Clathrina aurea Solé-Cava, Klautau, Boury-Esnault, Borojevic & Thorpe, 1991

Klautau, Michelle & Borojevic, Radovan, 2001, Sponges of the genus Clathrina Gray, 1867 from Arraial do Cabo, Brazil, Zoosystema 23 (3), pp. 395-410 : 401-403

Clathrina aurea Solé-Cava, Klautau, Boury-Esnault, Borojevic & Thorpe, 1991

( Fig. 4 ; Table 4)

Clathrina aurea Solé-Cava et al., 1991: 382 , tabs 1; 2.

TYPE MATERIAL. — Holotype, 15.XI.1987, coll. E. Hajdu, Muséum national d’Histoire naturelle, Paris ( LBIM.C.1989.1).

TYPE LOCALITY. — Arraial do Cabo (Anjos), Rio de Janeiro, Brazil.

ETYMOLOGY. — From Latin Aureus: golden. For the yellow colour of the cormus.

MATERIAL EXAMINED. — Oasis Coralino. Forno, Anjos, Enseada, Pontal do Atalaia, Pedra Vermelha, several specimens collected in small crevices in the Oasis Coralino.

DESCRIPTION

Living specimens of this species have a clathrate golden-yellow cormus, which becomes beige in alcohol. The cormus is composed of large, irregular and loosely anastomosed tubes, where several oscula are spread. No water-collecting tubes are present ( Fig. 4A ). Special characteristics were not found on the histological slides.

The skeleton has no special organisation. It is composed of equiangular and equiradiate triactines ( Fig. 4B ; Table 4). Actines are characteristically undulated at the distal part, and their ends are rounded.

C. aurea is common in the warm water of the Oasis Coralino. Its habitat is sciaphilous which means it is exposed to very little sunlight, and protected from the action of waves. It is frequently found on the roof of small caves or in crevices.

REMARKS

Clathrina aurea is morphologically very similar to its sibling C. clathrus (Schmidt, 1864) from the Mediterranean Sea. Both species are yellow and have only triactines with undulate actines and rounded ends. Comparing both populations by allozyme analysis (Solé-Cava et al. 1991), we found very low levels of genetic identity between them, indicating no gene flow between the Mediterranean and the Atlantic populations and, consequently, no cospecificity. Although they are morphologically very similar, some differences can be recognised between specimens of the two species. The spicules of C. clathrus are larger

TABLE 5. — Clathrina brasiliensis Solé-Cava et al., 1971 , spicule size.

(92 µm [± 7 µm] / 6 µm [± 1 µm]) than those of C. aurea . Moreover, the organisation of the cormus in each species is different. While C. aurea has several oscula spread through the tubes, C. clathrus has water-collecting tubes, i.e. tubes that collect the excurrent water and conduct it to a few apical oscula. We could also consider the shape of the end of the actines, which is more rounded and protuberant in C. clathrus than in C. aurea .

Another species that can be confused with C. aurea is its New Caledonian sibling C. chrysea Borojevic & Klautau, 2000 . C. chrysea also has no water collecting tubes. However, instead of triactines with round ended actines, the triactines of C. chrysea are sharp and they are larger (105 µm [± 9 µm] / 10 µm [± 1 µm]) than those of C. clathrus .

Figures

FIG. 4. — Clathrina aurea Solé-Cava et al., 1991; A, underwater photo by E. Hajdu; B, spicules, holotype (LBIM.C.1989.1), triactines. Scale bars: A, 1 cm; B, 100 µm.