Clathrina chrysea, Borojevic & Klautau, 2000

Borojevic, Radovan & Klautau, Michelle, 2000, Calcareous sponges from New Caledonia, Zoosystema 22 (2), pp. 187-201 : 189-190

Clathrina chrysea n. sp.

( Fig. 1 )

TYPE MATERIAL. — MNHN-LBIM-C- 1999 -01.

ETYMOLOGY. — From the Greek chrys: “golden”.

MATERIAL EXAMINED. — One specimen.

LOCALITIES. — South coast, Canal Woodin, R- 1360, 28 m.

DESCRIPTION

The single specimen present in the collection has a clathrate cormus typical of the genus, measuring 4 × 1.5 cm, divided into irregular lobular protrusions. It is composed of thin, regularly anastomosed tubes of equal size, without any large superficial water-collecting tubes (photo in Lévi 1998: 74). The colour in life is bright yellow, but the alcohol-fixed specimen is white. The skeleton of the tubes is thin, composed of an irregular meshwork containing only triactines ( Fig. 1 ).

Spicules ( Fig. 1 )

Equiangular and equiradiate triactines. Actines are straight, conical with a rather sharp distal end and measure 105 (± 8.5) / 9.8 (± 1.2) µm at the base. The distal part of the actines is often slightly and irregularly undulated.

REMARKS

The classification of Clathrina is difficult, due to the very few morphological criteria that can be used as descriptors. This is particularly the case of the species that have a single spicule type. The yellow Clathrina are usually classified in the species C. clathrus Schmidt, 1864 , originally described from the Adriatic Sea, and very frequent in the Mediterranean Sea. In previous studies (Solé- Cava et al. 1991; Klautau et al. 1994), we have monitored the genetic characteristics of both allopatric and sympatric sibling species, and we have found that even very faint morphological differences are indicative of genetically distinct species. Based on these genetic studies, we have separated the SW-Atlantic species of yellow Clathrina under the name C. aurea Solé-Cava et al., 1991 from the Mediterranean species C. clathrus . Following the same rationale, we now separate the New Caledonian yellow Clathrina from the other two similar species. Clathrina chrysea n. sp. has bigger triactines than C. clathrus (92 / 5.5 µm) and C. aurea (72 / 5.6 µm), and the major difference that distinguishes the spicules of C. chrysea from C. clathrus and C. aurea is the rather sharp distal end of the actines, which is blunt or rounded in the other two species. The common characteristic of all the species belonging to the group “ clathrus ” is the tendency to have the distal part of the actines slightly undulated. This character has already been pointed out by Haeckel (1872), and although his illustration of the C. clathrus spicules is somewhat arty, it clearly shows the undulated distal part of their actines. The cormus of C. clathrus is characterized by the large superficial tubes that collect the exhalant water and give rise to only a few large oscula. Both C. aurea and C. chrysea have no such tubes, and many oscula open independently at the external surface. The diameter of the tubes is considerably larger in C. aurea , and they are loosely packed, giving the sponge a soft consistency, whilst those of C. chrysea are densely anastomosed and thin, giving the sponge a rather hard consistency.

We propose separating the New Caledonian species from both the Mediterranean and the Atlantic ones. Yellow Clathrina were previously reported from the Indo-Pacific region under the name of C. clathrus , e.g. by Breitfuss (1897) for Ternate, and he was probably referring to C. chrysea , but this question should be addressed in future studies.

Figures

FIG. 1. — Clathrina chrysea n. sp. Triactines of the sponge wall. Scale bar: 30 µm.