ALBERT

Description: Massive microbial mats covering up to 4-meter-high carbonate buildups prosper at methane seeps in anoxic waters of the northwestern Black Sea shelf. Strong 13C depletions indicate an incorporation of methane carbon into carbonates, bulk biomass, and specific lipids. The mats mainly consist of densely aggregated archaea (phylogenetic ANME-1 cluster) and sulfate-reducing bacteria (Desulfosarcina/Desulfococcusgroup). If incubated in vitro, these mats perform anaerobic oxidation of methane coupled to sulfate reduction. Obviously, anaerobic microbial consortia can generate both carbonate precipitation and substantial biomass accumulation, which has implications for our understanding of carbon cycling during earlier periods of Earth's history.

Description: Study of Nautilus belauensis i its natural habitat in Palau, West Caroline Islands, shows that growth is slow (0.1 millimeter of shell per day on the average) and decreases as maturity is approached and that individuals may live at least 4 years beyond maturity. Age estimates for seven animals marked and recaptured between 45 and 355 days after release range from 14.5 to 17.2 years. These data indicate that the life-span of Nautilus may exceed 20 years and that its life strategy is very different from that of other living cephalopods.

Description: The species of squid referred to as Loligo brasiliensis Blainville, 1823 by Castellanos and Cazzaniga (1979) is shown to be Loligo sanpaulensis (Brakoniecki, 1984). The name Loligo brasiliensis is shown to be a nomen dubium. Loligo gahi d'Orbigny, 1835 and L. sanpaulensis are redescribed and illustrated. Loligo patagonica Smith, 1881 is shown to be a synonym of L. gahi. Loligo ellipsura Hoyle, 1885 is shown to be a nomen dubium. The distribution and identification of Loligo sanpau/ensis and L. gahi are discussed.

Description: Trophic relations of cephalopods in southern Brazil were investigated from predation on cephalopods by 71 species of potential predators, including two squids, 47 fishes, seven seabirds and 15 marine mammals from shelf, upper slope and oceanic adjacent waters. In all, 27 families and 41 species of cephalopods were identified from stomach contents. The number of families ranged from six, in the diet of shelf predators, to 27 families in those from upper slope and adjacent oceanic waters. The most frequent cephalopod prey on the shelf was Loligo sanpaulensis, particularly important in the diet of Franciscana dolphin Pontoporia blainvillei, occurring also in the diet of the penguin Spheniscus magellanicus, the fur seals Arctocephalus australis, A. gazella, A. tropicalis, and several benthic and demersal fishes. Ommastrephidae, mainly Illex argentinus and Ornithoteuthis antillarum, was the most frequent family in the diet of predators from upper slope and adjacent oceanic waters. Illex argentinus was an important prey for the wreckfish Polyprion americanus, the bigeye tuna Thunnus obesus, the swordfish Xiphias gladius and some marine mammals, especially in their winter and spring northward reproductive migration. Ornithoteuthis antillarum was frequent in the diet of the skipjack tuna Katsuwonus pelamis, the albacore Thunnus alalunga, the yellowfin tuna T. albacares, the Atlantic sailfish Istiophorus albicans and the white marlin Tetrapturus albidus. Ammoniacal squids, such as Ancistrocheirus lesueurii, Histioteuthis spp, Chiroteuthis veranii and Octopoteuthis sp, were mainly found in stomach contents of the blue shark, Prionace glauca, the pygmy sperm whale Kogia breviceps, the dwarf sperm whale K. sima, the long-finned pilot whale, Globicephala melas and oceanic seabirds. The relative importance, based on frequency of occurrence, of cephalopods as food resources seems to be higher in the food chains of the upper slope and adjacent oceanic waters, when compared to the continental shelf.

Description: The manned submersible Johnson Sea-Link II was used for a series of dives on the continental slope of the eastern Gulf of Mexico in September 1995. The deep-sea squids Mastigoteuthis hjorti Chun, 1913 and Octopoteuthis megaptera (Verrill, 1885) were repeatedly observed at depths of 600–850 m. Both species were videotaped alive, in situ, for the first time during these dives. These species share the characteristic of very large fins, almost as long as the mantle length, but their swimming behavior observed in the vicinity of the submersible differed greatly. Throughout most of the videotaped sequences of O. megaptera, it swam with its body oriented obliquely with the head upward, arms flexed laterally and dorsally. The fins flapped in the arc between overlapping ventrally and extending laterally, never traversing dorsally above the body plane. Conversely, the near-bottom observations of M. hjorti showed it to behave similarly to previous descriptions of Mastigoteuthis magna, orienting vertically with the head down and tentacles extended to the sediment. This orientation is maintained by gentle, complex undulation of the fins. A third species with very large fins and extremely long arms was observed near the bottom from an ROV at approximately 2200 m in January 2000. While it differed from any previously known family, it behaved similarly to a mastigoteuthid. We now believe this specimen was a 'big-fin', family Magnapinnidae Vecchione and Young, 1998. If so, this observation and a similar squid recently observed and video-taped from a submersible in the Indian Ocean extend the known distribution of the recently discovered family to deep waters in subtropical areas around the globe.

Description: The midwater fauna off Nova Scotia was sampled with large pelagic trawls over bottom depths of 169–4800 m on seven cruises between August 1986 and June 1989. We identified, counted, and measured mantle length (ML) of all 3661 cephalopods collected on these cruises. These specimens comprised about 63 species in 28 families. The ten most abundant families were (in rank order) Ommastrephidae, Enoploteuthidae, Pyroteuthidae, Histioteuthidae, Brachioteuthidae, Cranchiidae, Mastigoteuthidae, Octopoteuthidae, Onychoteuthidae, and Alloposidae. Although Illex illecebrosus was the most numerous species (1156 specimens in 54 samples), Abraliopsis hoylei (679 in 90, respectively), Histioteuthis reversa (164 in 72), and Pterygioteuthis gemmata (327 in 69) were collected more frequently. Large squids collected here include 3 cranchiids, Teuthowenia megalops (max. ML = 370 mm), Galiteuthis armata (308 mm), and Taonius pavo (300 mm), as well as mature female Gonatus fabricii (275 mm) and Illex illecebrosus (235 mm). Among the 47 species with 〈10 specimens, noteworthy examples include Chiroteuthis joubini, Chiroteuthis capensis, Joubiniteuthis portieri, Histioteuthis meleagroteuthis, Pholidoteuthis boschmai, Lepidoteuthis grimaldi, Heteroteuthis dispar, Vampyroteuthis infernalis, and Stauroteuthis syrtensis.

Description: The cephalopod fauna off the off Adang-Rawi Archipelago, Thailand, and adjacent areas, was investigated between December 1998 and April 1999 during the northeast monsoon season. Four families of cephalopods were found, namely Loliginidae (Loligo duvauceli, L. chinensis, Loliolus sumatrensis and Sepioteuthis lessoniana), Sepiidae (Sepiella inermis, Sepia aculeata, S. pharaonis, S. lysidas, S. brevimana and S. recurvirostra), Sepiolidae (Euprymna stenodactyla), and Octopodidae (Octopus spp.). The average catch rate and biomass were 4.34 kg h−1 and 320.66 t, respectively. The highest catches were in February (5.32 kg h−1; 382.57 t), December (4.10 kg h−1; 314.33 t) and April (3.61 kg h−1; 265.07 t). Diversity measures were applied and three assemblages recognized, i.e., the western side of Tarutao Island, north and south of Adang-Rawi Archipelago. Salinity was the best-fitting environmental parameter and correlated with biotic pattern in the survey area.

Description: The gills of cirrate octopods are known to be unusual with terms 'half orange' and 'sepioid' commonly used to describe them. The structure and relationships of these gills to other cephalopod gills have not been adequately investigated. In this paper we investigate the evolution of the gills of cirrates and of octopodiforms in general. Octopodiform gills differ from the primitive cephalopod gill, as exemplified by the gills of Nautilus and decapodiforms, by the presence of septa along the axes of the primary and secondary lamellae. The septa apparently constrain the respiratory surfaces to form tree-like folds rather than the fan-like folds of other cephalopods. In members of the Vampyromorpha, the sister taxon of the Octopoda, gills have a peculiar circulation pattern that seems to be a unique adaptation to its deep-sea habitat. The arrangement of blood vessels in the cirrates involves the repositioning of the primary efferent vessels deep within the gill. In addition, an axial anastomosis of superficial afferent vessels resulted in an appearance similar to a decapodiform gill but with afferent rather than efferent vessels on the 'top' of the gill. This, combined with the lack of a branchial canal and the presence of bilaterally symmetrical lamellae, has resulted in the appearance of a 'sepioid' gill. The 'half-orange' gill appears to result from a foreshortening and rotation of the gill to give the impression of a nearly radial arrangement of equal-sized primary lamellae rather than the typical serial arrangement of primary lamellae that decrease in size distally. Apparently, the adaptations of the octopodiform gill resulted from a need to increase the efficiency of oxygen uptake. We suggest that a major factor in the evolution of the Octopodiformes was the adaptation to a habitat low in oxygen.

Description: Small benthic octopodids of the genus Pareledone are commonly found around the shelf area of the sub-Antarctic island South Georgia but little is known about their biology. During three consecutive groundfish surveys in January–February 1994, September 1997 and January 2000, a total of 894 Pareledone spp. were caught in demersal trawl samples at depths of 107–440 m. Pareledone turqueti was the more abundant species and was found across the entire survey area around Shag Rocks and South Georgia, whereas P. polymorpha was absent from the Shag Rocks area in 1994 and only single specimens were obtained in the subsequent surveys. In addition, five specimens of the rare octopodid Thaumeledone gunteri were caught from a deeper station (〉350 m depth). The geographic and bathymetric distributions of these three species are discussed as is their reproductive biology.

Description: The systematics of the deep-sea cirrate octopod genus Opisthoteuthis Verrill in the Atlantic Ocean is reviewed. Comparisons, based on examination of all extant type material and new, reported and unreported material collected in recent years from the Atlantic, show the presence of five species: Opisthoteuthis agassizii Verrill 1883, O. grimaldii (Joubin, 1903), O. massyae (Grimpe, 1920) and two new species, O. calypso and O. hardyi, which are described. Opisthoteuthis agassizii, distributed only in the western North Atlantic, is redescribed, and a neotype is designated for the presumed lost holotype. Opisthoteuthis grimaldii, distributed in the East Atlantic and possibly also in the western North Atlantic, and O. massyae, distributed in the East Atlantic are also redescribed and junior synonyms listed. Opisthoteuthis calypso, found in the East Atlantic and O. hardyi, known only from a single specimen from the SW Atlantic are described. New morphometric data for O. agassizii, O. massyae and O. grimaldii are given. Illustrations, geographical distributions and a review of the biological information for all five species are provided.

Description: Light organ development was studied in the sepiolid squid Sepiola robusta Naef and compared to that of Euprymna scolopes Berry. Both species form obligate mutualisms with luminous bacteria from the environment. The embryonic period of S. robusta, which is at least double to that of E. scolopes at similar temperatures, produced additional features not reported to occur in the E. scolopes light organ, including an extended ciliated ridge at the base of the light organ, as well as additional crypt spaces to house symbiotic bacteria. Accessory structures, which are used to modify the bacteria-produced light, are not under the induction of symbiotic bacteria and appear in S. robusta before hatching, whereas in E. scolopes these tissues form post-hatching. At hatching the light organs of both species respond to symbiotically competent bacteria and undergo similar developmental remodeling. Specifically, the ciliated epithelial fields on the surface of the light organ undergo a program of cell death and regression that spans 4 to 5 d in E. scolopes, and over 9 d in S. robusta. Although the timing of embryogenesis differs between these two species, the results of these studies demonstrate that the influence of Vibrio fischeri, the specific symbiont, appears to be restricted to the initial stages of post-hatching development of both light organs.

Description: Atlantic climate variability is an important driving force of climate in the surrounding land areas. In his Perspective, Visbeck explores recent advances toward understanding and predicting climate variability in the tropical Atlantic and the North Atlantic, and elucidating the role played by the ocean's circulation.