Meristic Analyses of Atlantic Mackerel, Scomber scombrus, from the North American Coastal Populations

1969 ◽  
Vol 26 (9) ◽  
pp. 2537-2540 ◽  
Author(s):  
K. T. MacKay ◽  
E. T. Garside
Keyword(s):  
Atlantic Ocean ◽  
Growth Rates ◽  
Biochemical Evidence ◽  
Atlantic Mackerel ◽  
Scomber Scombrus ◽  
Dorsal Fin ◽  
The North ◽  
Breeding Populations ◽  
Fin Rays ◽  
Genetic Continuity

Mean counts of vertebrae, of anal and soft dorsal fin rays, and of peduncular finlets were identical in samples of Atlantic mackerel, Scomber scombrus, from the northern and southern breeding populations in the northwest Atlantic Ocean. This information, together with growth rates and biochemical evidence from the literature, suggests that although the populations occupy separate spawning regions there is sufficient exchange of individuals at other seasons to maintain considerable genetic continuity.

Eggs and Larvae of Northern Sand Lance (Ammodytes dubius) from the Scotian Shelf

1972 ◽  
Vol 29 (12) ◽  
pp. 1667-1671 ◽  
Author(s):  
J. S. Scott
Keyword(s):  
Growth Rates ◽  
Scotian Shelf ◽  
Sand Lance ◽  
Yellowtail Flounder ◽  
Limanda Ferruginea ◽  
Dorsal Fin ◽  
The North ◽  
Mean Diameter ◽  
Fin Rays ◽  
Eggs And Larvae

Eggs from stomachs of yellowtail flounder (Limanda ferruginea) from Emerald Bank, south of Nova Scotia, were identified as those of northern sand lance, Ammodytes dubius. They were larger than those of other Ammodytes species, with a mean diameter of 1.05 mm. Ovarian eggs from ripe A. dubius were smaller (mean diameter 0.7 mm) with a unimodal distribution of egg diameters, indicating a single spawning each season.Larvae were widespread and abundant on the Scotian Shelf from February to April. They hatched at about 4-mm length and grew to about 25-mm length between February and May on Emerald Bank. Growth rates decreased to the north. Numbers and distribution of melanophores changed with larval length, but showed no differences in number at given length between geographical areas. Change in numbers of anal, caudal, and dorsal fin rays followed a pattern similar to that of corresponding melanophores.

Effects of variable mean target strength on estimates of abundance: the case of Atlantic mackerel (Scomber scombrus)

2016 ◽  
Vol 74 (3) ◽  
pp. 822-831 ◽  
Author(s):  
Ben Scoulding ◽  
Sven Gastauer ◽  
David N. MacLennan ◽  
Sascha M. M. Fässler ◽  
Phillip Copland ◽  
...  
Keyword(s):  
Stock Assessment ◽  
Target Strength ◽  
Fish School ◽  
Acoustic Data ◽  
Atlantic Mackerel ◽  
Scomber Scombrus ◽  
North East ◽  
The North ◽  
Frequency Split ◽  
Abundance And Distribution

Atlantic mackerel Scomber scombrus is a small pelagic, migratory fish which supports commercial fisheries. These fish school and are detectable using echosounders, yet fishery-independent estimates of their abundance in the North East Atlantic do not consider acoustic data. Accurate estimates of mean target strength (TS) are presently limiting echo-integration surveys from providing useful estimates of Atlantic mackerel abundance and distribution. This study provides TS estimates for in situ mackerel from multi-frequency split-beam echosounder measurements. TS equals −52.79 dB at 18 kHz, −59.60 dB at 38 kHz, −55.63 dB at 120 kHz, and −53.58 dB at 200 kHz, for a mean mackerel total length = 33.3 cm. These values differ from those currently assumed for this species in analyses of acoustic survey data. We investigate the sensitivity of acoustically estimated mackerel biomass around the Shetland Islands, Scotland, in 2014, to various estimates of TS. Confidence limits were obtained using geostatistics accounting for coverage and spatial autocorrelation. Stock biomasses, estimated from 38 and 200 kHz data, differed by 10.5%, and stock distributions were similar to each other and to the estimates from an independent stock assessment. Because mackerel backscatter at 38 kHz is dominated by echoes from the flesh and may have similarities to echoes from fish with swimbladders, and backscatter at 200 kHz is dominated by relatively stable echoes from the backbone, we recommend using 200 kHz data for estimates of Atlantic mackerel biomass.

Usefulness of Fourier Analysis of Otolith Shape for Atlantic Mackerel (Scomber scombrus) Stock Discrimination

1991 ◽  
Vol 48 (2) ◽  
pp. 296-302 ◽  
Author(s):  
Martin Castonguay ◽  
Patrick Simard ◽  
Pierre Gagnon
Keyword(s):  
Stock Structure ◽  
Discriminant Functions ◽  
Position Effects ◽  
Northwest Atlantic ◽  
Otolith Shape ◽  
Atlantic Mackerel ◽  
Scomber Scombrus ◽  
The North ◽  
Stock Discrimination ◽  
The North Sea

We compared shapes of Atlantic mackerel (Scomber scombrus) sagittae between the two contingents (i.e. spawning groups) from the Northwest Atlantic and between the stocks from the Northwest Atlantic and the North Sea to evaluate whether otolith shape could differentiate between the two contingents in a mixed fishery. We quantified shapes with the Fourier series, an objective and rapid method which decomposes a shape's outline into a series of sinusoids. To determine a correct way to compare contingents/stocks, we first assessed four intracontingent effects on otolith shapes. Age and year-class effects were significant, while sex and bilateral position effects were not. This temporal instability in shapes indicates that confounding effects of age and year-class on otolith shapes need to be assessed carefully before drawing conclusions on stock structure. It also shows that comparative studies of otolith shapes with Fourier descriptors are not useful for mackerel contingent discrimination. The power of discriminant functions to correctly classify test mackerel samples separated by age and sampling year, on the basis of otolith shape, was better for comparisons between the stocks than for those between the contingents.

scholarly journals Description of a new species of Echiodon (Teleostei: Carapidae) from the South Atlantic Ocean

Zootaxa ◽  
2005 ◽  
Vol 809 (1) ◽  
pp. 1 ◽  
Author(s):  
M. ERIC ANDERSON
Keyword(s):  
New Species ◽  
Atlantic Ocean ◽  
Adult Male ◽  
South Atlantic ◽  
South Atlantic Ocean ◽  
Swim Bladder ◽  
Dorsal Fin ◽  
Fin Rays ◽  
A New Species ◽  
Pectoral Fin Rays

A new species of pearlfish, Echiodon atopus, is described from a single adult male, 176 mm TL, collected off Inaccessible Island, Tristan da Cunha Group, South Atlantic Ocean. It is characterized by its high, equal D 30 and A 30 counts (46 rays each), 7 anal rays anterior to the dorsal-fin origin, 38 precaudal vertebrae, 18 pectoral-fin rays and ventral swim bladder tunic ridges. It was caught in a bottom trawl over a deep lava-reef structure, but may be pelagic.

scholarly journals Changes in the spawning distribution and biomass of Atlantic mackerel (Scomber scombrus) in the western Atlantic Ocean over 4 decades

2020 ◽  
Vol 118 (2) ◽  
pp. 120-134
Author(s):  
David E. Richardson ◽  
Lauren Carter ◽  
Kiersten L. Curti ◽  
Katrin E. Marancik ◽  
Martin Castonguay
Keyword(s):  
Atlantic Ocean ◽  
Western Atlantic ◽  
Atlantic Mackerel ◽  
Scomber Scombrus ◽  
Western Atlantic Ocean

scholarly journals The genetic composition of feeding aggregations of the Atlantic mackerel (Scomber scombrus) in the central north Atlantic: a microsatellite loci approach

2020 ◽  
Vol 77 (2) ◽  
pp. 604-612
Author(s):  
Davið Gíslason ◽  
Sarah J Helyar ◽  
Guðmundur J Óskarsson ◽  
Guðbjörg Ólafsdóttir ◽  
Aril Slotte ◽  
...  
Keyword(s):  
North Atlantic ◽  
Microsatellite Loci ◽  
Migration Patterns ◽  
Fish Stocks ◽  
North West ◽  
Atlantic Mackerel ◽  
Scomber Scombrus ◽  
The North ◽  
Specific Contribution ◽  
Impacts Of Climate Change

Abstract The impacts of climate change on marine ecosystems can be seen in the changing distribution, migration, and abundance of species in the oceans. For some species this changing environment may be beneficial and can support population expansions. In the northeast Atlantic (NEA), the Atlantic mackerel (Scomber scombrus) is undergoing an increase in stock size accompanied by changing summer migration patterns, which have resulted in an expansion further north and north west than previously recorded. This study uses microsatellite loci to confirm the differentiation among NEA and northwest Atlantic (NWA) mackerel spawning populations and to assess the level of structuring within these populations. In addition, to enable population-specific exploitation rates to be factored into fisheries management, we identified the origin of individuals composing the expanding feeding aggregations in the central north Atlantic (Greenland, Iceland, Faroes), with all aggregations tested originating from spawning populations in the NEA. This study showed that microsatellite loci were useful to assess the contribution of NEA and NWA populations to mixed feeding aggregations across the north Atlantic for large pelagic fish stocks but were not powerful enough to evaluate the specific contribution of known stocks within NEA and NWA.

scholarly journals Temperature constraints shaped the migration routes of mackerel (Scomber scombrus) in the Black Sea

2017 ◽  
Vol 58 (2) ◽  
pp. 337-344 ◽  
Author(s):  
Daniel Pauly ◽  
Çetin Keskin
Keyword(s):  
Black Sea ◽  
North Atlantic ◽  
The Black Sea ◽  
Seasonal Temperature ◽  
Migration Routes ◽  
Atlantic Mackerel ◽  
Scomber Scombrus ◽  
The North ◽  
And Migration ◽  
Induced Changes

Conventional narratives explain fish migrations in term of requirements (food, mates, habitats, etc.), with adequate temperatures being optional. Here, using the example of a (commercially extinct) stock of Black Sea mackerel (Scomber scombrus), we suggest that seasonal migrations are driven by seasonal temperature cycles. Therein, temperature acts as a constraint determining where the fish can be at any given time, and not a one of several factors which they would consider when choosing between alternative migration routes. Generalizing, we suggest that temperature should generally be an explicit part of hypotheses about the migratory behaviours of marine fishes. For illustration of what may occur when this is not the case, it is suggested that the non-consideration of temperature in a model of North Atlantic mackerel migration may have led, among the researchers concerned, to a sense of complacency with respect to the climate change-induced changes in the phenology of this fish in the North Atlantic, whose distribution and migration are misleadingly seen as “stochastic”.

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