Adinaefiola, 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 : 36-37

Adinaefiola gen. nov.

urn:lsid:zoobank.org:act:D156F532-3035-4FF0-AA5D-3FF6F39D5531

Figs 14–15 (the generic name used in the captions is the former one)

Type species

Sepiola ligulata Naef, 1912 , here designated.

Diagnosis

Sepiolinae with fins rounded; their length about half mantle length. Suckers biseriate on all arms. Tentacle club suckers in 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 present, reduced. Ventral mantle margin with deep funnel indentation and markedly sinuate margin. Hectocotylus (male left arm I) tripartite: basal part either with three suckers, two ventral and one dorsal, or two ventral suckers only; copulatory apparatus with modified suckerless pedicels: two ventral pedicels horn- or tubercle-like, two dorsal pedicels separate from ventral ones, fused with each other and distally directed between the two rows of suckers of distal part, additional dorsal pedicels projecting toward right arm I; distal part with some enlarged suckers in either ventral or both rows. Female bursa copulatrix roughly ear-shaped, devoid of cover.

Included species

Adinaefiola ligulata (Naef, 1912) gen. et comb. nov., A. aurantiaca (Jatta, 1896) gen. et comb. nov. and A. pfefferi (Grimpe, 1921) gen. et comb. nov.

Etymology

This generic name is created to honour the memory of Adolf Naef (1883–1949), founder of modern teuthology and a major scholar of Sepiolinae ; it derives from the combination of Adi, the name that the scientist was called by his family members, with surname, Naef, and the diminutive suffix - iola. Gender feminine.

Discussion of affinities

Adinaefiola gen. nov. fits in the clade of NE Atlantic-Mediterranean Sepiolinae , characterized by the open-type bursa copulatrix and the extant, though reduced, gladius. Its affinities with Sepiola , as understood here, are mainly limited to the same type of light organs, kidney-shaped, and the same type of bursa copulatrix, character state shared by all NE Atlantic-Mediterranean Sepiolinae ( Rondeletiola , Sepietta and Sepiola ). It differs from Sepiola (the genus in which its species were previously placed) in that the modified sucker pedicels in the dorsal row of the copulatory apparatus are separate from the ventral ones. Moreover, the ventral mantle margin is indented and enlarged suckers are also present in the ventral row of the hectocotylus distal part, whereas neither of these two character states occurs in Sepiola s.s.

Remarks

Adinaefiola gen. nov. is established to accommodate the species ligulata, aurantiaca and pfefferi , which should be removed from Sepiola because of their sound differences from the true members of that genus (see above). Adinaefiola aurantiaca gen. et comb. nov. and A. pfefferi gen. et comb. nov. are clearly sister species – the former Mediterranean and the latter from the NE Atlantic (Goud & de Heij 2012) – both of which ostensibly differ from A. ligulata gen. et comb. nov. Nevertheless, the three species in this new genus, in addition to the symplesiomorphic character state ‘dorsal pedicels of copulatory apparatus separate from ventral pedicels’, share a few synapomorphies: the 2 nd and 3 rd modified dorsal pedicels of the hectocotylus are fused with each other and protruding in the middle of the arm; additional modified dorsal pedicels in the copulatory apparatus are separate from the first two, and are mesially directed; and the ventral mantle margin has a deep funnel indentation. In turn, A. aurantiaca and A. pfefferi have a unique muscular ridge projecting laterally from the hectocotylus basal part, which ends in a toothlike structure merging with the ventral pedicels of the copulatory apparatus; this is a synapomorphic character state of the two species.

Figures

Fig. 14. Pair of dorsal arms of Sepiola ligulata Naef, 1912; the hectocotylus is on the right-hand side. The arrow points at the horn-like modified 4th ventral pedicel in the copulatory apparatus (‘‘main tooth’’ of Naef 1923); its point is not visible because hidden by the first ventral sucker of distal part; the 3rd ventral pedicel too, at the base of 4th, is barely visible in this drawing. Abbreviations: S = spatula-like lobe in the copulatory apparatus, formed by 2nd and 3rd modified dorsal pedicels; L = ‘ligula’, the shovellike lobe formed by 4th to 5-6th dorsal pedicels (after Naef 1923, modified).

Fig. 15. Pair of dorsal arms of Sepiola pfefferi Grimpe, 1921; the hectocotylus is on the right-hand side. The letters V indicate the ventral modified pedicels of the copulatory apparatus merging with the muscular ridge (square bracket) arising from the lateral side of basal part (after Goud & de Heij 2012, modified).