Family Kophobelemnidae

Sclerobelemnon theseus Bayer, 1959

Sclerobelemnon theseus Bayer, 1959b:33, figs. 18-21.

Remarks. This species has a club-like shape with the stalk slightly longer than the rachis. The distal end of the peduncle is slightly pointed and not inflated to any extent. The examined specimen is about 7 mm at its widest point and 65 mm in length. The rachis contains some exert autozooids but most are contracted, with minute, indistinct siphonozooids scattered between calyces. The autozooids are arranged in 12 indistinct longitudinal rows, leaving a bare dorsal streak along the back of the colony. The axis is slightly flexible and the coenenchyme is tough and rubbery. The color of the colony is creamy white in alcohol.
The autozooids contain sclerites in the form of plates that resemble double sided axes or plates with a medial constriction, reaching 0.3 mm in length. Some plates have serrated edges or a distal ridge along the edge. The body wall contains similar plates with a medial constriction and serrations, and the stalk contains smaller plate-like bodies. This is the first record of this species in the South Atlantic Bight, although one specimen in the USNM from Cape Fear is identified as Sclerobelemnon sp. and was not examined for this work.

Atlantic distribution: Charleston, 79 m, Gulf of Mexico (unknown depth), Surinam, Trinidad, 57 m (Bayer, 1959b; Bayer, 1961; Williams, 1995; NMNH collections; SERTC collection).

Figure 1. Sclerobelemnon theseus, preserved specimen (S2312); left) whole colony; right) close up of rachis showing dorsal streak and polyps.

Figure 2. Sclerites of Sclerobelemnon theseus (S2312), from stalk. Scale bar = 50 µm.