Prosch, 1849
Slow-moving planktonic and semiplanktonic squids of small to gigantic size. Mantle fused with head and funnel, thin, membranous, semigelatinous or leathery, smooth or bearing small cartilaginous tubercles either circumscribed in some areas or distributed through most of the body. Mantle covered by gelatinous coat in some genera. Fins of very variable form and size, from small petaloid to large lancet-like or round, length up to 60% ML. Head short and narrow. Eyes very large, stalked and tubular in larvae and juveniles of most genera, non-stalked and globular in adults. Two rows of suckers on arms but many rows in median or distal part of some arms in males of some genera; in Mesonychoteuthis part of suckers in mid-parts of arms converted into hooks. Arms with protective membranes and weak keels. Tentacles long, club short, not wide, with 4 rows of denticulate suckers, in 3 genera central suckers converted into hooks. Fixing apparatus well developed, stretched along the stalk. Tentacles autotomized in mature females of most genera. Buccal membrane with 7 lappets, connectives to 4th arms attached ventrally. Gladius thin, rod-like, with diamond-shaped caudal widening (lanceola), in some genera lanceola tapering caudally into a long tail. Rear end of mantle may not reach tail end. Fins attached to rear sides of lanceola, in some genera their anterior ends may reach in front of lanceola on mantle sides. Lanceola reduced in Bathothauma. Funnel valve present or absent. Photophores always present, located usually on ventral side of eyeball, on arm ends (in adult females of some genera), in Megalocranchia also on ventral side of digestive gland. The coelom is very voluminous, closed and filled with a weak solution of NH4Cl, forming a float like in a bathyscaph ("bathyscaphoid squids"). Mantle cavity subdivided by thin horizontal membrane into two chambers, upper (including coelom) and lower, both connected by two round openings over gills. Nidamental glands subdivided into two parts and united with oviductal glands and branchial hearts into one complex on sides of mantle cavity. Larvae with very short arms and long tentacles, usually with characteristic stalked eyes, commonly with ventrally directed rostrum, without photophores. Larval development protracted. Larvae are clear, adults usually purple, brown or yellow, but in some genera transparent. Two subfamilies, 14 genera. Approx. 25 species in the South Atlantic.
Planctonic stages recorded for:
Subfamily Cranchiinae
Cranchia scabra
Liocranchia reinhardti
Leachia atlantica
Subfamily Taoniinae
Helicocranchia pfefferi
Liguriella podophtalma
Sandalops melancholicus
Teuthowenia pellucida
Taonius pavo
Galiteuthis glacialis
Mesonychoteuthis hamiltoni
Megalocranchia oceanica
Egea inermis
Bathothauma lyromma