Helicocranchia cf. pfefferi, Massy, 1907

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 : 1361

Helicocranchia cf. pfefferi

( Figure 5B) was the second-most numerous cranchiid encountered, represented by nine specimens (ML 8.2–29.0 mm). The minute tentacle clubs ( Figure 6A ) were not well preserved but appeared to have a short carpal region followed by ~11 transverse rows of four suckers, all of similar size across each row, with the diameter of suckers in the third to sixth rows slightly larger than those in the more proximal and distal rows. Sucker morphology appeared consistent overall across rows and along series, with one or two rows of densely set, small circular-tooval faced pegs proximally, and three to four rows distally, with those of the inner row largest; up to six teeth were also observed distally on the infundibular ring. On several suckers, one or more pegs in the inner row appeared abruptly enlarged, and in one instance, several of the distal polygonal platelets and their pegs appeared fused together, while a number of pegs in the outer-most distal row appeared intermediate in morphology between “normal” oval-faced pegs and the elongated, rectangular plates of the outer sucker rim.

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.