand grains. Primary fibres may form slight fascicles in the subsurface region. Primary fibres are DIAGNOSIS

87 µm in diameter (49-155 µm, n = 9) and sec- Massive sponges, forming regular to irregular, ondary fibres are 30 µm in diameter (19-49 µm, pads or cushions. The surface is unarmoured, and

n = 29). covered with fine to coarse conules. The skeleton comprises a spongin fibre reticulum of concentri- Histology cally laminated primary and secondary fibres, The diplodal choanocyte chambers are spherical to arranged in a regular, ladder-like pattern oval,and are 31 µm in diameter (42-63µm, n =20). ( Fig.1E ). The meshes of the skeletal reticulum There is a subdermal band of collagen, and minor are often, though not always, precisely rectangudeposits scattered through the mesohyl. lar, with secondary fibres forming almost perfect right angles to primary fibres. Primary fibres are to the new genus Scalarispongia diagnosed above, cored with foreign material and secondary fibres but is distinguished by its enhanced collagen are clear. Primary fibres do not form fascicles but deposition and the comparatively irregular skelein one of the slides examined (ex-Topsent collec- tal reticulum. tion), some secondary fibres formed light webbing, rather than discrete secondary fibres, between the primary fibres. The mesohyl is mod- Semitaspongia incompta n.sp. erately and evenly infiltrated with collagen ( Fig.3 ) ( Fig.1F ). This new genus is typified by the wellknown species described by Schmidt (1862) as HOLOTYPE.— Hauraki Gulf. Maori Island, Leigh, Cacospongia scalaris . 36°17.7’S, 174°49.0’E, 17 2.I.1993, m, NMNZ

POR459 (= SDCC/ NZ 031).

PARATYPE.— Hauraki Gulf. Maori Island, Leigh,

Semitaspongia n.gen. 36°17.7’S, 174°49.0’E, 17 m, 2.I.1993, SDCC/

( Fig.3 ) NZ 026.— Taranga (Hen Island), ° 35 58.1’S,

174°44.8’E, 12-15 m, 8.XII.1992, SDCC/ NZ 030.

TYPE SPECIES.— Semitaspongia incompta n.sp. ETYMOLOGY.— The species name reflects the untidy HOLOTYPE.— Hauraki Gulf. Maori Island, Leigh, or scruffy appearance of this species, with its emergent 36°17.7’S, 174°49.0’E, 17 m, 2.I.1993, NMNZ fibres, and irregularly fleshed and unfleshed fibre POR459 (= SDCC/ NZ 031). skeleton. ETYMOLOGY.— The name Semitaspongia is based on DISTRIBUTION.— This species is only known from the type locality and Taranga (Hen Island).

semita, a Latin word for footpath. The same word was employed more loosely by poets, who used it to refer to tracks in the sky. Hence Semitaspongia literally DIAGNOSIS means footpath or track sponge, referring to the foot- A low, massive species, forming a highly irregular path-like tracks of choanocyte chambers in the meso- pad, comprising living tissue and exposed fibre hyl. network, which may be in the ratio of 1/ 1 in some specimens. The surface has numerous, fine to

DIAGNOSIS coarse conules, with long dendritic emergent ter- Massive sponges, forming regular to irregular minal fibres. Thin ridges of pinacoderm are pads, blunt fingers or lobes, or cushions. The sur- stretched between some adjacent conules on face is conulose and unarmoured. The skeleton coarsely conulose specimens. The exposed fibre consists of an irregular to regular reticulum of reticulum is an internal feature as well, where concentrically laminated primary and secondary apparently solid areas of sponge have internal pockfibres. Primary fibres are cored and secondary ets of unfleshed fibre skeleton. The sponge is soft fibres are clear. Primary fibres may be slightly fas- to moderately firm, and compressible. Colour is cicular, typically just beneath the cortex. A cen- light to medium grey externally and light grey to tral pith is visible in primary fibres, though it brownish grey internally. Fibres are light to may be obscured where fibres are cored, and can medium golden brown. All three specimens are c. sometimes be seen extending into secondary 60-80 mm in diameter × 5-20 mm thick. fibres. The consistency is soft to firm, compressible and is easily torn. There is moderate to abun- Skeleton dant collagen deposition in these species, Comprised of concentrically laminated primary typically in subdermal regions, around individual and secondary fibres. The skeleton is unusual, canals and canal beds, and in some cases it may ranging from an occasional regular and rectanguconstitute up to 40% of the mesohyl volume. In lar reticulum, of low to moderate density, to the some species, the choanocyte chambers are more typical tangled, relatively high density netarranged in tracks or in single file through col- work. Primary fibres are axially to fully cored, and lagenous deposits ( Fig.3F ). This genus is closestsecondary fibres are uncored. Pith is visible in primary, and some secondary fibres. In places, fibres form complex, tangled fascicles, and vary greatly in diameter. Primary fibres are 194 µm in diameter (87-825 µm, n = 34) and secondary fibres are 78 µm in diameter (29-146 µm, n = 28).

Histology

The choanocyte chambers are diplodal, and spherical to oval in shape. They are loosely scattered throughout the mesohyl, and in some places arranged in tracks through beds of collagen. Choanocyte chambers are 29 µm in diameter (23-39 µm, n = 21). The mesohyl is heavily impregnated with collagen.

REMARKS

Typically irregular and unkempt, which may contribute to it being overlooked. An untidy looking species, which is readily distinguishable.

Figures

FIG. 1. — A, Cacospongia mollior (ex-Topsent collection, Strasbourg), fibre skeleton; B, Cacospongia mollior, showing histological detail; C, Cacospongia serta, holotype, BMNH 1886.8.27.166 (fragment = SDCC/NZ076), fibre skeleton; D, Cacospongia serta holotype, BMNH 1886.8.27.166 (fragment = SDCC/NZ076), detail of fibre skeleton; E, Scalarispongia scalaris (ex-Topsent collection, Strasbourg), fibre skeleton; F, Scalarispongia scalaris, showing histological detail. Scale bars: 500 µm.

FIG. 2. — A, Cacospongia mollior (Natural History Museum, London, Bowerbank collection 1224). Labels are probably in Bowerbank’s handwriting; B, Cacospongia mollior, BMNH 1910.1.1.2467. Labels are probably in Bowerbank’s handwriting; C, Scalarispongia scalaris (Natural History Museum, London, Bowerbank collection 1223). Labels are probably in Bowerbank’s handwriting; D, Scalarispongia scalaris (Natural History Museum, London, uncatalogued slide). Labels are probably in Bowerbank’s handwriting.

FIG. 3. — Semitaspongia incompta n. sp.; A, holotype, NMNZ POR459 (= SDCC/NZ031); B, paratype SDCC/NZ026; C, paratype SDCC/NZ030; D, holotype, NMNZ POR459 (= SDCC/NZ031), a more regular section of fibre skeleton; E, paratype SDCC/NZ030, detail of the typical irregular fibre skeleton. Note the appearance of the fibres themselves, in contrast to the relatively clear, finely laminated fibres of Scalarispongia scalaris in Fig. 1E; F, holotype, NMNZ POR459 (= SDCC/NZ031), histological detail, showing tracks of choanocyte chambers (upper centre and lower right of photo) through a collagenous deposit. Scale bars: D, E, 500 µm; F, 100 µm.