Liocranchia reinhardti (Steenstrup, 1856)

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 : 1357

Liocranchia reinhardti

( Figure 2B, C ) was the most numerous cranchiid collected (n = 15), and represented the greatest size range (ML 7.7–41.1 mm). The overall morphology of these specimens appeared appropriately intermediate between the smaller and larger specimens figured by Voss (1980: fig. 2). At ML 7.7 mm ( Figure 3B ), the tentacle clubs were stubby, with ~13 transverse rows of four suckers each, following a carpal region of four to six suckers (the latter being present in all specimens examined). The carpal region suckers appeared similar to those of the manus, and manus and dactylus were poorly differentiated, their suckers all appearing similar in size and morphology: the infundibular ring possessed three variably sized, rounded processes distally; a single ring of ovoid to oblong-faced pegs surrounded the aperture; and two to five additional, round-faced pegs were present in a second row distally. At ML 11.2 mm, the clubs were more elongate, and the manus slightly expanded ( Figure 3C ), with ~20 transverse rows of four suckers; manus and dactylus remained poorly differentiated and the suckers appeared similar in morphology across both regions. Each sucker possessed a single row of elongate, polygonalfaced pegs proximally and two to three rows of smaller, ovoid- to circular-faced pegs distally, with the proximal margin of the infundibular ring smooth and the distal margin produced into several low teeth. At ML ~ 40 mm, the carpal suckers were distinct in morphology (orally flattened, with many low, irregular pegs), and the manus remained only slightly expanded ( Figure 3D ), with ~10 rows of four suckers, increasing in size through about the seventh row (with those of the medial series slightly larger than those of the marginal series), thereafter quickly decreasing in size. The dactylus, now well differentiated, comprised a further ~15 rows of suckers, their morphology distinct from those of the manus. Those of the manus possessed one or two rows of small, widely spaced pegs proximally; two or three rows of small, widely spaced pegs distally; and approximately five narrow, pointed teeth around the distal margin of the infundibular ring, with the innermost row of pegs distally also resembling elongate teeth in some suckers. The dactylic suckers possessed smooth inner margins of the infundibular ring, and numerous, densely set pegs, in: two rows proximally, with oral faces of inner row pegs largest, and being elongate polygonal in outline (as in smaller specimens); and four to five rows distally, with circular to ovate oral faces.

Figures

Figure 2. Cranchiin specimens collected by SA MAR-ECO. (A) Cranchia scabra, ME 38828, mantle length (ML) 10 mm. (B, C) Liocranchia reinhardti: (B) ME 39772, ML 9.4 mm; (C) ME 38338, ML 41.1 mm. Scale bars = (A, B) 1 mm, (C) 10 mm.

Figure 3. Tentacle clubs of cranchiin species. (A) Cranchia scabra, ME 38828, mantle length (ML) 10 mm. (B–D) Liocranchia reinhardti: (B) ME 39432, ML 7.7 mm; (C) ME 39772, ML 11.2 mm; (D) ME 38838, ML 41.1 mm. Scale bars = 500 µm.