Geodia simplex, , Schmidt, 1870

Cárdenas, Paco, Rapp, Hans Tore, Klitgaard, Anne Birgitte, Best, Megan, Thollesson, Mikael & Tendal, Ole Secher, 2013, Taxonomy, biogeography and DNA barcodes of Geodia species (Porifera, Demospongiae, Tetractinellida) in the Atlantic boreo-arctic region, Zoological Journal of the Linnean Society 169 (2), pp. 251-311 : 298

GEODIA SIMPLEX SCHMIDT, 1870

Geodia simplex, Schmidt, 1870: p. 70 ; Arndt, 1913: p. 112; Burton, 1930: p. 490; 1946: p. 856.

Type locality and deposition of holotype: Egedesminde , West Greenland, 50–90 m, ZMUC-DEM-319 (wet specimen). Burton (1946) also speaks of a Schmidt spicule preparation from the type, still in the BMNH collection today ( BMNH 70.5.3.79).

Discussion: Arndt (1913) identified with hesitation a small specimen from Norway as G. simplex ; the specimen has not been located. Burton (1946), after an examination of spicule preparations from the type material from Greenland, concluded that G. simplex is probably identical to G. cydonium , which explains why Burton (1959) later mentioned G. cydonium as occurring in Greenland and Norway. Also, Koltun (1966: 57) doubted the existence of G. simplex as an independent species. We have inspected the holotype, a whole specimen cut in two. It is a rounded lump, measuring c. 7 cm in diameter and 3 cm in height; the surface is damaged in some areas, and algae are growing on it. The cortex is 1 mm thick. The spicule repertoire is clearly that of G. cydonium from the Mediterranean Sea. However, there must be a mistake, most likely from Schmidt’s side, as the label is in his handwriting. The algae growing on the specimen do not occur in Greenland; on the contrary, one of the species is Mediterranean, another one Mediterranean–southern boreal (Dr Poul Møller Pedersen, pers. comm.). We therefore confirm that G. simplex is a junior synonym of G. cydonium . As molecular results suggest that G. cydonium is a species complex ( Cárdenas et al., 2011), only a thorough morphological revision of this complex will tell us to which species group G. simplex belongs.