West-Arctic and East-Arctic distributional ranges of cephalopods

All seven known resident Arctic cephalopods were identified in the collections of the German RV Polarstern (1991, 1993, 1995, 1998) in the waters around Svalbard, northwards from the Kara Sea, in the Laptev and western East Siberian seas: sepia lids Rossia palpebrosa (depths 96–362 m) and R. moelleri (67–101, specimens identified with question mark also at the depths of 38 and 292 m), benthic octopuses Bathypolypus arcticus (180–362 m), Benthoctopus piscatorum (1580–2000 m), and Benthoctopus sibiricus (30m, a juvenile identified with question mark), cirrate octopod Cirroteuthis muelleri (3012–3310 m), and gonatid squid Gonatus fabricii (juveniles: in midwater, 300–500 m, in fish stomachs, 946–990 m). The latter two species are definitely circumpolar and panpolar (inhabiting the whole Polar Basin). The known ranges of R. pulpebrosa, R. moelleri, and B. arcticus are extended from the eastern coasts of Severnaya Zemlya and Vilkitsky Strait to western East Siberian Sea (R. palpebrosa: 150°E) or eastern Laptev Sea (R. moelleri: 130°E, B. arcticus: 135°E), the range of B. piscatorum is extended from West Spitsbergen Island to 91°E. Although gaps still exist in the known distributions of R. palpebrosa. R. moelleri and B. arcticus (these species are considered as West-Arctic or Atlanta-West-Arctic) between the eastern boundaries of their ranges in the Asian Arctic and western boundaries in the Canadian Arctic, there are little doubt that they are in fact circumpolar and widely eurybathic in the western sector of the Arctic but in the eastern sector distributed only at depths > 100–200 m (except R. moelleri: to 67 m). B. piscatorum is known at yet in western Arctic only and may be not circumpolar. Benthoctopus sibiricus is the East-Arctic (definitely not circumpolar) shallow-water benthic octopus having relations with the octopods of northwestern Pacific

Spent females of deep-water squid Gonatopsis octopedatus Sasaki, 1920 (Gonatidae) in the epipelagic layer of the Okhotsk and Japan seas

Four spent females of deep-sea pelagic gonatid squid Gonatopsis octopedatus, dorsal mantle length 24-39 cm, were caught in the 0-50 m layer of the Okhotsk Sea over the depths of 92-126 and approximately 3300 m. Two alike but smaller (12-13.5 cm) females were caught at the surface of the Japan Sea over the depths of 3000-3300 m. They were degenerated, combjelly-like in consistence, most of the arm armature was lost, the oviducts were empty or contained not more than 3-5 eggs up to 4.0-4.3 mm in length. On the contrary, mature males were not degenerated, with most arm hooks and suckers present. The gelatinous degeneration in females begins rather early, at 11 or 111 maturity stages, but at very different sizes. In this period the feeding stops, as degenerated females cannot catch prey. It is supposed that females spawn and juveniles hatch in deep layers, all the eggs are spawned in a short time, and then the females come passively to the surface and die. The difference in size · between females from the two seas may be caused by difference in productivity between very productive Okhotsk Sea and less productive Japan Sea

Redescription of the Deep-Sea Cirrate Octopod Cirroteuthis magna Hoyle, 1885, and Considerations on the Genus Cirroteuthis (Mollusca: Cephalopoda)

31 pages, 29 figures, 4 tables, 1 appendix.The deep-living octopod Cirroteuthis magna Hoyle, 1885 is redescribed, based on the only three specimens known of the species: a mature female (holotype) captured in the south Indian Ocean between Prince Edward and Crozet islands at 2557 m and two specimens, one submature female and one mature male, recently captured in the central Atlantic at 1300 and 3351 m depth, respectively. Video images from the capture of the latter specimen were recorded. This species is characterized by its very great size (to 1300 mm TL), making it the largest known cirrate octopod; butterfly-like shell with open wings; very voluminous eyes with large lenses; arm length 73-79% of the total length; primary web inserted at different levels on the dorsal and ventral ends of the dorso- and ventrolateral arms on both sides, and at the same level on both ends of the dorsal and ventral arms; each arm is independent of the primary web, and is connected with it by a single vertical membrane or intermediate web that is attached along the dorsum of the arm; absence of nodule at the fusion point of both webs. Very large cirri, the first cirri commencing between the 4th and 5th suckers, with three types of suckers on all the arms; cylindro-conical form and those with the acetabulum highly deformable on the first 2/3 of arms and barrel-like on the rest of the arm; absence of particularly enlarged suckers. C. magna is compared with C. muelleri and other related species. Sperm sacs and spermatozoids from C. magna and C. muelleri are described and compared. The Cirroteuthis genus is reviewed and a diagnosis is proposed. This study confirms that the members of the Cirroteuthidae family show several unusual features of great interest.During this study one of the authors (R.V.) was supported by a post-doctoral fellowship from the Spanish Ministery of Education and Science.Peer reviewe

Redescription of the deep-sea cirrate octopod Cirroteuthis magna Hoyle, 1885, and considerations on the Genus Cirroteuthis (Mollusca: Cephalopoda)

The deep-living octopod Cirroteuthis magna Hoyle, 1885 is redescribed, based on the only three specimens known of the species: a mature female (holotype) captured in the south Indian Ocean between Prince Edward and Crozet islands at 2557 m and two specimens, one submature female and one mature male, recently captured in the central Atlantic at 1300 and 3351 m depth, respectively. Video images from the capture of the latter specimen were recorded. This species is characterized by its very great size (to 1300 mm TL), making it the largest known cirrate octopod; butterfly-like shell with open wings ; very voluminous eyes with large lenses; arm length 73–79% of the total length; primary web inserted at different levels on the dorsal and ventral ends of the dorso- and ventrolateral arms on both sides, and at the same level on both ends of the dorsal and ventral arms; each arm is independent of the primary web, and is connected with it by a single vertical membrane or intermediate web that is attached along the dorsum of the arm; absence of nodule at the fusion point of both webs. Very large cirri, the first cirri commencing between the 4th and 5th suckers, with three types of suckers on all the arms; cylindro-conical form and those with the acetabulum highly deformable on the first 2/3 of arms and barrel-like on the rest of the arm; absence of particularly enlarged suckers. C. magna is compared with C. muelleri and other related species. Sperm sacs and spermatozoids from C. magna and C. muelleri are described and compared. The Cirroteuthis genus is reviewed and a diagnosis is proposed. This study confirms that the members of the Cirroteuthidae family show several unusual features of great interest

The cephalopod family Histioteuthidae (Oegopsida): systematics, biology, and biogeography

This study is based on the large, mostly unreported collections of histioteuthids that have accumulated since the family was first revised by Voss in 1969. Of primary importance are the collections made in 1971, 1973, 1975/1976, and 1979 by the R/V Walther Herwig and the R/V Anton Dohrn in the Atlantic and the worldwide collections found in nine Russian or former Russian institutions. An investigation of the food and feeding of large juvenile to adult Histioteuthis celetaria pacifica (G. Voss, 1962) in the western Indian Ocean shows crustaceans and fishes to be the dominant items of prey and of about equal importance in the overall diet. The findings suggest that feeding occurs at approximately equal intensity in the sampled population near the bottom between 364 and 1000 m during both daytime and twilight. Maturity in the histioteuthids is accompanied by marked changes, not only in the genital organs, but also in the arms, especially arms I, which undergo marked secondary, symmetrical modification; in the photophores patterns, particularly on the arms and mantle where unusual, enlarged, darkly pigmented, simple photophores of different sizes and shapes appear in some species; and in the shape of the gladius and mantle in one species. Characters important in distinguishing among taxa include the photophore patterns on the mantle, around the right eyelid and on the arms, the sculpture of the dorsal pad of the funnel organ, the sucker enlargement pattern on the club, the development and structure of the inner web, the number of elements and the attachments of the buccal membrane, the single or double nature of the male genetalia, the internal structure of the spermatophore, the morphologies of the gladius and the lower beak, and the surface morphology of the skin. We recognize 13 species of the family Histioteuthidae in a single genus. Subspecies are recognized in two of the species, Histioteuthis celetaria (G. Voss, 1960) and H. corona (Voss and Voss, 1962), and the available material suggests that more than one taxon is represented in at least two other species, H. reversa (Verrill, 1880) and H. bonnellii (Ferussac, 1834). A key to the species and subspecies is given. Histioteuthis elongata (Voss and Voss, 1962) is the mature stage of H. reversa. The cosmopolitan, warm-water species H. hoylei (Goodrich, 1896), more commonly known in recent literature as H. dofleini (Pfeffer, 1912), comprises two separate, closely related species, H. hoylei in the Pacific and Indian oceans and//, arcturi (Robson, 1948) in the Atlantic. Investigation failed to clearly distinguish the two nominal subspecies of H. bonnellii, H. b. bonnellii and H. b. corpuscula Clarke, 1980, so H. bonnellii is restored, for the time being, to the status of an undivided species with two discrete, ecologically distinct northern and southern populations. A survey of the large new collections of H. meleagroteuthis (Chun, 1910) confirms that//, bruuni N. Voss, 1969, is a variant form of, and synonymous with, the senior species. Five species groups are characterized: the H. reversa species group, comprising H. reversa, H. atlantica (Hoyle, 1885), and H. eltaninae (N. Voss, 1969); the H. hoylei species group, comprising H. hoylei and//, arcturi; the//, bonnellii species group, comprising H. bonnellii and H. macrohista (N. Voss, 1969); the H. Miranda species group, comprising H. miranda (Berry, 1918) and the recently resurrected H. oceani (Robson, 1948); and the H. meleagroteuthis species group, comprising H. meleagroteuthis and H. heteropsis (Berry, 1913). Of the two species not belonging to a currently recognized group, H. corona and H. celetaria, a future, more detailed study than was possible with the available material of H. celetaria will probably result in the elevation of its two subspecies to the specific level, and together they will form the sixth distinct group of closely related species in the family. The distributional patterns nearly equal the number of taxa. The patterns show (1) a close correspondence with patterns of variations in environmental conditions in the oceans; (2) the important role of productivity on the formation of the patterns and in the determination of the abundance of a taxon within its range; and (3) the contiguous nature of the patterns of members of a species group or of subspecies of a polytypic, widespread species. Only three of the eight warm-water species in the family inhabit all three oceans, and of the three cosmopolites, only one is regarded as an undivided species. Of the four species or subdivisions of a species that have Southern Ocean-related patterns, two are typically circumglobal, and two are semicircumglobal. For the latter pair, the broad expanse of low nutrient waters of the central Pacific appears to act as an east-west barrier for dispersal. Although there are no strictly cold-water species or recognized subspecies in the northern hemisphere, two histioteuthids normally extend from warm water into north temperate or subarctic waters in the Atlantic. A tendency for some species or subdivisions of a species to be present in the eastern half of the Atlantic and absent in the western half is shared by both groups. The distributions of the four histioteuthids that are confined to the Pacific appear to be more restricted than are the distributions of purely Atlantic taxa. The differences in the patterns appear to reflect important hydrographical differences between the two oceans