Aplysilla glacialis (Merejkowsky, 1878)

Fig. 7

Simplicella glacialis Merejkowsky, 1878: 264–265 .

Aplysilla glacialis – de Laubenfels 1948: 164–165, fig. 24.

Material examined

SWEDEN • 1 spec.; Saltbacken; 59.0832° N, 11.2242° E; 24 Apr. 2018; Mats Larsson leg. [MM-180424-1]; SCUBA; LAR-180424-4587–4588; voucher: GNM Porifera 990 .

Description

An encrusting sponge of which we collected a fragment measuring 7 mm long by 6 mm. Colour in vivo is dirty white, turning snow white in ethanol. The surface is conulose (Fig. 7A) with smaller/shorter conules than A. sulfurea . The surface presents a network composed of polygonal areas of translucent membrane with multiple ostia. The osculum has a high translucent rim almost papillae-like.

Skeleton

The skeleton of the specimen of Aplysilla glacialis closely resembles that of Aplysilla sulfurea (Fig. 7B).

Ecology and distribution

The original distribution is the White Sea, next to the Barents Sea (Merejkowsky 1878a). In synonymy, the species has records from the east South Pacific up to California and within the west South Pacific, specifically in Australia. However, this is likely incorrect, see Remarks below.

Remarks

Our specimen conforms to the description of Aplysilla glacialis (Merejkowsky 1878b) which has its type locality in the White Sea. De Laubenfels (1948) synonymised several other names with A. glacialis, namely: a) Aplysilla arenosa Hentschel, 1929, from the North Atlantic a preoccupied name later substituted with Aplysilla arctica by de Laubenfels (1948), b) Aplysilla palida Lendenfeld, 1889, from Australia, and c) Aplysilla lendenfeldi Thiele, 1905, from southern Chile. The latter two synonymies are dubious since they would imply a cosmopolitan distribution for A. glacialis . The species A. arctica is reported from northern Norway (Hentschel 1929), and Hentschel (1929) considers its main distinguishing feature to be strong content of organic foreign material. However, the descriptions for A glacialis do not mention the inclusion of the foreign particles. It is a possible that A. arctica constitutes a junior synonym of A. glacialis, but further studies are warranted to support this hypothesis.