scholarly journals Population genetics meets phylogenetics: new insights into the relationships among members of the genus Euthynnus (family Scombridae)

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Judith Ollé ◽  
Laura Vilà-Valls ◽  
Jaime Alvarado-Bremer ◽  
Genoveva Cerdenares ◽  
Thuy Yen Duong ◽  
...  
Keyword(s):  
North Atlantic ◽  
Genetic Divergence ◽  
East Atlantic ◽  
North West ◽  
North East ◽  
The North ◽  
Worldwide Distribution ◽  
Allopatric Species ◽  
The North Atlantic ◽  
High Level

AbstractEuthynnus (family Scombridae) is a genus of marine pelagic fish species with a worldwide distribution that comprises three allopatric species: E. alletteratus, E. affinis and E. lineatus. All of them targeted by artisanal and commercial fisheries. We analyzed 263 individuals from Atlantic and Pacific Oceans using two genetic markers, the mtDNA Control Region (350 bp) and nuclear calmodulin (341 bp). The results obtained challenge the phylogeny of this group. We found a deep genetic divergence, probably at species level, within E. alletteratus, between the North Atlantic-Mediterranean and the Tropical East Atlantic. This deep genetic divergence was tested with several species delimitation methods. This complete phylogeographic association between the North Atlantic and the Tropical East Atlantic support the hypothesis of two cryptic species. In addition, population genetic heterogeneity was detected between the North East Atlantic–Mediterranean and North West Atlantic regions. Our results indicate two scales of differentiation in what is currently considered a single population. Accordingly, for management purposes, the populations of E. alletteratus, should be divided into a minimum of three management units. On the other hand, the high level of differentiation found in E. alletteratus contrasts with the shallow genetic divergence of E. affinis and E. lineatus.

scholarly journals Large-scale changes of the semidiurnal tide along North Atlantic coasts from 1846 to 2018

Ocean Science ◽  
2021 ◽  
Vol 17 (1) ◽  
pp. 17-34
Author(s):  
Lucia Pineau-Guillou ◽  
Pascal Lazure ◽  
Guy Wöppelmann
Keyword(s):  
Sea Level ◽  
North Atlantic ◽  
Large Scale ◽  
Low Frequency ◽  
Underlying Mechanism ◽  
East Atlantic ◽  
North West ◽  
North East ◽  
The North ◽  
The North Atlantic

Abstract. We investigated the long-term changes of the principal tidal component M2 along North Atlantic coasts, from 1846 to 2018. We analysed 18 tide gauges with time series starting no later than 1940. The longest is Brest with 165 years of observations. We carefully processed the data, particularly to remove the 18.6-year nodal modulation. We found that M2 variations are consistent at all the stations in the North-East Atlantic (Cuxhaven, Delfzijl, Hoek van Holland, Newlyn, Brest), whereas some discrepancies appear in the North-West Atlantic. The changes started long before the 20th century and are not linear. The secular trends in M2 amplitude vary from one station to another; most of them are positive, up to 2.5 mm/yr at Wilmington since 1910. Since 1990, the trends switch from positive to negative values in the North-East Atlantic. Concerning the possible causes of the observed changes, the similarity between the North Atlantic Oscillation and M2 variations in the North-East Atlantic suggests a possible influence of the large-scale atmospheric circulation on the tide. Our statistical analysis confirms large correlations at all the stations in the North-East Atlantic. We discuss a possible underlying mechanism. A different spatial distribution of mean sea level (corresponding to water depth) from one year to another, depending on the low-frequency sea-level pressure patterns, could impact the propagation of the tide in the North Atlantic basin. However, the hypothesis is at present unproven.

scholarly journals Climate-scale changes of the semidiurnal tide over the North Atlantic coasts from 1846 to 2018

2020 ◽  
Author(s):  
Lucia Pineau-Guillou ◽  
Pascal Lazure ◽  
Guy Wöppelmann
Keyword(s):  
North Atlantic ◽  
Large Scale ◽  
Low Frequency ◽  
Underlying Mechanism ◽  
East Atlantic ◽  
North West ◽  
North East ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation

Abstract. We investigated the long-term changes of the principal tidal component M2 over the North Atlantic coasts, from 1846 to 2018. We analysed 9 tide gauges with time series starting no later than 1920. The longest is Brest with 165 years of observations. We carefully processed the data, particularly to remove the 18.6-year nodal modulation. We found that M2 variations are consistent at all the stations in the North East Atlantic (Newlyn, Brest, Cuxhaven), whereas some discrepancies appear in the North West Atlantic. The changes started long before the XXth century, and are not linear. The trends vary from a station to another; they are overall positive, up to 0.7 mm/yr. Since 1990, the trends switch from positive to negative values. Concerning the possible causes of the observed changes, the similarity between the North Atlantic Oscillation and M2 variations in the North East Atlantic suggests a possible influence of the large-scale atmospheric circulation on the tide. We discuss a possible underlying mechanism. A different spatial distribution of water heights from one year to another, depending on the low-frequency sea-level pressure patterns, could impact the propagation of the tide in the North Atlantic basin. However, the hypothesis is at present unproven.

A new species of amphipod, Megamphopus katagani sp. nov. (Crustacea: Peracarida: Photidae) from the Sea of Marmara (Turkey), with a key to the species of Megamphopus in the North Atlantic, Mediterranean and associated Seas

Zootaxa ◽  
2011 ◽  
Vol 2791 (1) ◽  
pp. 63 ◽  
Author(s):  
KEREM BAKIR ◽  
MURAT SEZGIN ◽  
ALAN A. MYERS
Keyword(s):  
New Species ◽  
North Atlantic ◽  
Sea Of Marmara ◽  
East Atlantic ◽  
North East ◽  
The North ◽  
The North Atlantic ◽  
A New Species

A new species of amphipod, Megamphopus katagani sp. nov., is described from the sea of Marmara (Turkey). A key to the species of Megamphopus known from the North-East Atlantic, Mediterranean and associated seas is provided.

Ophlitaspongia and Ophlitaspongia papilla reinstated, and a new species of Ophlitaspongia described (Porifera: Demospongiae: Microcionidae)

1999 ◽  
Vol 79 (4) ◽  
pp. 609-620 ◽  
Author(s):  
C.M. Howson ◽  
S.J. Chambers
Keyword(s):  
New Species ◽  
North Atlantic ◽  
Deep Water ◽  
The Other ◽  
East Atlantic ◽  
Halichondria Panicea ◽  
North East ◽  
The North ◽  
The North Atlantic ◽  
A New Species

A new species of Ophlitaspongia (Porifera: Microcionidae) from wave-exposed sublittoral rock in the north-east Atlantic is described and compared to the two other species recorded from the genus in the north-east Atlantic. The species known as Ophlitaspongia seriata is considered to be a junior synonym of Halichondria panicea. Consequently, the name O. papilla has been reinstated. The other recorded species O. basifixa, is from deep water. Ophlitaspongia basifixa has characters which differentiate it from Ophlitaspongia sp. nov. The genus Ophlitaspongia has been separated from related genera and reinstated for species in the North Atlantic.

Latitudinal Displacements of the Gulf Stream and the Abundance of Plankton in the North-East Atlantic

1992 ◽  
Vol 72 (4) ◽  
pp. 919-921 ◽  
Author(s):  
A. H. Taylor ◽  
J. M. Colebrook ◽  
J. A. Stephens ◽  
N. G. Baker
Keyword(s):  
Time Series ◽  
North Atlantic ◽  
Gulf Stream ◽  
Storm Tracks ◽  
British Isles ◽  
East Atlantic ◽  
North East ◽  
The North ◽  
The North Atlantic ◽  
North Wall

An earlier time-series of the annual mean latitude of the north wall of the Gulf Stream is updated to give a series of values from 1966 to 1990. The trend is similar to those seen in plankton from the Continuous Plankton Recorder Survey around the British Isles. This connection may reflect the displacement of storm tracks across the North Atlantic.

Management and Developement of Fisheries in the North Atlantic

1973 ◽  
Vol 30 (12) ◽  
pp. 2402-2418 ◽  
Author(s):  
G. Möcklinghoff
Keyword(s):  
Fish Species ◽  
North Atlantic ◽  
Mesh Size ◽  
Fishing Effort ◽  
Conceptual Basis ◽  
East Atlantic ◽  
International Council ◽  
North East ◽  
The North ◽  
The North Atlantic

The "conventional" fish species of the North Atlantic are mostly being fully utilized or nearly so, some having been overexploited in recent years. Recommendations for management are made by the International Commission for the Northwest Atlantic Fisheries (ICNAF) and the North East Atlantic Fisheries Commission (NEAFC). The factual and conceptual basis for management is provided by the scientists of many nations, coordinated by ICNAF and by the International Council for the Exploration of the Sea (ICES). The need in nearly every major North Atlantic fishery is to limit fishing effort, which in practical terms means allocating quotas to states. Such action has been initiated by ICNAF and is under active consideration by NEAFC. The process would have been easier if it had been begun a few years earlier, before several major stocks became depressed, but since new ground is being broken internationally the delay was almost inevitable. Regulations of mesh size in trawls have been in force in both areas for some years. These were successful in providing a greater yield from each year-class of groundfish as it appeared, but could not by themselves ensure a breeding stock adequate for optimum reproduction. Problems of allocation of quotas, of enforcement, and of national claims for the extension of exclusive fishing zones will require continued discussion and goodwill among the nations in the years ahead.

Lampropidae (Crustacea: Cumacea) from the deep north-east Atlantic and the North Sea, with two new species of Hemilamprops and Mesolamprops

2007 ◽  
Vol 87 (5) ◽  
pp. 1191-1200 ◽  
Author(s):  
Salma H. Shalla ◽  
John D.D. Bishop
Keyword(s):  
New Species ◽  
North Sea ◽  
North Atlantic ◽  
First Record ◽  
East Atlantic ◽  
North East ◽  
The North ◽  
The North Sea ◽  
The North Atlantic ◽  
A New Species

Material collected during surveys of the Atlantic Frontier Margin (north-east Atlantic) in 1996, 1998, 2000 and 2002 includes ten species of the cumacean family Lampropidae belonging to three genera. A new species of the genus Hemilamprops, H. pterini, is described. Hemilamprops cristatus is partially re-illustrated from specimens sent to A.M. Norman by G.O. Sars. A key to the North Atlantic species of Hemilamprops is provided. A new species of the genus Mesolamprops, M. hartleyi, is described from the Atlantic Frontier Margin and the North Sea. The first record of Mesolamprops denticulatus from the Atlantic is reported. A key to the species of Mesolamprops is provided. Two species of the genus Platysympus were also found. A list of other lampropid species found in the Atlantic Frontier Margin is given.

scholarly journals New and little known species of Lepechinella (Crustacea, Amphipoda, Lepechinellidae) and an allied new genus Lepesubchela from the North Atlantic

2015 ◽  
Author(s):  
Per-Otto Johansen ◽  
Wim Vader
Keyword(s):  
New Species ◽  
North Atlantic ◽  
Related Species ◽  
New Genus ◽  
Related Genus ◽  
East Atlantic ◽  
North East ◽  
The North ◽  
The North Atlantic

New species of Lepechinella, L. norvegica sp. nov. and L. victoriae sp. nov., from the North East Atlantic are described together with the new, closely related genus and species Lepesubchela christinae gen. et sp. nov. Lepechinella arctica Schellenberg, 1926 from north of Spitsbergen and Lepechinella schellenbergi Stephensen, 1944 from Greenland are redescribed. A key to the species of Atlantic and Arctic Lepechinella is provided. Descriptions of taxonomic characters from related species in the Atlantic and Arctic are discussed.

scholarly journals A review of Norwegian streptaster-bearing Astrophorida (Porifera: Demospongiae: Tetractinellida), new records and a new species

Zootaxa ◽  
2012 ◽  
Vol 3253 (1) ◽  
pp. 1 ◽  
Author(s):  
PACO CÁRDENAS ◽  
HANS TORE RAPP
Keyword(s):  
Cytochrome C ◽  
Coi Gene ◽  
East Atlantic ◽  
North West ◽  
North East ◽  
The North ◽  
New Material ◽  
Distinct Morphology ◽  
Partial Fragment ◽  
A New Species

We report and describe new material of streptaster-bearing Astrophorida sponges collected in Norway: Characellapachastrelloides, Pachastrella nodulosa sp. nov., Poecillastra compressa, Vulcanella cf. aberrans, Thenea abyssorum,Thenea levis, Thenea muricata and Thenea valdiviae. Because many of these species were described in the end of the 19thcentury their original descriptions are often incomplete. The Norwegian specimens are the basis for a revision of themorphology, taxonomy and distribution of these species. These are the first records of C. pachastrelloides and V. cf.aberrans from the Norwegian coast. Pachastrella nodulosa sp. nov. differs from Pachastrella monilifera by (i) its knobbysurface and (ii) the absence of large oxeas, (iii) its amphiasters have on average less actines and are less spiny, finally (iv)microxeas are rare and with a distinct morphology (although there is some doubt concerning their origin). In the presentstudy, Characella tuberosa (from South Africa), Pachastrella abyssi (from the North-West Atlantic) and Thenea schmidti(from the North-East Atlantic) are resurrected. To help their future identifications, all the Norwegian species describedwere associated with DNA barcodes: a cytochrome c oxidase subunit I (COI) gene partial fragment and/or a 28S ribosomalgene partial fragment (C1–D2 domains). Furthermore, a key to the streptaster-bearing Astrophorida of the North-East Atlantic and the Mediterranean Sea is also given (lithistids not included).Nous signalons la présence et décrivons des spécimens d’Astrophorida à streptasters nouvellement récoltés en Norvège:Characella pachastrelloides, Pachastrella nodulosa sp. nov., Poecillastra compressa, Vulcanella cf. aberrans, Theneaabyssorum, Thenea levis, Thenea muricata et Thenea valdiviae. Plusieurs de ces espèces ont été décrites de manièreincomplète à la fin du 19ème siècle. Les spécimens norvégiens sont l’occasion de réviser la morphologie, la taxonomie etla distribution de ces espèces. C’est la première fois que C. pachastrelloides et V. cf. aberrans sont mentionnés sur la côtenorvégienne. Pachastrella nodulosa sp. nov. se distingue de Pachastrella monilifera par (i) sa surface noduleuse et (ii)l’absence de grands oxes, (iii) ses amphiasters ont en moyenne moins d’actines et sont moins épineux, enfin (iv) lesmicroxes sont rares et ont une morphologie distincte (bien qu’il y ait encore des doutes sur leur origine). Au cours de notreétude, Characella tuberosa (d’Afrique du Sud), Pachastrella abyssi (de l’Atlantique Nord-Ouest) et Thenea schmidti (del’Atlantique Nord-Est) sont ressuscités. Afin d’aider leurs identifications futures, toutes les espèces de Norvège décritesont été associées à des code-barres moléculaires: un fragment partiel du gène de la sous-unité I du cytochrome c oxydase(COI) et/ou un fragment partiel du gène ribosomique 28S (domaines C1-D2). De plus, une clé pour identifier les Astrophorida à streptasters de l’Atlantique Nord-Est et de Méditerrannée est également fournie (lithistides non inclus).

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