Mycale (Carmia) cf. toxifera (Dendy, 1896)

(Fig. 28 A–G) (Tab. 13)

Examined material. Sample SC. O’ahu: Hawai’i, O’ahu Island, Shark’s Cove, 14 m, 28 March 2005; sample SC2: Hawai’i, O’ahu Island, Shar’s Cove, depth between 9–15 m, 11 June 2007.

Description. Thinly encrusting sponge, about 1 mm thick, covering two fragments of Carijoa riisei, up to 5 cm long. Consistency gelatinous. In situ dull orange or ochre (Fig. 28 A), brownish in ethanol (Fig. 28 B).

Skeleton. No specialized ectosome. Choanosome made of small tracts of mycalostyles running to the surface and scattered microscleres (Fig. 28 C).

Spicules. Mycalostyles straight and very thin, with a well pronounced head (Fig. 28 D), 130 – 245 x 2 – 2.5 μm. Palmate anisochelae; the upper part with a well-formed frontal ala, and the basal portion with a single frontal ala and two basal spur-like projections, visible with SEM (Fig. 28 E), 10–16.2 μm. Sigmas very rare, regular in shape and very thin (Fig. 28 F), 17.5–32.2 μm. Toxas with a slight central flexion and bent tips (Fig. 28 G), 45–212.5 μm. Refer to Tab. 13 for complete measurements.

Distribution and remarks. Australia. The only two Indo-Pacific species of this subgenus that have a similar spicule complement (mycalostyles, sigmas, anisochelae and toxas in a single category) are M. (C.) suezza (Row, 1911) and M. (C.) toxifera . Mycale (C.) suezza has larger spicules: mycalostyles (320 – 330 x 4 µm), sigmas (70 μm), anisochelae (40 µm), and toxas (210–310 µm). The spicule sizes of M. (C.) toxifera (mycalostyles 200 x 4 µm, anisochelae about 10 µm, toxas about 95 x 1.7 µm and very rare sigmas of about 12 µm) are close to those of our specimens.

Dendy (1896) described this species as a massive sponge with a very lax and irregular main skeleton of sinuous, branching and multispicular fibres. Our specimens mainly differ in the thickness of the mycalostyles (very thin). The bad conservation status of the Hawaiian specimens did not allow us to examine the organization of the skeleton, thereby preventing a conclusive species assignment.