Identification, distribution and relative abundance of paralarval gonatid squids (Cephalopoda: Oegopsida: Gonatidae) from the Gulf of Alaska, 2001 2003

Paralarvae of the family Gonatidae were sampled in the Gulfof Alaska during spring 2001–2003. Taxonomic characterswere determined to allow identification of the specimens tospecies. The dorsal head chromatophore pattern (DHCP) was themost robust character and allowed identification to speciesfor the first time without requiring the removal and examinationof the radula. Six different DHCPs were found among the sixspecies in the study area. The 1140 specimens collected consistedof the following six species: Berryteuthis anonychus (759),Berryteuthis magister (71), Gonatopsis borealis (155), Gonatuskamtschaticus (1), Gonatus madokai (4) and Gonatus onyx (143).The specimens had a size range of 3.0–20.63 mm dorsalmantle length with the majority of specimens smaller than 10 mm.All species showed an increasing trend in abundance from theshelf (0–200 m) to the slope (200–1000 m)to the basin (>1000 m) except G. onyx in 2001 and 2002.Wide variation in distribution and abundance was found for thefour most abundant species; however, in general, B. anonychuswas most abundant and widely distributed, followed by Gonatopisborealis, Gonatus onyx and B. magister. (Received 28 April 2006; accepted 1 February 2007)     

Short communication. Statolith microstructure from hatchlings of the oceanic squid, Gonatus onyx (Cephalopoda, Gonatidae) from the Northeast Pacific

Statolith microstructure was studied in hatchlings of deepwater-spawned gonatid squid Gonatus onyx, caught between 1350 and 1420 m over a bottom depth of 2100 m in the San Clemente Basin off San Diego, California. It was found that the shape and size of the hatchling statolith were similar to those of the first-check statolith observed in paralarvae and small juveniles of G.onyx. The inner part of the bipartite postnuclear zone (= first-check statolith) is formed during late embryo-genesis, and the first check within the statolith microstructure must be considered as a starting point of increment counting for age estimation of Gonatus spp.      

Species-specific differences in the substrate-inhibitory specificity of cholinesterases from optical ganglia of squids of the Gonatidae family

A comparative study was carried out of the substrate and inhibitory specificity of cholinesterase preparations from squids, representatives of 3 genes and 5 species of the Gonatidae family:Berryteuthis (B. magister andB. anonichos),Gonatus (G. kamtschaticus andG. tinro), andGonatipsis (G. borealis), that have overlapping habitation areals in the Bering Sea. As substrates, there were used bromides of acetylthiocholine, propionylthiocholine, and butyrylthiocholine, as organophosphorus inhibitors, diisopropylfluorophosphate, a cation-containing inhibitor, and 4 hydrophobic compounds. The homogeneity of the cholinesterase activity in these preparations has been shown, the intergenus and interspecies differences in the enzyme properties are revealed, and also the peculiarity of properties of enzymes from Gonatidae squids is emphasized in comparison with cholinesterase from the Pacific squidTodarodes paciflcus and “standard” mammalian enzymes (from human erythrocytes and horse blood serum). The revealed interspecies differences are discussed in terms of evolutionary development of the Gonatidae family.     

Feeding habits of the blue shark, Prionace glauca, and salmon shark, Lamna ditropis, in the transition region of the Western North Pacific

We describe the feeding habits of 70 blue sharks (Prionace glauca) and 39 salmon sharks (Lamna ditropis) caught at 0–7 m depth at night by research drift gillnets in the transition region of the western North Pacific during April–May of 1999 and 2000. Blue sharks of 50–175 cm total length fed on a large variety of prey species, consisting of 24 species of cephalopods and 16 species of fishes. Salmon sharks of 69–157 cm total length fed on a few prey species, consisting of 10 species of cephalopods and one species of fish. Important prey for the blue sharks were large, non-active, gelatinous, meso- to bathypelagic cephalopods (e.g., Chiroteuthis calyx, Haliphron atlanticus, Histioteuthis dofleini and Belonella borealis) and small myctophid fishes. Important prey for the salmon sharks were mid-sized, active, muscular, epi- to mesopelagic squids (e.g. Gonatopsis borealis, Onychoteuthis borealijaponica and Berryteuthis anonychus). Our results suggest that blue sharks feed on cephalopods mainly during the daytime when they descend to deep water. Salmon sharks may feed opportunistically with no apparent diurnal feeding period. Blue sharks and salmon sharks have sympatric distribution in the transition region in spring; they have different feeding habits and strategies that reduce competition for food resources.     

Subtropical migrants in the southwestern part of the Bering Sea

From 2003 to 2008, arrivals (including mass) of sea bream Brama japonica, saury Cololabis saira, and spiny dogfish Squalus acanthias, as well as some cases of catches of Japanese anchovy Engraulis japonicus, and Todarodes pacificus, and Onychoteuthis borealijaponica squids were recorded in Pacific waters of Kamchatka in the southwestern sector of the Bering Sea. The penetration of these species far to the north is related to feeding migrations as well as to the passive transfer of water by currents. Migrations of subtropical species to Pacific waters of Kamchatka and the southern part of the Bering Sea depend on thermal conditions and circulation of currents in each particular year and are determined, first of all, by the intensity of the Western Subarctic gyre, although in some years, the migration flow of B. japonica and C. saira from the northeastern part of the Pacific Ocean increases.     

Cookie-cutter shark <Emphasis Type="Italic">Isistius brasiliensis</Emphasis> eats Bryde’s whale <Emphasis Type="Italic">Balaenoptera brydei</Emphasis>

We examined the stomach contents of cookie-cutter sharks, Isistius brasiliensis, collected by drift-net surveys in the western North Pacific in the early summer. The stomachs contained fresh flesh plugs and cephalopod beaks. Approximately half of the flesh plugs were identified as Bryde’s whale, Balaenoptera brydei, based on genetic analysis, and several of the lower beaks were identified as boreal clubhook squid, Onychoteuthis borealijaponica. The range of estimated dorsal mantle lengths for the squids was 60–172 mm. These results are evidence of predation by of cookie-cutter sharks on cetaceans and of an overlap in the vertical distribution of both species.     

A comparative study of the cephalopod prey of Patagonian toothfish (<Emphasis Type="Italic">Dissostichus eleginoides</Emphasis>) and southern elephant seals (<Emphasis Type="Italic">Mirounga leonina</Emphasis>) near Macquarie Island

Within the Southern Ocean, Patagonian toothfish (Dissostichus eleginoides Smitt) and southern elephant seals (Mirounga leonina Linnaeus) forage mainly on fish and cephalopods. From what is known of their diets, the proportion of fish is greatest in toothfish diet. When foraging at-sea for squid, elephant seals and toothfish most often co-occur over continental shelves and submarine plateaux surrounding sub-Antarctic land masses within the Southern Ocean. I used traditional (non-molecular) techniques to compare the squid diet of these two predators. Of the 21 squid species identified, 10 were common to the diets of both predators. One species, Gonatus antarcticus, dominated (61%) the biomass of squid consumed by toothfish, but was of little importance to the elephant seals (2.3%). By contrast, Martialia hyadesi was the most important single species to the elephant seals diet (29%), but it contributed 1% to the toothfish diet. Onychoteuthids (Kondakovia longimana, Moroteuthis ingens and Morotenthis knipovitchi) were important to both predators diets. The median sizes of five cephalopod species (Slosarczykovia circumantarctica, Galiteuthis glacialis, Gonatus antarcticus, Moroteuthis ingens and Moroteuthis knipovitchi) which were common to both the seal and toothfish diets, were significantly larger in the toothfish stomachs than in the elephant-seal stomachs. Percent similarity indices for the squids that overlapped both diets were in some cases as high as 100%. However, after between-species differences in prey size consumption were accounted for, the similarities fell to between 20 and 50%. These results indicate that the strength of the trophic interaction between the seals and the fish might be weaker than previously thought. The consumption of significantly different-sized squid can also be used to suggest spatial (vertical) foraging separation of these two predators because there is evidence for ontogenetic change in the size of squid species with depth; older, and thus larger, squids live deeper than smaller individuals of the same species.     

The Seasonal Dynamics of the Abundance and Species Composition of Nekton in the Upper Epipelagic Layer of the Western Bering Sea

The western Bering Sea is an important region that is used by many nekton species for feeding. From the seasonal aspect, these waters are characterized by pronounced dynamics of the abundance and structure of the nekton community. The pattern of seasonal variations in the total biomass, composition, and structure of nekton in the upper epipelagic layer (0–50 m) of this region are considered based on the data of the complex studies conducted by the Pacific Research Fisheries Center (TINRO Center) in the deep-sea basins of the western Bering Sea and the Navarin area in June–October, 2003–2015. During June–October, the total nekton biomass changed by more than an order of magnitude: from 100 kg/km² in early June it increased to a maximum of 2700 kg/km² in the middle of August and then declined significantly, to 200 kg/km², in late October. The major contribution to the nekton biomass was made by Pacific salmon (Oncorhynchus spp.), mainly O. keta, as well as by the boreopacific gonate squid (Boreoteuthis borealis) and the shortarm gonate squid (Gonatus kamtschaticus). As well, walleye pollock (Theragra chalcogramma), Pacific herring (Clupea pallasii), and capelin (Mallotus villosus) were abundant in waters near the shelf. The dynamics of the species structure can be divided into three periods: (1) early summer, from June to the second 10 days of July, when pre-anadromous pink (O. gorbuscha) and chum salmon predominate and the species diversity is at a medium level (the polydominance index is 3.5–4.0); (2) summer, from the third 10 days of July to the second 10 days of September, when chum salmon becomes dominant (more than 70% of the biomass) and the species diversity is at a minimum (1.5–2.0); and (3) autumn, from the third 10 days of September to October, when common species such as chum salmon, sockeye salmon, and boreopacific gonate squid have relatively equal proportions, the proportion of pink salmon underyearlings is also high, and the species diversity is at a maximum (4.5). The pattern of the spatial distribution in the early summer period is characterized by active formation of the nekton community due to the large-scale migrations from the central and eastern Bering Sea and from the Pacific Ocean. In the summer period, the concentration of the nekton in the western Bering Sea, particularly in the Aleutian Basin, reaches the maximum level and the migratory activity decreases. Reverse migration processes are observed in the autumn period: a major portion of the nekton biomass redistributes to the southeastern Commander Basin for further movement to the ocean and the central Bering Sea.     

New information on the life history of cephalopods off west Greenland

We examined 323 cephalopods collected by bottom trawl from depths between 162 and 536 m near Disko island, West Greenland. The most abundant species were the boreoatlantic armhook squid Gonatus fabricii, the sepiolid Rossia moelleri and the spoonarm octopus Bathypolypus arcticus. From this sampling we provide new information on the population structure, bathymetric distribution and the reproductive biology of cephalopods from this area. Special emphasis is given to the sepiolid R. moelleri, for which the life cycle is proposed. Further, this study provides new relationships of beak size to mantle length and wet body mass for G. fabricii, R. moelleri and B. arcticus.     

Elemental distribution in cephalopod statoliths: NanoSIMS provides new insights into nano-scale structure

We have applied the novel analytical method NanoSIMS to cephalopod statoliths for the first time in order to analyse their chemical microstructure, using a spatial resolution of 400 nm. This technique makes it possible to analyse in situ nano-scale chemical variations between increment layers. In statoliths of the boreoatlantic armhook squid Gonatus fabricii, we found distinct concentration patterns indicating a periodicity in strontium and sodium distributions. Sr and Na show a negative relation, both elements showing alternating patterns where the increments vary in width between approximately 1 and 5 μm. Results suggest, that aragonite deposited during the night is rich in Na and poor in Sr, while aragonite deposited during the day is rich in Sr and poor in Na. This study demonstrates the excellent suitability of NanoSIMS for nano-scale microchemical analyses of aragonite, providing new information on calcification processes and individual life histories. Possible future fields of application include not only cephalopod statoliths, but also virtually all biomineralized tissues in aquatic organisms like fish otoliths, gastropod statoliths, bivalve shells, foraminifers and corals.     

Cephalopod remains from stomachs of sperm whales (Physeter macrocephalus) that mass‐stranded along the Oregon coast

On 16 June 1979, a herd of 41 sperm whales stranded near the mouth of the Siuslaw River in Florence, Oregon. The stomach contents from 32 whales were collected, identified to the lowest taxonomic level possible, enumerated, and measured. A total of 20,247 cephalopod lower beaks that represented 24 species from 14 different families were recovered. The most numerous species were Histioteuthis hoylei (25.9%), Taonius borealis (12.9%), Galiteuthis phyllura (11.2%), Gonatopsis/Berryteuthis type (10.9%), and Moroteuthis robusta (10.7%). Reconstructed estimates of mass indicated that M. robusta contributed almost 50% of the total mass of cephalopods consumed, followed by H. hoylei (19.3%), and T. borealis (7.0%). The most important species in the diet of stranded whales were M. robusta, H. hoylei, T. borealis, G. phyllura, Octopoteuthis deletron, and Gonatopsis/Berryteuthis type. There were significant differences in the diet of males and females, but no differences between sperm whales of different age groups. Overall, sperm whales primarily consumed small cephalopods that were likely eaten south of 45ºN in or near the California Current System. This study provides new estimates of the food habits of sperm whales in the northeast Pacific from one of the largest strandings of this species.     

Comparative study of substrate and inhibitory specificity of monoamine oxidase of squid optic ganglia

Comparative study of substrate specificity of monoamine oxidase (MAO) of optic ganglia of the Pacific squid Todarodes pacificus and the Commander squid Berryteuthis magister has been carried out. The enzyme of the Pacific squid, unlike that of the Commander squid, has been established to be able to deaminate not only tyramine, tryptamine, serotonin, benzylamine, and β-phenylethylamine, but also histamine-substrate of diamine oxidase (DAO). In relation to all studied substrates, the MAO activity of optic ganglia of T. pacificus is several times higher as compared with that of B. magister. In the case of deamination of serotonin this difference was the highest and amounted to 5 times. Semicarbazide, the classic DAO inhibitor, at a concentration of 10 mM did not inhibit catalytic activity of both studied enzymes. The substrate-inhibitory analysis with use of deprenyl and clorgyline, specific inhibitors of different MAO forms, indicates homogeneity of the enzyme of the Pacific squid and heterogeneity of the Commander squid enzyme whose composition seems to contain at least two MAO forms. There are obtained quantitative differences in substrate specificity and reaction capability with respect to the inhibitors clorgylin and deprenyl for MAO of optic ganglia of the studied squid species. These differences probably can be explained by significant differences in the evolutionary level of these biological species.     

Comparative analysis of sensitivity of cholinesterases to reversible inhibitors by methods of multidimensional statistics

Using the methods of factor and cluster analysis, the statistical treatment is performed of data on interaction of seven cholinesterases (ChE)—human acetylcholinesterase, horse butyrylcholinesterase, cholinesterases of frog brain and of different squid species (Todarodes pacificus and Berrytheutis magister, in the latter case, individuals from three different habitats are compared)—with 141 reversible inhibitors of various structures. Statistically significant differences between ChE of squids and vertebrates are shown. The previously revealed intraspecies peculiarities of ChE in the Commander squid B. magister are statistically confirmed.     

First report on the stomach contents of long‐finned pilot whales,Globicephala melas,stranded in New Zealand

Abstract

Stomach contents of the long‐finned pilot whale, Globicephala melas, are reported for the first time from New Zealand waters. Analyses based on two male and three female whales (2.5–5.3 m in length) that stranded on Farewell Spit, Golden Bay, South Island in December 2005 revealed a diet comprised exclusively of cephalopods (2-33 lower cephalopod beaks per stomach). Two genera of cephalopod from two orders; arrow squid, Nototodarus spp. (Teuthoidea: Ommastrephidae), and common octopus, Pinnoctopus cordiformis (Octopoda: Octopodidae) were represented. A further five pilot whale stomachs were examined and found to be empty.     

Cephalopod diversity in commercial fisheries landings of New South Wales, Australia

The development of commercial cephalopod fisheries is a relatively recent phenomenon in Australia. Multiple commercial fisheries land cephalopods in New South Wales (NSW), Australia, yet few useful data exist for the sustainable management of these resources. This paper presents results of the first study to quantitatively document cephalopod diversity in commercial fisheries landings of NSW. A total of 21 cephalopod taxa were observed in randomly selected market samples from the three major regions of landings. Few species comprised the majority of landings in each market category, but several species constituted the remaining proportions. Sepia rozella and S. hedleyi comprised the largest proportion by numbers and weight in cuttlefish samples. Octopus australis and O. tetricus were most abundant in octopus samples, while Sepioteuthis australis, Nototodarus gouldi, and Uroteuthis (Photololigo) sp. comprised the largest proportion of squid samples. The proportion each species contributes to commercial cephalopod landings reported at the Sydney Fish Market was estimated. Cephalopod diversity in the present study was generally consistent with that observed in previous years during fishery independent surveys of prawn trawl grounds. Quantifying cephalopod diversity in New South Wales commercial fisheries provides the necessary first step toward the sustainable management of these valuable resources.     

Aggregata andresi n. sp. (Apicomplexa: Aggregatidae) from the ommastrephid squid Martialia hyadesi in the SW Atlantic Ocean and some general remarks on Aggregata spp. in cephalopod hosts

A new species of coccidian, Aggregata andresi, is described from the digestive tract of the flying squid Martialia hyadesi, an ommastrephid squid that lives in cold subantarctic waters in the Southwest Atlantic. Gamogonic and sporogonic stages were observed in the digestive tract of 96.5% studied hosts. Oöcysts were ovoid to subspheroid in shape, 170–590 µm in length and 200–530 µm in width. Each oöcyst contained approximately 45,000 sporocysts. Sporocysts measured 9.5–10 µm in length and 8–8.5 µm in width. The surface of the sporocyst wall was smooth and the cyst wall thick. Each sporocyst contained three sporozoites measuring 16–20 µm in length and 2–2.5 µm width. A. andresi is the second species of Aggregata to be reported from a nerito-oceanic cephalopod host.     

Comparative-enzymological study of cholinesterases from optic ganglia of the Commander squid Berryteuthis magister individuals inhabiting different zones of the species area

In this review a comparative analysis is performed of enzymological characteristics of cholinesterase (ChE) from optic ganglia of individuals of the Commander squid Berryteuthis magister caught in 8 zones of its habitation area in the northern-western Pacific aquatorium, of ChE of the Pacific squid Todarodes pacificus as well as of the “standard” acetylcholinesterase from human erythrocytes and butyrylcholinesterase from horse blood serum. By the method of the substrate-inhibitor analysis there was shown homogeneity of ChE preparations from the B. magister individuals from different habitation zones. Kinetic parameters of the enzymatic hydrolysis of 8 ester substrates are presented as well as the data on study of identity of ChE properties in the B. magister individuals from different habitation zones. Study of the process of the ChE reversible inhibition from the Commander squid individuals under action of 57 mono- and bisonium inhibitors has revealed differences in ChE properties in squid individuals from isolates in different zones of the habitation area, which argues in favor of the existence of intraspecies groups of the Commander squid B. magister.     

Distribution of cephalopods recorded in the diet of the Patagonian toothfish (Dissostichus eleginoides) around South Georgia

The cephalopod component of the diet of Patagonian toothfish, Dissostichus eleginoides, around South Georgia was analysed from stomach contents collected between March and May 2000. Cephalopods occurred in 7% of D. eleginoides stomachs. A total of 363 cephalopod beaks were found, comprising 16 cephalopod species, of which 15 had not been previously recorded in the diet. Octopodid A (probably Pareledone turqueti) was the most important cephalopod species by number of lower beaks (36 beaks; 20.2% of the lower beaks) and Kondakovia longimana was the most important in terms of estimated mass (76% of the cephalopod component). When the cephalopod component of D. eleginoides was compared with other predators between March and May 2000, D. eleginoides fed more on octopods (25% of the lower beaks) than black-browed and grey-headed albatrosses (<1% of the lower beaks). The low frequency of the squid Martialia hyadesi in the diet of D. eleginoides around South Georgia was also noticed in the diet of albatrosses, and suggests that M. hyadesi was not present in these waters in 2000 (probably due to migratory movements or reproduction failure), despite being a candidate for commercial exploitation. The presence of the squid Mesonychoteuthis hamiltoni in the diet of D. eleginoides and being caught by a longline hook whilst presumably feeding on D. eleginoides, may indicate that juveniles of Mesonychoteuthis hamiltoni are prey of D. eleginoides adults, and when Mesonychoteuthis hamiltoni reach a large size as adults, they become the predator.     

Distribution of pelagic Ostracoda (Crustacea) inhabiting the waters around Svalbard (Arctic Ocean: 76°36–81°50N)

Although, pelagic Ostracoda are locally abundant component of the mesozooplankton in the waters around Svalbard, the group remains poorly characterised both taxonomically and ecologically. Herein, the spatial and vertical variations in abundances and species composition of the pelagic Ostracoda assemblages are examined and related to the water masses. The study is based on a series of zooplankton samples collected with a multinet plankton sampler (MPS; HydroBios, Kiel), consisting of five nets fitted with a 180-μm mesh net. Samples were collected from deep stations (i.e., with bottom depths >300 m) around Svalbard and included localities influenced by the West Spitsbergen Current and the East Spitsbergen Current and to the north of Svalbard, between years 2001 and 2006. Throughout all the samples studied Discoconchoecia elegans was the numerically dominant species. The other species found were Boroecia maxima, Boroecia borealis, Obtusoecia obtusata, and a rare novel Boroecia species. Analyses of the pelagic Ostracoda assemblages showed that their variability was predominantly influenced by four factors: water temperature, geographical position, bottom depth and season. The highest densities of D. elegans were correlated with salinities >35 PSU whereas B. maxima distribution was dependent on latitude. Highest concentrations of B. borealis were determined by longitude. Abundances of O. obtusata were positively correlated with warmer water temperatures. Thus this work suggests that halocyprids have the potential to be good indicators of environmental changes associated with shifts in climate at high latitudes in the North Atlantic.