Taxonomic Reevaluation of the Spiny Dogfish (Squalus acanthias L.) in the Northeastern Pacific Ocean

1976 ◽  
Vol 33 (11) ◽  
pp. 2500-2506 ◽  
Author(s):  
Barry C. Jones ◽  
Glen H. Geen
Keyword(s):  
Pacific Ocean ◽  
North America ◽  
Squalus Acanthias ◽  
Spiny Dogfish ◽  
Morphometric Data ◽  
Biochemical Characteristics ◽  
Cosmopolitan Species ◽  
Northeastern Pacific ◽  
East And West ◽  
The Individual

Morphometric ratios, vertebral counts, and electrophoretic analyses of spiny dogfish from east and west coasts of North America indicate that those in the northeastern Pacific Ocean comprise one of several discontinuous stocks of the cosmopolitan species Squalus acanthias L. Though the individual stocks exhibit statistically significant differences in meristic and biochemical characteristics, available data do not support subspecific status for any of the groups around the Americas. The inadequacy of certain morphometric data to distinguish between Squalus species is also discussed.

Biology and Management of Dogfish Sharks

2009 ◽  
Keyword(s):  
Pacific Ocean ◽  
Puget Sound ◽  
Squalus Acanthias ◽  
Spiny Dogfish ◽  
Commercial Fishery ◽  
Stock Assessments ◽  
Northeastern Pacific ◽  
Georgia Basin ◽  
Hexanchus Griseus

Abstract.—Predatory interactions of bluntnose sixgill shark <em>Hexanchus griseus </em>and spiny dogfish <em>Squalus acanthias </em>were evaluated as part of a longline tagging study for sixgill sharks in a northeastern Pacific Ocean estuary, the Puget Sound/Georgia Basin (PSGB). This study shows that sixgill sharks will prey upon dogfish. Dogfish were caught in one of three ways: as whole individuals, with parts of their bodies consumed, or as whole individuals with sixgill sharks retained on the hook as well. Bait experiments showed that for one of two sampling periods, hooks baited with dogfish were preferred by sixgill sharks over hooks baited with herring. Analysis of sequential hook data revealed that sixgill sharks were caught on the longline at areas where dogfish were caught in low to intermediate densities, suggesting little preference for the movement of a hooked dogfish. Given that the dogfish population in the PSGB supports a commercial fishery, the importance of the dogfish as sixgill-shark prey may need to be considered in future fishery stock assessments and allowable catch limits may need to be lowered to leave a sufficient source of nutrients for the sixgill-shark population.

scholarly journals Life-history traits of the spiny dogfish Squalus acanthias in the Adriatic Sea

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Giada Bargione ◽  
Fortunata Donato ◽  
Mario La Mesa ◽  
Carlotta Mazzoldi ◽  
Emilio Riginella ◽  
...  
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Adriatic Sea ◽  
Growth Parameters ◽  
Sampling Period ◽  
Squalus Acanthias ◽  
Spiny Dogfish ◽  
The North ◽  
Size At Sexual Maturity ◽  
The Individual

Abstract Pivotal life history traits concerning age structure and reproduction of the spiny dogfish (Squalus acanthias, Linnaeus 1758) were investigated in the Adriatic Sea from mid February 2012 to mid July 2013 and in 2016. The whole sample consisted of 176 females and 150 males, ranging between 217–1025 mm and 219–875 mm, respectively. The individual age, which was estimated using a cross-sectioning technique of the second dorsal-fin spine, ranged from 0 to 13+ years for females and from 0 to 9+ years for males. Based on the length-at-age estimates, the Gompertz growth parameters were L∞ = 1130 mm, k = 0.18 and L∞ = 920 mm, k = 0.24 for females and males, respectively. The size at sexual maturity (L50) was 659 mm for females and 575 mm for males, corresponding to 7.5 and 5.5 years of age (A50), respectively. Mean biennial fecundity was approximately 11 embryos/female and 12 ripe oocytes/female. Mature males occurred during much of the sampling period, while mature females with nearly full-term embryos were exclusively recorded in May 2013 and July 2016. Monitoring of catches conducted in a sample port of the north Adriatic (Chioggia) over the past 20 years has shown fluctuating trends in landings, with peaks during the summer reproductive season.

XXXIII.—The Blood Vascular System of the Spiny Dogfish, Squalus acanthias Linné, and Squalus sucklii Gill

1928 ◽  
Vol 55 (3) ◽  
pp. 823-890 ◽  
Author(s):  
Charles H. O'Donoghue ◽  
Eileen (Bulman) Abbott
Keyword(s):  
North America ◽  
Vascular System ◽  
Individual Preference ◽  
Squalus Acanthias ◽  
The Other ◽  
Spiny Dogfish ◽  
Considerable Confusion ◽  
Satisfactory Account ◽  
Future Work ◽  
Made In

The following investigation was commenced, in the first place, to provide information for class use, for, in spite of the fact that thousands of specimens of Squalus acanthias and S. sucklii are used every year in North America, there appears to be no satisfactory account of the blood vascular system of either species available. As the work proceeded, various problems arose which necessitated references to the conditions in other species and the preparation of more detailed dissections than are usually made in class work. It is well known that there is considerable confusion in the nomenclature employed by different authors for even some of the main vessels, and it was soon evident that this is not merely individual preference but, in part, due to a more fundamental lack of agreement as to the precise morphological significance of the vessels themselves. More recent embryological investigations by other workers have, we consider, given a key to the solution of the most important of these problems and have shown that, in so far as the blood-vessels are concerned, the Elasmobranchs lie closer to the other gnathostomatous vertebrates than is generally recognised, and indeed furnish a primitive and generalised type. The time seemed ripe, therefore, to provide a connected account of the vascular system in an Elasmobranch, viewing it in the light of the researches just referred to, and of what is known of the distribution of the various vessels in the sub-class in general. It was hoped that this would provide an epitome that would serve as a basis for future work in the sub-class, and also for comparison with the conditions in higher vertebrates.

scholarly journals Exploring the influence of the North Pacific Ocean Rossby wave sources on interannual variability of summer precipitation and surface temperature over the Northern Hemisphere.

2021 ◽  
Author(s):  
Ramon Fuentes-Franco ◽  
Torben Koenigk ◽  
David Docquier ◽  
Federico Graef ◽  
Klaus Wyser
Keyword(s):  
Pacific Ocean ◽  
North America ◽  
Surface Temperature ◽  
Northern Hemisphere ◽  
Rossby Wave ◽  
North Atlantic ◽  
Rossby Waves ◽  
The North ◽  
Northeastern Pacific ◽  
The North Atlantic

Abstract The influence of Rossby wave sources (RWS) emitted on the Northeastern Pacific Ocean in the Northern Hemisphere during summer is analysed in the ERA5 reanalysis and new large ensemble performed with the EC-Earth3 model. Using extreme years composites of precipitation, surface temperature, geopotential height, we found a causal influence of the Rossby waves generated over the Northeastern Pacific Ocean, on a global climate response. Both the reanalysis ERA5 and the EC-Earth3 model show that RWS triggers wave-like patterns arising from the upper troposphere Northeastern Pacific region. We show that an increased Rossby wave sources intensity is related with negative temperature anomalies over western North America, and positive temperature anomalies over eastern North America concurrently increased precipitation over Northern Europe during summer and sea-ice concentration decrease in the Arctic. We also show that the North Atlantic plays a very important role hindering or permitting that Rossby waves generated in the Pacific reach the Atlantic and modulate the atmospheric conditions over Europe. Such conditions were found in ERA5 and SMHI-LENS during colder and icier conditions over the North Atlantic.

Sea Surface Temperature Changes in the Northeastern Pacific Ocean during the Past 20,000 Years and Their Relationship to Climate Change in Northwestern North America

1996 ◽  
Vol 46 (1) ◽  
pp. 48-61 ◽  
Author(s):  
Ann L. Sabin ◽  
Nicklas G. Pisias
Keyword(s):  
Pacific Ocean ◽  
North America ◽  
North Pacific ◽  
Sea Surface ◽  
The Past ◽  
The North ◽  
Northeastern Pacific ◽  
Northwestern North America ◽  
The North Pacific ◽  
Continental Climate

Modern ocean–atmosphere interactions in the northeastern Pacific Ocean have a significant effect on the climate of the west coast of North America. We present radiolarian microfossil-based temperature reconstructions for the eastern North Pacific spanning the past 20,000 yr to examine possible correlations and linkages between continental climate change and changes in sea surface temperature (SST) in the northeastern Pacific Ocean on millennial time scales. The reconstructions indicate that the regional pattern of ocean circulation off the west coast of North America was further south 15,000 cal yr B.P. than it is today, and reached its present location 13,000 cal yr B.P. The North Pacific Drift and Transition Zone were further south as a result of a more southerly North Pacific high pressure cell prior to 13,000 cal yr B.P. While two continental paleoclimate records from northwestern North America show regional differences, they also can be correlated to the SST changes. A coastal site at 48°N shows similar patterns in summer temperatures, as observed in offshore marine records of SSTs. However, an inland continental record seems to reflect more-regional-scale changes in sea surface conditions showing a thermal maximum centered at 10,000 cal yr B.P which is observed in the marine transect south of 42°N. We conclude, based on the pattern of oceanographic change as reflected in radiolarian assemblages, that changes in the past latitudinal position of the North Pacific Drift played a significant role in controlling continental climate immediately to its east, as it does in the present environment. We also conclude that during the past 20,000 yr much of the evolution of oceanographic change is related to the migration of the atmospheric pressure cells (the North Pacific high and Aleutian low) of the northeastern Pacific.

Orbiniella nuda new species (Orbiniidae) and nine new records of other sedentariate polychaetous annelids from Washington and British Columbia

1974 ◽  
Vol 52 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Katharine D. Hobson
Keyword(s):  
British Columbia ◽  
New Species ◽  
Pacific Ocean ◽  
New Records ◽  
Descriptive Information ◽  
Northeastern Pacific

Orbiniella nuda, new species, is newly described from Washington. Naineris quadricuspida, Pygospio elegans, Pherusa negligens, Asclerocheilus beringianus, Euzonus williamsi, Barantolla americana, Decamastus gracilis, Mediomastus capensis, and Stygocapitella subterranea are newly recorded from Washington or from Washington and British Columbia. Most of these species have not previously been reported from the cold temperate northeastern Pacific Ocean. In addition, new descriptive information is provided for some species.

scholarly journals A Climatology of 500-hPa Closed Lows in the Northeastern Pacific Ocean, 1948–2011

2014 ◽  
Vol 53 (6) ◽  
pp. 1578-1592 ◽  
Author(s):  
Nina S. Oakley ◽  
Kelly T. Redmond
Keyword(s):  
United States ◽  
Pacific Ocean ◽  
Interannual Variability ◽  
West Coast ◽  
The United States ◽  
Western United States ◽  
The West ◽  
Reanalysis Dataset ◽  
The Pacific ◽  
Northeastern Pacific

AbstractThe northeastern Pacific Ocean is a preferential location for the formation of closed low pressure systems. These slow-moving, quasi-barotropic systems influence vertical stability and sustain a moist environment, giving them the potential to produce or affect sustained precipitation episodes along the west coast of the United States. They can remain motionless or change direction and speed more than once and thus often pose difficult forecast challenges. This study creates an objective climatological description of 500-hPa closed lows to assess their impacts on precipitation in the western United States and to explore interannual variability and preferred tracks. Geopotential height at 500 hPa from the NCEP–NCAR global reanalysis dataset was used at 6-h and 2.5° × 2.5° resolution for the period 1948–2011. Closed lows displayed seasonality and preferential durations. Time series for seasonal and annual event counts were found to exhibit strong interannual variability. Composites of the tracks of landfalling closed lows revealed preferential tracks as the features move inland over the western United States. Correlations of seasonal event totals for closed lows with ENSO indices, the Pacific decadal oscillation (PDO), and the Pacific–North American (PNA) pattern suggested an above-average number of events during the warm phase of ENSO and positive PDO and PNA phases. Precipitation at 30 U.S. Cooperative Observer stations was attributed to closed-low events, suggesting 20%–60% of annual precipitation along the West Coast may be associated with closed lows.

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