Xestospongia muta (Schmidt, 1870)

Fig. 25

Diagnostic features.

Barrel-shaped. with a wide apical vent surrounded by a 2-5-cm wall which thickens towards the sponge base. Smaller specimens may present as a cone-shaped form. Red-brown externally, tan internally. Surface ranges from smooth to irregularly ridged or pitted. Few small openings (2-3 mm in diameter) may be oscula. Inner wall without detachable dermis, rough. The detachable dermis ends on the inside rim of the vent. The atrial cavity extends to ca. half the cup height. Consistency is brittle, easily crumbled.

Similar species.

Xestospongia sp. nov. 1, described below, is shorter, with a flat top, thicker rimmed walls, and much smaller atrium than X. muta .

Distribution and abundance.

An iconic species from shallow reefs in Florida, throughout the Caribbean, to southeastern Brazil, southern GOM, and northwestern GOM at FGBNMS. Mesophotic reefs in Cuba, south Florida, northwestern GOM at FGBNMS, and east GOM at Pulley Ridge. Reed (2022) reports it at three banks in FGBNMS (51-69 m deep).

Ecology.

Coral reefs, coral communities, coralline algae reefs, algal nodules.

Identification.

John Reed, MCD.

Reference.

Díaz et al. 2019; van Soest 1980.