Geographic variation in cranial morphology of narwhals (Monodon monoceros) from Greenland and the eastern Canadian Arctic

We analyzed variation in nine non-metric and eight metric variables in the skulls of 132 narwhals (Monodon monoceros) from five localities in Greenland (Inglefield Bredning, Melville Bay, Uummannaq, Disko Bay, and Scoresby Sound) and one in the eastern Canadian Arctic (Eclipse Sound). Metric variables were used to compare the combined Disko Bay and Uummannaq samples with the samples from Inglefield Bredning and Scoresby Sound using three different multivariate techniques for each sex. None of the results were significant. Seven of the non-metric variables were independent of age and sex and were used in comparing samples from the six localities. No differences were found among the four localities in West Greenland, but differences were found in two of the non-metric variables between the combined West Greenland sample and the one from Scoresby Sound. A major shortcoming of the analysis based on metric data was the small sample size from several of the areas, which resulted in low statistical power. Genetic as well as environmental factors could explain the differences detected here between narwhals living along the west and the east coasts of Greenland.     

<Emphasis Type="Italic">Boreogadus saida</Emphasis> (Lepechin) (Gadidae): a review of its metazoan parasite fauna from Greenland,eastern Canada,Alaska and the Russian Arctic

The metazoan parasite fauna of 50 specimens of Boreogadus saida (Lepechin) (Gadidae) from eastern Greenland is very similar to those of previous studies of the parasite fauna of B. saida from Greenland, eastern Canada, Alaska and the Russian Arctic. The digeneans Hemiurus levinseni, Derogenes varicus and Lecithaster gibbosus and cestode larvae were found at most stations. Single specimens of the nematode larvae Anisakis simplex were found at four stations. A comparison of the distribution of the larvae of Contracaecum sp. and Hysterothylacium sp. is difficult due to a possible confusion of the two genera. Most of the metazoan parasites of B. saida are generalist species found in several fish families. Boreogadus saida acquires most of its endoparasites by eating pelagic crustaceans, mainly copepods and amphipods. It plays an important role in the arctic ecosystem and its parasites are transferred to predatory fish, birds and mammals through the food web.     

Reproductive morphology and DNA sequences of the brown alga Platysiphon verticillatus support the new combination Platysiphon glacialis

Platysiphon verticillatus, a brown alga endemic to the Arctic, was described based on vegetative specimens collected at Inglefield Bay, West Greenland. The species is distinctive in having a lanceolate blade‐like thallus terminated by a terete portion, both covered with hair‐like assimilatory filaments. Punctaria glacialis was described from Eastern Greenland, and the species differs from other Punctaria species in lacking hairs and plurilocular zoidangia. Unilocular zoidangia were reported, but instead of zoids being released they formed cell walls in situ developing the appearance of plurilocular zoidangia. However, the fate of the zoids, as well as the walled cells was not traced, and the life history of the alga has remained unclear. By comparing DNA sequences (cox1, cox3, and rDNA ITS2) of specimens morphologically referable to Platysiphon verticillatus and Punctaria glacialis collected at Baffin Island, as well as re‐examining morphology and studying crude cultures, we concluded that they are the same taxonomic entity. Furthermore, their cox3 sequence and vegetative morphology agreed with those of the type specimen of Punctaria glacialis. Consequently, we propose Platysiphon glacialis comb. nov. The life cycle could not be completed in culture, but we hypothesize that in situ germination of the unizoids produces reduced gametophytes housed in peripheral tissue of erect sporophytic thalli.     

Movements of narwhals (<Emphasis Type="Italic">Monodon monoceros</Emphasis>) from Admiralty Inlet monitored by satellite telemetry

Twenty-one narwhals tagged in 2003 and 2004 in Admiralty Inlet showed a different summer distributional pattern than previous narwhal-tracking studies from Somerset Island, Eclipse Sound and Melville Bay. The migration of the narwhals tracked from Admiralty Inlet moved out through Lancaster Sound 15 days earlier (P < 0.0001) than the narwhals summering around Eclipse Sound, whereas the Admiralty Inlet narwhals reached the mouths of Eclipse Sound 18 days later (P < 0.0001) than the Eclipse Sound summering population. The winter range of the Admiralty Inlet narwhals overlapped with the winter range of narwhals from Melville Bay and Eclipse Sound in central southern Baffin Bay and Northern Davis Strait, but not with the winter range of narwhals from Somerset Island that wintered further north. Distribution size of range, and population size did not appear to be related. An example of considerable year to year variation between area of summer and winter distribution in the 2 years was believed to be related to the sample size and number of pods of whales tagged, rather than to differences in sex or age classes.     

Relations between the thermocline meso and microzooplankton,chlorophyll a and primary production distributions in Lancaster Sound

Summary Primary productivity in Lancaster Sound was estimated from chlorophyll and light irradiance profiles and light saturation measurments. Mesozooplankton concentrations were measured using an in situ zooplankton counter mounted on a Batfish and with the BIONESS. Microzooplankton concentrations were estimated from samples taken with the BIONESS. The horizontal and vertical distribution of the two groups of zooplankton are described and related to the distribution of chlorophyll primary production and physical features of the Sound. A westward intrusion of Baffin Bay water along the north shore of the sound which mixed with Arctic water flowing easterly resulted in a complex physical environment in the sound. The admixing of these water masses resulted in a highly variable biological structure. The thermocline was the main physical feature that affected the depth of the chlorophyll layer and the levels of primary production, with a shallow thermocline resulting in higher primary production. The admixing of Baffin Bay water with Arctic water at different areas of the sound combined with the different times of appearance of open water resulted in the populations of Calanus hyperboreus and C. glacialis showing different age structures, the youngest being in the Arctic water at the western end of the Sound. Microzooplankton populations were concentrated at various depths depending on the species. Oithona juveniles preferred the upper 10 m when the thermocline was near the surface. Most macrozooplankton were found below the thermocline and the primary production maxium. The largest concentrations of microzooplankton were found at the western end of the Sound in the Arctic water believed to be still in the biological spring.     

Parasites of the Antarctic rattail <Emphasis Type="Italic">Macrourus whitsoni</Emphasis> (Regan, 1913) (Macrouridae,Gadiformes)

A total of 386 Macrourus whitsoni from Antarctic waters were examined for ecto- and endoparasites. Sixty-five M. whitsoni collected near Halley Bay (Weddell Sea) and 321 specimens from the continental slope off King George Island (South Shetland Islands) were studied for sphyriid copepods directly after being caught. A subsample of 25 specimens from the Weddell Sea and of 9 specimens from King George Island were studied for the presence of other metazoan parasites. Twenty-two species were found, including one myxozoan, six digeneans, one monogenean, three cestodes, seven nematodes, one acanthocephalan and three crustacean species/taxa. While Auerbachia monstrosa and Capillaria sp. are reported for the first time from around the Antarctic, the other parasites have been recorded earlier in the Southern Ocean. Many parasite species found have a wide zoogeographical range and a low host-specificity. The parasite fauna of M. whitsoni revealed several similarities with its congeners M. carinatus and M. holotrachys from Antarctic and sub-Antarctic waters. This can be explained by a wide host range of many macrourid deep-sea parasites, together with an overlap in distribution patterns of their hosts. Other supporting factors are host migration and a close phylogenetic relationship between the hosts, which enable the parasites to infest all three macrourids. Eight new host and 14 new locality records are established.     

Records of the gadoid fish <Emphasis Type="Italic">Arctogadus glacialis</Emphasis> (Peters, 1874) in the European Arctic

The Arctogadus glacialis is endemic to the Arctic Ocean and its apparently disjunct circumpolar distribution range from the Siberian coast through the Chukchi Sea and the Canadian Arctic to the shelf off NE Greenland. Records of A. glacialis are scarce in the European Arctic and here we present all available and reliable records of the species in the area. Altogether, 296 specimens of A. glacialis are reported from 53 positions in the European Arctic during the period 1976–2008. The specimens were registered off Iceland and the Jan Mayen Island, northwest and northeast of Svalbard, northeast in the Barents Sea, and south and east off Franz Josef Land. The additional records show that A. glacialis display a circumpolar and more continuous distribution than described before. In the European Arctic, A. glacialis has been caught at 155–741 m depth with the highest abundance at 300–400 m. We therefore suggest that A. glacialis is more associated to the continental shelves surrounding the Arctic Ocean than previously thought. The length–weight relation of A. glacialis is similar across the European Arctic.     

Body size, sex ratio and diet composition of Arctogadus glacialis (Peters, 1874) (Pisces: Gadidae) in the Northeast Water Polynya (Greenland)

Little is known about the biology and feeding ecology of Arctogadus glacialis (Peters, 1874), an endemic gadid fish species occurring circumpolarly in both ice-free and ice-covered Arctic seas. In this study we analysed specimens sampled from bottom trawl and Agassiz trawl catches conducted at eight stations in water depths from 115 to 490 m in the Northeast Water Polynya off Greenland in August 1990. Size composition and sex ratios were assessed for 585 fish with standard lengths ranging from 7.8 to 34.5 cm. Median fish sizes at the stations ranged between 8.6 and 18.8 cm. Quantitative stomach content analyses of a subsample of 175 specimens revealed that in the Northeast Water A. glacialis fed almost exclusively on pelagic prey. Truly benthic organisms were not found in the stomachs, and sympagic species were rarely recorded. Overall, calanoid copepods were the major prey in terms of numbers. However, stomach contents varied considerably between fish size groups. In terms of prey biomass, copepods dominated the diet of small fish (<12 cm), primarily occurring at shallow stations (115–250 m), whereas amphipods and mysids were relatively more important for larger fish (>16 cm), which dominated the catches at deep stations (360–480 m). The broad variety of diet composition indicated an opportunistic pelagic feeding pattern. Received: 6 November 1997 / Accepted: 11 May 1998     

Assemblages of sea stars (Echinodermata: Asteroidea) and brittle stars (Echinodermata: Ophiuroidea) in the Weddell Sea (Antarctica) and off Northeast Greenland (Arctic): a comparison of diversity and abundance

Composition and distribution of asteroid and ophiuroid assemblages were investigated by means of Agassiz trawl catches at 34 stations in 220- to 1,200-m depth in the Weddell Sea and at 17 stations in 90- and 830-m depth off Northeast Greenland. A total of 86 species (48 sea stars, 38 brittle stars) were identified in the Weddell Sea whereas off Northeast Greenland a total of 26 species (16 sea stars, 10 brittle stars) were recorded. In both study areas, brittle stars were numerically more important than sea stars, and abundances generally decreased with water depths. Multivariate analyses revealed a conspicuous depth zonation of sea and brittle stars off Greenland. Very high abundances of Ophiocten sericeum and Ophiura robusta characterized the assemblages on shallow shelf banks whereas in greater depths Ophiopleura borealis, Ophioscolex glacialis and Ophiacantha bidentata became dominant, albeit at significantly lower densities. Mass occurrences of brittle stars, such as those recorded on Greenlandic shelf banks, have not been discovered in the Weddell Sea, where distinct assemblages were discriminated in deep shelf trenches as well as on the eastern and southern shelf. Ophioplocus incipiens, Ophiurolepis martensi and Ophiurolepis brevirima were the most prominent species on the eastern shelf. Ophiacantha antarctica, Ophiurolepis gelida and Ophionotus victoriae on the southern shelf, and Ophiosparte gigas as well as the asteriod Hymenaster sp., in the shelf trenches. Overall, the Weddell Sea housed conspicuously more asterozoan species than the waters off Greenland. Higher species diversity was also evident at both a regional and local scale, especially for the eastern Weddell Sea shelf. However, because many species from the Weddell Sea are closely related, the Weddell Sea assemblages were not significantly different from the Greenland ones in terms of taxonomic diversity and distinctness. Received: 29 April 1996/Accepted: 10 June 1996     

<Emphasis Type="Italic">Careproctus kidoi</Emphasis>, a new Arctic species of snailfish (Teleostei: Liparidae) from Baffin Bay

Careproctus kidoi sp. nov. is described from the Baffin Bay between Greenland and Canada, in the northern most part of the western North Atlantic. During a series of bottom trawl surveys conducted in 1988–2004, 22 specimens of an undescribed species of Careproctus were caught at depths between 952 and 1,487 m. It differs from Arctic and North Atlantic congeners in the combination of the characters: pectoral fin rays 21–26, dorsal fin rays 54–60, anal fin rays 50–54, vertebrae 61–64; sucking disc oval, 4.2–6.6% SL; teeth simple; pyloric coeca 3–12; head pore formula (2-6-7-1); color light to dark brown, stomach dusky to dark brown, peritoneum black. It is generally found in deeper waters than the sympatric C. reinhardti.     

Ovary development in Greenland halibut Reinhardtius hippoglossoides in west Greenland waters

Maturity in adult female Greenland halibut Reinhardtius hippoglossoides was studied in three areas in west Greenland waters: the inshore area in Disko Bay and two offshore areas, Baffin Bay and Davis Strait. The aim was to monitor maturity changes in the inshore fjords of Disko Bay over an extended period from winter to autumn and compare these findings with specimens from Baffin Bay and the presumed spawning area in Davis Strait. A significant difference in maturity level was observed in and between the three areas. In Disko Bay maturity indices increased significantly in August and September both with respect to the gonado‐somatic index ( I _G) and the size in the leading oocyte cohort. In the period February to May no significant changes were observed. Mature ovaries were only observed among fish >80 cm total length and only among a fraction of these large fish. Offshore areas of Baffin Bay, even though poorly sampled, showed similar signs in the maturity indices as in Disko Bay. Relative to Disko Bay and Baffin Bay, female fish in Davis Strait had more progressed maturity indices. Furthermore, almost all fish in Davis Strait showed signs of progressed maturity contrary to Disko and Baffin Bay. A large proportion of the Greenland halibut in Disko and Baffin Bay apparently did not begin the maturation cycle until very late in their life history or were repeat spawners with a multi‐year maturation cycle. These observations could thus support the hypothesis that Greenland halibut have a prolonged adolescent phase. Atresia was highest in the early phases of maturation in Greenland halibut but relatively high levels of atresia were also observed in fish in more advanced maturity phase. The first was ascribed to fecundity regulation while the latter could be linked to the fish's fitness condition but it was not possible to show this with the available condition index.     

Anisakis simplex (s.s.) larvae in wild Alaska salmon: no indication of post-mortem migration from viscera into flesh

The prevalence, mean intensity and distribution of Anisakis nematode third-stage larvae (L3) in the muscle and viscera of wild-caught chum salmon Oncorhynchus keta, pink salmon O. gorbuscha and sockeye salmon O. nerka were compared immediately after catch. Salmon were collected during the fishing season in July 2007 in Bristol Bay and Prince William Sound close to Cordova, Alaska (USA). All fish were infected, and more than 90% of the nematode larvae were found in the edible muscle meat. The isolated anisakid L3 were genetically identified as A. simplex (s.s.). The distribution of nematodes in the muscle meat of fresh-caught salmon was examined in 49 O. keta, 50 O. nerka and 12 O. gorbuscha from Cordova. Most of the larvae were detected in the muscle parts around the body cavity, but nematodes were also found in the tail meat and epaxial muscle (loins). The mean intensity of Anisakis larvae in the edible part was 21 individuals for O. gorbuscha, 62 individuals for O. keta and 63 individuals for O. nerka. No difference in the intensity of Anisakis larvae in the hypaxial muscle was found between fresh-caught and immediately gutted salmon and individuals stored ungutted for 24 h either on ice or in refrigerated sea water.     

Recent Arctic marine diatom assemblages from bottom sediments in Baffin Bay and Davis Strait

This study investigates the present geographical boundaries and environmental limits of the diatom flora in the Baffin Bay and Davis Strait area. Seventy-four sea floor surface samples were examined. The raw data were analyzed with the CABFAC factor analysis program. Five factor assemblages, explaining 87% of the observed variance, emerged from this test. The statistically most important assemblage is the “Baffin Current assemblage”, composed ofThalassiosira gravida spores. The second assemblage is the “summer pack ice assemblage”, consisting ofActinocyclus curvatulus, with a lesser contribution ofThalassiosira trifulta. A third assemblage, dominated byThalassiosira hyalina, is located along the southwest coast of Greenland, indicating low ice concentration. The fourth assemblage consists ofPorosira sp. spores and indicates fast ice conditions. The fifth assemblage is dominated byThalassionema nitzschioides andPorosira glacialis (vegetative cells), and indicates the coastal environment. Diatoms found in the sediment belong to discrete assemblages which reflect differences in water masses, such as salinity and ice conditions. These findings should assist in the interpretation of paleoceanographic conditions in the region when diatom assemblages are studied in piston core sediments.     

Autumn migration and wintering of northern fulmars (<Emphasis Type="Italic">Fulmarus glacialis</Emphasis>) from the Canadian high Arctic

Five northern fulmars (Fulmarus glacialis) were tracked by satellite transmitters from their breeding colony in the Canadian high Arctic (Cape Vera, Devon Island, NT) to their wintering grounds in the northwest Atlantic Ocean. In both 2004 and 2005, fulmars left northern Baffin Bay in mid- to late September, and migrated south to Davis Strait in less than 1 week, after which movements were erratic. In October and November, the birds were widely distributed, but by December through March, they tended to remain in the Labrador Sea between 50 and 55°N. Average flight speed was 35 km/h with a maximum of 64 km/h, and over their entire transmission periods, the five traveled on average 84 km/day. Our work suggests that the North Atlantic northern fulmar population may be panmictic in winter, with the Labrador Sea as a key wintering site for fulmars from high Arctic Canada.     

Nosema takapauensis n.sp., a microsporidan parasite of larvae of Costelytra zealandica (Coleoptera: Scarabaeidae) in New Zealand

Morphological and biological features of a microsporidan protozoan parasite of larvae of Costelytra zealandica collected at Takapau, southern Hawkes Bay, are described and evaluated taxonomically. The parasite multiplies in the fat body of all larval instars, causing massive tissue disintegration in advanced infection resulting in the retardation of development and ultimately death before pupation. The microsporidan forms one spore per sporont, and therefore belongs to genus Nosema’, it is considered to be specifically distinct from its nearest congener, N. melolonthae.     

Further evidence of spawning of bluefin tuna (Thunnus thynnus L., 1758) and the tuna species (Auxis rochei Ris., 1810, Euthynnus alletteratus Raf., 1810) in the eastern Mediterranean Sea: preliminary results of TUNALEV larval survey in 2004

A tuna larval survey (TUNALEV) in the Northern Levantine Basin (Cilician Basin) was conducted onboard a trawler from 5 to 18 June 2004. To determine the spatial distribution and abundance of tuna larvae, Bongo 60 and Bongo 90 nets were used. Ichtyoplankton samples from 104 stations were taken. In total, 121 bluefin tuna (Thunnus thynnus), 94 bullet tuna (Auxis rochei) and 22 Atlantic black skipjack (Euthynnus alletteratus) larvae were collected. In comparison with the other tuna larvae, the concentration of bluefin tuna larvae was highest in the Bay of Mersin. The collected larvae in this area were composed mainly of 5–9 mm size specimens.     

Morphological studies of Ancyracanthopsis winegardi Wong & Anderson, 1990 (Nematoda: Acuarioidea) and larval stages of acuariid nematodes parasitic in Larus dominicanus Lichtenstein (Aves: Laridae) from Argentina

Ancyracanthopsis winegardi Wong & Anderson, 1990 (Nematoda: Acuarioidea) is described from Larus dominicanus Lichtenstein (Aves: Laridae) on the Southwest Atlantic coast (38° 42S, 59° 47W). The main character used to distinguish species of Ancyracanthopsis is the morphology of the ptilina. Thus, although the specimens described here have some differences in the morphology and size of the spicules and in the female genitalia, they were referred to A. winegardi because they have a very similar ptilina. This is the first record of a member of Ancyracanthopsis from larid birds and for A. winegardi in the Southwest Atlantic coast. We have also studied acuariid larvae found inhabiting the gizzard alongside adult specimens of A. winegardi. Among those larvae, two morphological groups were clearly distinguished. The first group was characterised by the absence of ptilina and the presence of spicular primordia and rectal cells (third-stage larvae). The second group could be distinguished by the presence of ptilina and partly-developed genitalia (fourth-stage larvae). In order to identify the larvae, a Principal Component Analysis was applied to morphometric data taken from the third-stage larvae. These results and the morphology of the partly-developed ptilina of the fourth-stage larvae indicated that the larval stages found in L. dominicanus appear to belong to Sciadiocara haematopodi, Cremonte, Navone & Etchegoin, 1999.     

Population genetics ofAnisakis simplex (Nematoda: Ascaridoidea) in Atlantic salmon (Salmo salar) and their use as biological indicators of host stocks

Synopsis The extent to which data concerning the population genetics of a parasite — namely larvalAnisakis simplex, may be used as an auxilliary source of information on various aspects of the marine migrations of Atlantic salmon (Salmo salar) is examined.Frequencies of the various acid phosphatase alleles could not be used in distinguishing between or estimating the proportions of North American and European salmon occurring off west Greenland. The genetic structure of larvae from salmon taken in Scotland was different from that taken in Ireland and England confirming an earlier conclusion that the feeding habits of the fish from Scotland were significantly different. In the western Atlantic, salmon from northern Newfoundland and also salmon from the Bay of Fundy had apparently ingested different populations (or different proportions of the same nematode population) than salmon from Miramachi and Chaleur Bay areas. Samples from northern Newfoundland and Labrador were also genetically different. These findings are discussed in relation to the available literature concerning salmon migrations, explanations are put forward and areas of future research suggested.     

Distribution,prevalence and mean numbers of larvalAnisakis simplex (Nematoda: Ascaridoidea) in Atlantic salmon,Salmo salar L. and their use as biological indicators of host stocks

Synopsis An estimate of the arithmetic mean number of larvalAnisakis simplex per salmon,Salmo salar, in the north Atlantic was obtained from data collected off west Greenland where salmon from both sides of the Atlantic intermingle. An average of 5.34 larvae was found in the body cavity or associated viscera of 771 age 1 salmon representing some 60.8% of the total number of larvae present. LarvalA. simplex were found at all sampling stations throughout the north Atlantic. In most samples prevalence varied only slightly from area to area.The mean numbers of larvae in the body cavity and on associated organs of salmon in samples from North America were significantly different between samples. Comparisons of the mean numbers of larvae with several known variables in the data were, therefore, considered: host's sex, host's sea-age, geographic locality, year and season of capture.There was evidence that the mean number of larvae per host was greater in salmon from Europe than in those from North America, but the data could not be used to providereliable estimates of the mean numbers of larvae from each area because of heterogeneity within areas. Thus the data from west Greenland and from continental home waters could net be used in calculations to determine the percentage composition of North American and European salmon in the Greenland fishery although they supported earlier findings of mixing of salmon stocks off west Greenland.The use of parasitological data in the identification of different Atlantic salmon stocks is discussed.     

A new zoarcid, Lycodes mcallisteri, from eastern Arctic Canada (Teleostei: Perciformes)

A new zoarcid fish, Lycodes mcallisteri, is described on the basis of nine specimens (230–375 mm SL) from eastern Arctic Canada, Nunavut (Hudson Strait, 298 m; Cumberland Sound and Baffin Bay, 579 m). It resembles about 15 other Lycodes spp. in having a long tail and a "ventromediolateral" type of lateral line. It is distinguished from Arctic members of this group (Lycodes marisalbi, L. palearis, and L. sagittarius) by the high number of pectoral fin rays (22–23), short pelvic fins, low submental crests, and coloration (6–10 light patches dorsally). It resembles two Pacific species (L. macrochir and L. soldatovi) by the high number of pectoral fin rays, but differs by coloration, meristics, and shape of the pectoral fin. Received: April 13, 2000 / Revised: September 7, 2000 / Accepted: January 11, 2001