Megalocranchia (Voss and Voss, 1983)

Bolstad, K. S. R., Perez, J. A. A., Strugnell, J. M. & Vidal, E. A. G., 2014, Cranchiids of the South Atlantic Mid-Oceanic Ridge: results from the first southern MAR-ECO expedition, Journal of Natural History 49 (21), pp. 1351-1371 : 1363

The single Megalocranchia sp.

( Figure 5D) collected was the largest cranchiid specimen, at ML 59.2 mm. Its tentacle club ( Figure 6B ) bore ~30 transverse rows of four suckers. Carpus, manus and dactylus each bore suckers with distinct morphologies, but the transitions between regions were not distinct, i.e. several suckers of intermediate morphology were present between “typical” manus and “typical” dactylus suckers. A clear terminal pad region was also present. Sucker size was approximately subequal across each transverse row; those in rows 11–15 were largest on the club, and possessed one or two rows of very small, narrow pegs around the aperture, and approximately six very large, conical teeth produced from the distal inner margin of the infundibular ring. As sucker size reduced distally, the size of the teeth also reduced (and their distribution occasionally included the entire inner margin of the sucker ring), while the relative size of the pegs increased. Dactylic suckers were thus characterized by five to seven low, conical teeth on the inner margin of the infundibular ring, with one or two rows of low, round-faced pegs surrounding the aperture proximally and two or three rows distally.

Figures

Figure 6. Tentacle clubs of taoniin species. (A) Helicocranchia cf. pfefferi, ME 38898, mantle length (ML) 12.8 mm; (B) Megalocranchia sp., ME 39935, ML 59.2 mm; (C) Teuthowenia pellucida, ML 39697, ML 28.9 mm. Scale bars = (A) 500 µm, (B) 1 mm, (C) 100 µm.