Crambe Vosmaer, 1880

Maldonado, Manuel, Carmona, M. Carmen, Van Soest, Rob W. M. & Pomponi, Shirley A., 2001, First record of the sponge genera Crambe and Discorhabdella for the eastern Paci ® c, with description of three new species, Journal of Natural History 35 (9), pp. 1261-1276 : 1263-1264

Crambe Vosmaer, 1880

Diagnosis. Encrusting sponges characterized by having aster-like desmas (astroclones or sphaeroclones), along with a category of large choanosomal (tylo)styles, a category of small ectosomal subtylostyles, and one or two categories of anchorateunguiferate isochelae. Irregularly spiny microxeas occur in some species.

Remarks. It has long been recognized that, for unknown reasons, most populations of Crambe crambe and some of Crambe acuata produce neither desmas nor isochelae (e.g. Boury-Esnault, 1971; Vacelet et al., 1976). This fact has largely complicated both species and genus diagnoses in Crambe . However, it was recently found that laboratory populations of C. crambe reared in seawater experimentally enriched with silicic acid produce up to four spicule types, desmas and isochelae included, that were otherwise missing in most natural populations ( Maldonado et al., 1999). Therefore, it must be concluded that production of asteroid desmas and isochelae is a genetic trait shared by all individuals of all Crambe species. The skeletal reduction observed in many natural populations of C. crambe does not appear to have a genetic basis, but seems to be a phenotypic skeletal inhibition induced by limiting levels of silicic acid in sublittoral waters. Consequently, the presence / absence of desmas and isochelae must be used cautiously in the taxonomy of both Crambe and other crambeids.

The genus Crambe is here reported for the ®rst time from the Paci®c Ocean. It is noteworthy that it has not been reported to date from the well-known Caribbean sponge fauna or in nearby zones of the Central Paci®c, such as the Galapagos Islands, which have recently been surveyed (Desqueyroux-FauÂndez and van Soest, 1997; authors, unpublished data). Nevertheless, the presence of the genus in the western Paci®c stratigraphic sediments can be inferred from the fossil sphaeroclones found in Lower Tertiary strata of Oamaru ( New Zealand). Such characteristic sphaeroclones, though formerly attributed to the genus Vetulina by Hinde and Holmes (1892), most likely belong to a fossil species of Crambe ( Uriz and Maldonado, 1995) , namely Crambe oamaruensis ( Hinde and Holmes, 1892) .