Clathrina adusta, Worheide & Hooper, 1999

Klautau, Michelle & Valentine, Clare, 2003, Revision of the genus Clathrina (Porifera, Calcarea), Zoological Journal of the Linnean Society 139 (1), pp. 1-62 : 4-5

CLATHRINA ADUSTA WÖRHEIDE & HOOPER, 1999

Type locality: South side of Wistari Reef, Great Barrier Reef, Australia (18 m depth) .

Type: QMG 313665 (holotype /alcohol). South side of Wistari Reef, Great Barrier Reef, Australia, 23∞29.4¢S, 151∞52.8¢E, 18 m depth. Collected by: G. Wörheide, 7 July 1998 .

Colour: The colour of the holotype has changed from white to dark brown while preserved in alcohol ( Wörheide & Hooper, 1999).

Description: The cormus comprises thin, regular and tightly anastomosed tubes which seem bright because of the spicules ( Fig. 1A ). At the apical region, the tubes become larger and have terminal oscula. They are typical water-collecting tubes. In some parts of the cormus, a structure resembling a cortex appears to be present and small cavities can sometimes be found below it. The brownish colour results from the presence of cells with brown granules ( Fig. 1B ).

The skeleton has no special organization, comprising equiangular and equiradiate triactines and tetractines ( Fig. 1C ), the former slightly more abundant. Actines are conical with sharp tips and slightly undulated. The apical actine of the tetractines ( Fig. 1D ) is shorter and thinner than the facial ones, cylindrical, sharp, smooth and straight.

Remarks: This agrees with the original description of C. adusta , if one considers the presence of one size class of triactines. However, this population is very variable and, perhaps, there are in fact two populations of triactines, differing in their sizes. In relation to the shape of the actines, it is considered as conical and not ‘more-or-less cylindrical’. In the original description ( Wörheide & Hooper, 1999), the micrometry of the triactines was:

The organization of the cormus, together with the cells with granules, is the best character to recognize this species

Figures

Figure 1. Clathrina adusta. A, photograph of the holotype (¥ 4). B, Cells with brown granules. C, triactines and tetractines. D, apical actine of a tetractine (arrow). Scale bar = 100 Mm.