Cystodytes solitus

Cystodytes solitus Monniot, 1988

(Figure 25)

Cystodytes solitus Monniot F, 1988: 223 fig 12 a–c, New Caledonia; Monniot F & Monniot C. 2006: 133 fig. 26B, and synonymy Madagascar, Mauritius.

Stations. TA 35 (MNHN A3 CYS 137). TA 52 (MNHN A3 CYS 138).

Salomon Isl. Bellona, 21° 26.403 S –158° 58.139 E, 6m, 21/04/2002 (MNHN A3 CYS 125) P. Laboute coll.

The colonies form thick crusts with a round edge (Fig. 25A,B). The tunic is brown and the surface layer contains small round spicules around the siphon apertures (Fig. 25 B). The zooids are arranged in circular systems, in which the atrial openings are tightly grouped in the centre. The zooid apertures appear in a dark brown colour. The tunic is opaque and does not let see the calcareous plate-like capsules encasing the zooids. Small spicules, in balls of needles, are scattered between the capsules. The dark brown zooids (in formalin) have the general structure of the genus. A pedunculate brooding pouch (Fig. 25 C) is appended at the oesophagus level and contains a single brown larva 1.1mm long (Fig. 25 D).

The characteristic look of this species is due to the abundant didemnid- like spicules at the surface layer of the colony and the dark tips of the siphons (Fig. 25A,B). The large dark larva in a pedunculate brooding pouch ascertains the identification which is always difficult in the genus Cystodytes .