Myrmekioderma gyroderma (Alcolado, 1984)

Fig. 7

Diagnostic features.

Massive amorphous to thick encrusting (3.5 cm thick). Brown reddish to orange in color externally, orange internally. Surface highly ornamented by plates and shallow grooves. Oscula in low abundance and irregularly arranged.

Similar species.

Very similar to Didiscus oxeatus, and Myrmekioderma rea; this last species presents a smoother appearance and few thinner grooves. Only a spicule analysis allows to distinguish between them. Didiscus spp. have discorhabds as microscleres, Myrmekioderma rea has only straight trichodragmata, while Myrmekioderma gyroderma has twisted long trichodragmata.

Distribution and abundance.

Shallow and mesophotic reefs, throughout the Caribbean and Gulf of Mexico. At the FGBNMS the species presents low to medium abundance (2-100 individuals) at nine sites.

Ecology.

Coralline algae reefs, algal nodules, lower mesophotic reefs.

Identification.

KR, SK, CA, MCD.

References.

Alcolado 1984; Pomponi et al. 2019.