Description

“Asbestopluma belgicae (Topsent) (Plate VII, 1 - 7)

 

Topsent, 1902:23, pl. I, fig. 4, pl. III, fig. 8 (Cladorhiza).

 

LOCALITIES. St. 164, 460.

 

DIAGNOSIS. Body formed of a stalk whose upper part bears a verticil of branches grouped together (3 - 10 branches). The lateral, slender branches reach 18 mm in length; sometimes they are much shorter and appear as short tuberculated outgrowths with a maximum length of 2 - 3 mm. In this case the upper part of the sponge is flattened. Along the stalk there are about 10 verticillated groups of branches. Between them the stalk is devoid of branches. The sponge reaches a height of 39 cm; the branching part of the stalk is 5 mm wide, the lower part of the stalk 8 mm wide. The axial skeleton is formed by a dense longitudinal fascicle of styles. The dermal layer of the stalk is formed of small tylostyles.

 

Spicules. Macroscleres: styles (modified also to subtylostyles) — 0.750 -1.200 mm long and 0.012 - 0.028 mm wide; tylostyles of the dermal layer of the stalk (curved and with small spinules) up to 0.250 mm long and 0.0025 mm wide. Microscleres: anisochelas — 0.010 - 0.012 mm long and sigmas — 0.027 - 0.033 mm long. The great majority of the styles (or subtylostyles) of this species is about 1 mm long; there is a small number of subtylostyles about 0.8 mm long, which are found in the axial skeleton and in those parts of the body which are adjacent to the stalk.

 

DISTRIBUTION. Antarctic shores (Wilhelm II Coast, Bellingshausen Sea, South Shetland Islands). Depth 370 - 569 m.”

 

(Koltun, 1964)