Ommastrephes Research Articles

COMPARISON ON TRACE ELEMENTS IN SQUID STATOLITHS OF DIFFERENT SPECIES' ORIGIN: AS AVAILABLE KEY FOR TAXONOMIC AND PHYLOGENETIC STUDY

Trace elements in squid statoliths were analyzed by PIXE for the following fourteen species in five families of different habitat origin: Ommastrephidae, Ommastrephes bartrami, Dosidicus gigas, Sthenoteuthis oualaniensis; Gonatidae, Gonatopsis makko, G. borealis, Berryteuthis magister; Loliginidae, Loligo bleekeri, L. duvaucelii, L. chinensis, L. edulis and Sepioteuthis lessoniana; Sepiidae, Sepia aculeata and Sepiella inermis; Sepiolidae, Rossia pacifica, Manganese, iron, copper, zinc and strontium were detected from statoliths of all species examined. Among these trace elements, Sr is the highest in concentration. Variation of statoliths Sr concentration reflects taxonomic position and the habitat of specimens. In Ommastrephids and Gonatids, that have oceanic habitat, statoliths Sr concentration is relatively high whereas that of Loliginids and Sepiids, that have coastal habitat, is comparatively low. This fact supports our previous report on this subject. R. pacifica exceptionally shows high statoliths Sr concentration although this species inhabits in coastal water.

集魚灯下で釣獲されたアカイカの網膜順応状態

To investigate the mechanism of attracting large-sized neon flying squid (>30cm mantle length), Ommastrephes bartrami, to fishing lights, experimental hand and machine jigging with fishing lights were carried out in the North Pacific Ocean. The eyes of captured squid were examined histologically for retinal adaptation. Squid were caught at different depths (20, 50, 100, 150, 200m) using onboard fishing lights at night and in the daytime with underwater fishing lights placed 180m deep. Their retinae were all dark-adapted when captured during the daytime and at night. Since squid were caught at nighttime at greater than 100m depths using jigs with 300kW fishing lights, it is supposed that the powerful fishing lights have deepened the distribution of squid whereas driftnets captured squid at depths of 7-10m when set at night.

Foods of Northern Fulmars Associated with High-Seas Drift Nets in the Transitional Region of the North Pacific

We examined digestive tract contents and nitrogen stable isotope ratios in breast muscles of northern fulmars (Fulmarus glacialis) salvaged from squid and large-mesh drift nets in the transitional North Pacific. Lantern fishes (Myctophidae) were the principal prey item found in the digestive tracts. Pieces of unidentified fishes (probably Pacific pomfret Brama japonica) and shredded squid tissue (probably neon flying squid Ommastrephes bartrami) indicate scavenging at fishing operations. Although soft-bodied prey such as Velella were not found in the digestive tracts, 815N values suggest that fulmars may feed heavily on such low trophiclevel animals. Northern fulmars (Fulmarus glacialis) have been reported to feed on varying amounts of squids, fishes, zooplankton, carrion, and offal, probably varying with what is most available in various locations and seasons (Hunt and others 1981; Furness and Todd 1984; Hills and Fiscus 1988; Hatch 1993). Most of these studies have emphasized the importance of cephalopods, although several suggest that small fishes may be most important to the overall diet. We have found only two references to lantern fishes in the diets of northern fulmars from other areas (Schneider and others 1986; Hatch 1993). In the Gulf of Alaska, Sanger (1987) assigned northern fulmars to the highest trophic level among the 19 marine bird species studied and suggested that these birds were third-order carnivores. No studies of feeding by northern fulmars have been conducted on their wintering grounds in the central North Pacific, however. As part of our efforts to assess the impact of North Pacific drift net fisheries on marine birds (Gould and Hobbs 1993; Johnson and others 1993), we examined the digestive tracts and stable nitrogen isotopes in the breast muscles of a small sample of non-breeding northern fulmars salvaged from drift nets set in the transitional region of the central North Pacific. STUDY AREA AND METHODS Specimens were salvaged from large-mesh and squid drift nets set by ships from Japan, Taiwan, and the Republic of Korea (Ito and others 1993). In 1991, 29 northern fulmar specimens with complete digestive tracts were obtained in the area bounded by 40° to 44°N and 171°E to 172°W, and between 9 September and 18 November; however, all but 2 of the specimens were taken in October. The sample included 17 females and 12 males, and ages varied from newly fledged juveniles to breeding-age adults, as judged by bursa sizes (length x width) that ranged from 0 to 582 mm2 (x = 294.3, SD = 155.7). Only 2 of the specimens lacked bursas, so most of our specimens had not yet achieved breeding status (Siegel-Causey 1990). In addition, 9 birds were salvaged in 1990 (37° to 46°N, 153°E to 152°W; June to November) and 3 birds with stomachs but without gizzards were examined from 1991. Data from these 12 specimens are included as anecdotal information in this report.

Lipase from neon flying squid hepatopancreas: purification and properties

Lipase from hepatopancreas of the neon flying squid ( Ommastrephes bartramii) has been partially purified. The molecular weight determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was 33 000. Optimum pH was around 7.0 and the enzyme was relatively stable between pH 6.0 and 9.0 for 6 h at 25 °C. Optimum temperature of the enzyme reaction was around 25 °C. The enzyme was tolerably stable up to 37 °C. Several triglyceride (TG) molecular species were used as substrates for investigating the positional and fatty acid specificities of the enzyme. With respect to the hydrolysate of TG, the enzyme examined was not an sn-1,3 or an sn-2 positionally specific lipase. The enzyme appeared to have specific activity on monounsaturated and saturated chain TGs, most likely oleic and/ or palmitic acid. In this study, colipase was also separated from the enzyme.

Species associations of epipelagic nekton of the North Pacific Ocean, 1978–1993

ABSTRACTStrong latitudinal gradients in species composition were revealed by two‐way indicator species analysis (TWINSPAN) and detrended correspondence analysis (DCA) of 41 species of epipelagic fishes and squids in 513 gillnet collections by research vessels of Hokkaido University over a huge area of the northern North Pacific during the summers of 1978–1993. Salmonids inhabited northern subarctic water and skipjack tuna (Euthynnus pelamis) and flying squid (Ommastrephes bartrami) inhabited the region of the Subarctic Boundary, but distinct boundaries between species groups and sample groups were lacking, largely because abundant species, such as Pacific saury (Cololabis saira) and Pacific pomfret (Brama japonica), migrated across most of this region during the summer. Longitudinal differences were not pronounced, but some species, including Japanese sardine (Sardinops melanostictus) and Japanese anchovy (Engraulis japonicus), were only found in the western Pacific. Pacific saury was more common in the western Pacific, whereas sockeye salmon (Oncorhynchus nerka) was concentrated in the eastern Pacific. Interannual fluctuations in the latitude of species groups were most closely correlated with changes in sea surface temperatures. In the western Pacific, 1982, 1983, 1985, 1987‐88, and 1992‐93 were cool years when subarctic and transitional assemblages were found farther to the south than other years. Temperature and salinity at various depths were highly correlated with each other and with first‐axis DCA ordinations scores. Long‐term trends in community structure were not apparent during the 1.6 decades.

PIXE ANALYSIS OF TRACE ELEMENTS IN SQUID STATOLITHS: COMPARISON BETWEEN OMMASTREPHIDAE AND LOLIGINIDAE

Trace elements in the squid statoliths were analyzed by PIXE for following seven species distributing at offshore and inshore waters: Family Ommastrephidae, Ommastrephes bartrami, Todarodes pacificus; family Loliginidae, Loligo bleekeri, L. duvaucelii, L. chinensis, L. edulis and Sepioteuthis lessoniana. Statoliths of all seven species contained manganese, iron, capper, zinc and relatively high amount of strontium. Statoliths Sr concentration, an possible index for thermal history of the animal’s habitat, were the highest in O. bartrami that spends their entire life time at pelagic water, and secondly highest in T. pacificus living at the pelagic as well as the coastal waters. On the other hand, statoliths Sr concentration was relatively low in the five species of Loliginidae living at coastal waters, with following order: L. edulis >S. lessoniana >L. duvaucelii >L. bleekeri >L. chinensis. These observations may indicate that quantity of the statoliths trace elements are species specific in squids, thus would be a possible “key” to reconsidering about taxonomy and distribution in squid.

Effect of soaking time on catch-per-unit-effort of major species taken in the Japanese squid driftnet fishery in 1990

We made a preliminary analysis of the effect of soaking time on the catch of the Japanese squid driftnet fishery in the central North Pacific in 1990. In a typical fishing operation, eight or nine net sections (each 4–7 km long) were used. Net retrievals began from the last section deployed. The soaking time for each section ranged from approximately 5 to 19 h, based on 993 fishing operations by 75 vessels monitored by scientific observers from Canada, Japan and the USA. The relationship between soaking time (indexed by section retrieval order number) and average catch in number per net panel or tan (catch-per-unit-effort, CPUE) revealed three patterns depending on the species entangled. These patterns included: (1) positive relationship between CPUE and soaking time throughout the sections (blue shark and salmon shark); (2) positive relationship within the first three to six sections, which were probably retrieved during the night and dawn, but constant or slightly decreased CPUE in later sections retrieved in day time (neon flying squid, Pacific pomfret, seabirds); (3) negative relationship (pelagic armorhead). These different patterns were considered to represent primarily the behavior of species, diel vertical migration or diel feeding activity, and secondly drop out from the nets and predation.

Allozyme differentiation of sixteen species of ommastrephid squid (Mollusca, Cephalopoda)

Allozyme differentiation was investigated at 23 putative enzyme coding loci in 16 ommastrephid squids to identify species and to assess genetic relationships. The species examined were Illex illecebrosus, I. coindetii, I. argentinus, Todaropsis eblanae, Todarodes sagittatus, T. angolensis, T. filippovae, T. pacificus pacificus, Nototodarus sloanii, N. gouldi, Martialia hyadesi, Ommastrephes bartramii, Sthenoteuthis pteropus, S. oualaniensis, Eucleoteuthis luminosa, and Dosidicus gigas. A dendrogram based on Nei's genetic distance between the species closely approximates to the latest systematics based on morphological characters, but the positions of M. hyadesi and T. eblanae were considerably distant from all other species. The results demonstrate the benefits of further biochemical analysis to an understanding of the systematics of the ommastrephid squids.

The Ecological Aspects of Neon Flying Squid Ommastrephes bartrami in Summer off the West Coast of the US.

The Ecological Aspects of Neon Flying Squid Ommastrephes bartrami in Summer off the West Coast of the US.

Potential use of helminth parasites in stock identification of flying squid, Ommastrephes bartrami, in North Pacific waters

A survey of helminth parasites in 68 flying squid (Ommastrephes bartrami) from off the west coast of North America (between latitudes 41°03′ and 48°23′ N and longitudes 129°49′ and 133°08′ W) revealed the presence of numerous juvenile nematodes and cestodes. Larval Hysterothylacium sp. and metacestodes of Phyllobothrium sp. were common (prevalence: 100 and 94.1%, respectively; mean intensity: 54.6 ± 28.1 and 6.4 ± 4.5, respectively). In addition, nine flying squid had a total of 11 Anisakis simplex larvae, and one metacestode of Tentacularia sp. (probably T. coryphaenae) was found in the sample bag that held one flying squid. The only adult helminths recovered were seven specimens of Rhadinorhynchus sp. (Acanthocephala) from three squid. The parasite fauna of these squid was sufficiently different from that previously reported for O. bartrami from the northwestern Pacific Ocean to suggest that parasites may prove useful as a tool to determine if intermixing of squid stocks from their feeding grounds in the eastern and western North Pacific Ocean occurs on the spawning grounds.

A Study of the Antioxidative Substance(s) in Squid Mantle Muscle.

The lipid peroxidation suppressing ability of whole lipid extracted from commercially purchased squid mantle muscle of three common squids, i.e., Japanese common squid (Todarodes pacificus), flying squid (Ommastrephes bartrami) and short-finned squid (Illex argentinus), was evaluated by the progress of peroxide value (PV) and carbonyl value (CV) of purified sardine oil with or without addition of whole lipid fraction at 10% level. Every whole lipid extracted from the three species of squid markedly suppressed the peroxidation of purified sardine oil. The whole lipid of I. argentinus showed the strongest suppressive activity of the three. Neither differences in compositions of lipid and fatty acids nor content and composition of tocopherols in the mantle muscle could sufficiently account for their antioxidative ability. The addition of purified phospholipid fraction, fractionated from the whole lipid of I. argentinus, to purified sardine oil at the concentration of 5% (w/w) markedly suppressed the peroxidation of sardine oil.

Oceanic resources of squids∗

In this paper, the biological characteristics of commercially important oceanic squids, Japanese common squid Todarodes pacificus and flying squid Ommastrephes bartrami in the North Pacific, including population structure, reproduction, growth, migration and feeding are discussed. History and present state of Japanese squid jigging fishery and squid drift gillnet fishery are then presented. Finally, methods of stock assessment, estimated stock parameters, annual variation in stock size and resource management for these two oceanic squids are dealt with.

Time Courses of Total Volatile Basic Nitrogen (TVB-N) in Seafoods Inoculated Singly or as Mixtures with Spoilage Yeasts or Bacteria

Previously, we reported on the amount of T-VBN produced by yeasts or bacteria. Candida lipolytica produced the largest amount of T-VBN among the 5 yeast species tested, while Staphylococcus epidermidis produced the smallest amount, and Pseudomonas fluorescens produced the largest amount among the 4 bacterial species tested. In this paper, the microbiological and chemical changes of these 3 species were compared. C. lipolytica, S. epidermidis and P. fluorescens were inoculated singly or as mixtures into 3 different kinds of sterile seafood homogenate (common mackerel, black tiger shrimp and neon flying squid), and incubated at either 5, 15 or 25°C. The time courses of viable counts, pH values, and TVB-N values determined according to the microdiffusion method of Conway were observed for up to 7 days.(1) Viable counts: The growth curves of C. lipolytica at 15 and 25°C showed gradual slopes, and reached the stationary phase on day 7. The growth curves of P. fluorescens and a mixture containing C. lipolytica, S. epidermidis and P. fluorescens at 15 and 25°C reached the stationary phases on day 2. The growth curves of S. epidermidis at 5 and 15°C were lower than those of C. lipolytica, P. fluorescens and a mixture of all three.(2) pH: The pH values in the seafood homogenate inoculated with C. lipolytica, P. fluorescens and a mixture of all three increased with temperature and duration of incubation.(3) TVB-N: Whereas the viable counts at 25°C of C. lipolytica were less than those of P. fluorescens, S. epidermidis and the mixture, the production of TVB-N by C. lipolytica was at almost the same levels as those of P. fluorescens and the mixture, and considerably more than that of S. epidermidis. The results of the previous and present experiments have thus confirmed that the yeasts produced the same spoilage phenomenon as the bacteria.

Food of the squidOmmastrephes bartramii(Lesueur, 1821) from the South-West Atlantic Ocean

The diet of Ommastrephes bartramii (Lesueur, 1821) was determined by analysing the stomach contents of 73 squid caught in the South-West Atlantic Ocean. There were three main prey groups, Cephalopoda (in 82% of the squid stomachs), Osteichthyes (34%) and Crustacea (18%). Cannibalism was common. Squid of the families Histioteuthidae and Enoploteuthidae and other teuthoids were less frequent in the diet. The fish prey was predominantly Myctophidae, of various species. The bulk of the prey was mesopelagic species that migrate into the epipelagic layers at night.

On the flying behavior of neon flying squid Ommastrephes bartrami observed in the central and northwestern north Pacific.

The flying behavior of neon flying squid was observed at 8 different locations in the subtropical region between long. 160°E and 172°W along lat. 37°N (surface temperature: 17-24°C), on board the R/V Omi-Maru in the period from July to August, 1984. Roughly 10-300 squids (estimated mantle length: 14-18cm) flew a distance of 10-20m at a height of 1-2 m above the sea surface in the same direction both by day and by night. The form of squid in flight closely resembled that of purpleback flying squid. Judging from these results, it is beleived that the smaller individuals under about 18cm in mantle length of neon flying squid live mainly near the surface of the sea, by day and night, and that they have a gliding-type flying behavior like flying fish, mainly to escape from their enemies.

Some biological aspects of neon flying squid Ommastrephes bartrami caught by Japanese squid gillnetters in the North Pacific.

In order to elucidate the stock structure and growth of neon flying squid, seasonal variations in dorsal mantle length, sex ratio, gonad weight and degree of sexual maturity of this species are presented here on the basis of the results of biological measurements of the samples taken by squid gillnetters during June and December in 1983-1985. The majority of the sampled squid were immature and not copulated females, while the proportion of males in number was only 2.4% in the 3-year average, and about half of the males were semi-mature (11%) or mature (36%). The principal modal mantle length in females shifted from 37cm level in June to 45cm level in September, then backed again to a smaller modal size within the range of 35-41cm in October-November. The ovary weights showed a general tendency to gradually increase between June and August, but this was followed by an abrupt decrease in September. Judging from these results, it is presumed that Japanese squid squid gillnetters mainly catch “extra-large sized” group of neon flying squid in June-September and “large sized” one in October-December, selectively out of four different size groups in the northern North Pacific.

Studies on biological activities of melanin from marine animals. V. Anti-inflammatory activity of low-molecular-weight melanoprotein from squid (Fr. SM II).

Low-molecular-weight melanoprotein obtained from Ommastrephes bartrami LESUEL (Fr. SM II) was subjected to an anti-inflammatory screening procedure and was shown to have a potent inhibitory activity against carrageenin-induced rat paw edema. Fr. SM II was then studied with various acute inflammatory models and appeared to suppress the enhanced capillary permeability of mouse ear induced by xylene and the acceleration of vascular permeability induced by compound 48/80. Using the carboxymethylcellulose pouch method, both leucocyte emigration and protein exudation into the pouch fluid were potently inhibited by Fr. SM II. Fr. SM II was also effective in subacute inflammation induced by the felt pellet and the croton oil granuloma pouch methods. Thus, in addition to its anti-ulcerogenic activity, Fr. SM II also has anti-inflammatory activity.

Studies on biological activities of melanin from marine animals. I. Purification of melanin from Ommastrephes bartrami Lesuel and its inhibitory activity on gastric juice secretion in rats.

Crude squid melanin obtained from ink bags of Ommastrephes bartrami LESUEL was found to exhibit a strong inhibitory effect on gastric secretion in rats. The crude melanin was separated into high molecular fraction SM I (mol. wt.>160000) and low molecular fraction SM II (average mol. wt. ca. 39000) by gel filtration on a Sephadex G-100 column, and Fr. SM II showed a stronger biological activity. Fr. SM II contained a melanoprotein composed of melanin pigment 90%, protein 5.8% and carbohydrate 0.8%, and significantly decreased gastric secretion at the dosage of 1 mg/kg, i.p. or i.v. Fr. SM II also prevented ulcer formation in pylorus-ligated rats and aspirin-induced ulcer.

High copper concentrations in squid livers in association with elevated levels of silver, cadmium, and zinc

Livers from 43 Loligo opalescens, 14 Ommastrephes bartrami, and 7 Symplectoteuthis oualaniensis were analyzed for their silver, cadmium, copper, zinc and iron contents. Copper concentrations of up to 15,000 μg/g dry weight were found in L. opalescens in conjunction with significant correlations between this element and Ag, Cd and Zn. The latter elements are known to affect Cu metabolism in terrestrial organisms; however, whether the correlations occurring in marine organisms represent casual, or cause and effect, relationships is as yet unknown.