Clathrina tetractina, Klautau & Borojevic, 2001

Klautau, Michelle & Borojevic, Radovan, 2001, Sponges of the genus Clathrina Gray, 1867 from Arraial do Cabo, Brazil, Zoosystema 23 (3), pp. 395-410 : 408-409

Clathrina tetractina n. sp.

( Fig. 9 ; Table 9)

TYPE MATERIAL. — Holotype, 14.VI.1987, coll. G. Muricy, The Natural History Museum, London ( BMNH 1999.9.16.33).

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

ETYMOLOGY. — From the Greek Tetra : four. For the presence of only tetractines.

MATERIAL EXAMINED. — Oasis Coralino. Pedra Vermelha, one specimen.

DESCRIPTION

The cormus of this species is white in life and in alcohol. It is composed of large, irregular and loosely anastomosed tubes. Large superficial tubes (water-collecting tubes) collect the excurrent water, converging to a few apical oscula. No special characteristics were found on the histological sections.

The skeleton has no special organisation, and it is composed only of tetractines ( Fig. 9A ), although a few, rare triactines can be found. Spicules are equiradiate and equiangular, but parasagittal spicules are also present. Actines are conical, with sharp ends, and they are slightly undulated at the distal part. The apical actine of the tetractines ( Fig. 9B ; Table 9) is very thin even at the base. It is straight, sharp, long and smooth, and it is projected into the tubes.

Only one specimen of this species was found in the Oasis Coralino. This species has a sciaphilous habitat.

REMARKS

This species is morphologically similar to C. contorta (Bowerbank, 1886) in the shape of the tetractines, particularly the apical actine, which is very thin and long. However, it has no triactines or diactines as in C. contorta .

In relation to C. quadriradiata n. sp., the only similarity is the presence of tetractines as main spicule. The shape of the actines (including the apical actine), however, is different, as is their size. Moreover, while triactines can be found in

C. quadriradiata n. sp., in C. tetractina n. sp. they are very rare.

Figures

FIG. 9. — Clathrina tetractina n. sp., holotype (BMNH 1999.9.16.33); A, spicules of tetractines; B, apical actine (arrow) of a tetractine. Scale bars: A, 100 µm; B, 50 µm.