Rondeletiola Naef, 1921

Bello, Giambattista, 2020, Evolution of the hectocotylus in Sepiolinae (Cephalopoda: Sepiolidae) and description of four new genera, European Journal of Taxonomy 655 (655), pp. 1-53 : 42

Rondeletiola Naef, 1921

Figs 16–17

Rondeletiola Naef, 1921: 536 .

Type species

Sepietta minor Naef, 1912 , by monotypy.

Diagnosis

Sepiolinae with fins bluntly angled laterally; their length about half mantle length. Suckers biseriate on all arms. Tentacle club suckers in 16 longitudinal rows. Mantle-head occipital band narrow (not reaching over the ocular globes). Ventral mantle margin slightly sinuate, without any deep funnel indentation. Gladius absent. Unpaired visceral photophore on ventral surface of ink sac, slightly oval, clearly derived from paired light organs joined in sagittal plane. Hectocotylus (male left arm I) tripartite: basal part with three suckers, two ventral and one dorsal; copulatory apparatus with transverse formation of two ventral and two dorsal modified suckerless pedicels all four of them fused at their bases, ventral-most strongly developed hook-like, others hardly developed, dorsal pedicels forming most part of transverse crest; distal part lacking first two ventral suckers, some proximal suckers enlarged in both rows. Female bursa copulatrix roughly ear-shaped, devoid of cover.

Included species

Rondeletiola minor (Naef, 1912) and R. capensis (Voss, 1962) .

Remarks

This genus is widely distributed from the NE Atlantic and Mediterranean, throughout the E Atlantic, to the South African part of the Indian Ocean. It is characterized among the sepiolines of this area by its unique visceral light organ, that differs from that of Boletzkyola gen. nov. (compare with the description of the latter genus). Rondeletiola is sister genus to Sepietta (Bello 1998) . The species Inioteuthis capensis is re-assigned to Rondeletiola fide Vecchione & Young (2004) and Reid (pers. com.).

Figures

Fig. 16. Pair of dorsal arms of Rondeletiola minor (Naef, 1912) oral view; the hectocotylus is on the right side; a, b, c, d indicate the 4th ventral, 3rd ventral, 2nd dorsal, 3rd dorsal modified pedicels, respectively, forming the copulatory apparatus. Scale bar: 1 mm.

Fig. 17. Visceral light organ of Rondeletiola minor (Naef, 1912) (the hole in the membrane above the light organ was accidental). Scale bar: 0.5 mm.