(Degner, 1925)
Mantle of leathery consistence in juveniles, gelatinous in adults, almost transparent, cylindrical in anterior and narrowly-conical in posterior half, acuminate to needle-shaped posteriorly. On anterior-ventral side of mantle 2 parallel straight hyaline stripes, bearing cartilaginous tubercles, their length approx. 14-15% ML; with 7-8 large multifid rosette-shaped tubercles, approx. 5 small multifid ones, and some simple conical between the large ones. Second large tubercle from anterior end not displaced laterally. Head narrow, with rather long "snout" (arm-crown pillar) in larvae. Eyes in larvae and juveniles stalked, with short rostrum (slipper-shaped), in adults not stalked. Fins in larvae petaloid, in adults transversely-oval, not extending beyond mantle. Anterior margin of fin arcuate, posterior almost straight, its maximum width behind the middle. Fin width 1.3-1.6 times fin length. 3rd arms long, others rather short. Tentacles long, fixing apparatus stretched along stalk, club with 4 rows of suckers, of which the 4-5 central pairs are enlarged. Funnel valve absent. 6 oval eye photophores: 1 near pupil, 6 in an arc on ventral side. Large elongate photophore on ends of 3rd arms in maturing and mature females. In males right 4th arm hectocotylized and midportions of all other arms modified (suckers enlarged, with reduced apertures). Squids semitransparent with only some dispersed large dark chromatophores. ML up to 10 cm.
Larvae distinguishable by tubercles on anterior-ventral hyaline stripes (developed at ML approx. 7 mm), cylindrical mantle, and stalked eyes, but species characters not distinguishable before late juvenile stage. First eyeball photophores developed at ML <3 cm, full pattern of photophores and reduction of eyestalks at >5 cm.
The system of the genus Leachia remains unclear, the number of species and their distribution unknown. Supposedly 5-6 species in the South Atlantic, some in tropical-subtropical, others in southern subtropical and southern peripheral areas.