Lusepiola, Bello, 2020

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 : 41

Lusepiola gen. nov.

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Figs 8A , 13 (the generic name used in the captions is the former one)

Type species

Sepiola birostrata Sasaki, 1918 , here designated.

Diagnosis

Sepiolinae with fins rounded with large anterior lobe, which may reach the anterior mantle margin; their length about ½ to ¾ mantle length. Suckers biseriate on all arms. Tentacle club suckers in 4 to 8 longitudinal rows. Mantle-head occipital band narrow (not reaching over the ocular globes). A pair of kidney-shaped photophores on ventral surface of ink sac. Gladius absent. Ventral mantle margin slightly sinuate, without any deep funnel indentation. Hectocotylus (male left arm I) tripartite: basal part with four regular suckers in two rows; copulatory apparatus with modified sucker-less pedicels: two ventral pedicels horn-like, aligned, directed distally and slightly laterally, and two dorsal pedicels flattened, fused with each other and directed ventrally, adhering to the oral arm surface and to the base of both ventral horns to form a concave pad; distal part with sucker pedicels of both rows leaf-like, lengthened, widened, triangular- or squarish-shaped, flattened promixo-distally, their bases inserted transversally on arm oral surface, except for distalmost suckers with regular short pedicels; in several preserved specimens distal part rotated towards right dorsal arm. Female bursa copulatrix pouch-like.

Included species

Lusepiola birostrata (Sasaki, 1918) gen. et comb. nov. and L. trirostrata (Voss, 1962) gen. et comb. nov.

Etymology

This genus is dedicated to Chung Cheng Lu (Museum of Victoria, Melbourne, Australia and National Chung Hsing University, Taichung, Taiwan), in recognition of his enormous contribution to teuthology, including Sepiolinae systematics; its name derives from the combination of Lu’s family name with Sepiola , a closely related genus. Gender feminine.

Discussion of affinities

Lusepiola gen. nov., Euprymna , Eumandya gen. nov. and Boletzkyola gen. nov. all possess a closed bursa copularix, a clear indication of their affinity. However, Lusepiola gen. nov. differs from the other three genera because the formation of its hectocotylus copulatory apparatus involves modified sucker pedicels from both the ventral and dorsal rows. It differs from Sepiola s.s., from which its species were removed, primarily because of the different type of bursa copulatrix; moreover, the basal part of its hectocotylus bears four suckers (two complete rows) instead of three. The peculiarly modified pedicels in the distal part of the hectocotylus separates Lusepiola gen. nov. from all other sepioline genera.

Remarks

The species in this genus, namely L. birostrata gen. et comb. nov. and L. trirostrata gen. et comb. nov., are distributed in the western Pacific from the Okhotsk Sea to Singapore (Reid & Jereb 2005; Okutani 2015).

Figures

Fig. 8. Basic types of bursae copulatrices in Sepiolinae Leach, 1817 (highlighted by white frames). A. Closed type, plesiomorphic condition; mated female displaying a bunch of spermatophores inserted in the bursa copulatrix and peeping out its opening (arrow) (Sepiola birostrata Sasaki, 1918). B. Open type, apomorphic condition; virgin female (Sepiola boletzkyi Bello & Salman 2015). Scale bars: 1 mm.

Fig. 13. Hectocotylus of Sepiola birostrata Sasaki, 1918. A. The square bracket indicates the two hornlike modified ventral pedicels of the copulatory apparatus; the curved line encompasses the flattened modified dorsal pedicels of the copulatory apparatus and the arrow points at the hollow left by a reduced sucker. In the distal part, several leafy pedicels bearing regular suckers are visible. B. Detail of the ventral row of vestigial suckers, encompassed by the square bracket; below it, the point of the copulatory apparatus distal horn is visible; to the left side, several leaf-like pedicels of the distal part are evident. Scale bars: A = 1 mm; B = 0.5 mm.