The Morphology, and Some Observations on the Population Genetics of Anisakis simplex Larvae (Nematoda: Ascaridata) from Fishes of the North Atlantic

1977 ◽  
Vol 34 (1) ◽  
pp. 105-112 ◽  
Author(s):  
Mary Beverley-Burton ◽  
O. L. Nyman ◽  
John H. C. Pippy
Keyword(s):  
Acid Phosphatase ◽  
North Atlantic ◽  
Anisakis Simplex ◽  
Clupea Harengus ◽  
Geographic Ranges ◽  
The North ◽  
The North Atlantic ◽  
Clupea Harengus Harengus ◽  
Species Frequencies

The morphology of larval Anisakis simplex in a subsample taken from Atlantic herring, Clupea harengus harengus, in the North Sea (and used in previous in vitro culture experiments) is described, with particular reference to the excretory system.The morphological similarities of these larvae from C. harengus harengus and Atlantic salmon, Salmo salar, taken in widely separated locations in the North Atlantic suggests that Anisakis larvae Type 1 is A. simplex. These findings are substantiated by studies on acid phosphatase polymorphism of the larvae and the known geographic ranges of related species. Frequencies of the acid phosphatase phenotypes varied in different sampling areas, suggesting that different populations of larval A. simplex occur in fish in the North Atlantic.

Genomic identification of Anisakis simplex isolates

1997 ◽  
Vol 71 (1) ◽  
pp. 73-75 ◽  
Author(s):  
M. Siles ◽  
C. Cuéllar ◽  
M.J. Perteguer
Keyword(s):  
Genetic Variability ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Anisakis Simplex ◽  
Merluccius Merluccius ◽  
High Genetic Variability ◽  
The North ◽  
The North Atlantic ◽  
Two Populations ◽  
Conger Conger

AbstractRAPD technique was used to differentiate individuals of Anisakis simplex obtained from Merluccius merluccius, Phycis blennoides, Conger conger and Lepidorhombus boscii, from the North Atlantic Ocean. The amplification patterns of the host DNA controls were markedly different from those obtained for the parasitic material. No variation within the same host was detected. The amplification patterns for larvae obtained from fish of the same genus were somewhat different. The amplification patterns of A. simplex isolates from M. merluccius, P. blennoides, C. conger and L. boscii, were different. These results suggest the possible existence of two populations with a considerable high genetic variability and a different adaptation to different host species.

scholarly journals Slave to the rhythm: how large-scale climate cycles trigger herring (Clupea harengus) regeneration in the North Sea

2009 ◽  
Vol 67 (3) ◽  
pp. 454-465 ◽  
Author(s):  
Joachim P. Gröger ◽  
Gordon H. Kruse ◽  
Norbert Rohlf
Keyword(s):  
North Sea ◽  
North Atlantic ◽  
Large Scale ◽  
Clupea Harengus ◽  
Traffic Light ◽  
The North ◽  
Climate Cycles ◽  
Stock Assessments ◽  
The North Sea ◽  
The North Atlantic

AbstractGröger, J. P., Kruse, G. H., and Rohlf, N. 2010. Slave to the rhythm: how large-scale climate cycles trigger herring (Clupea harengus) regeneration in the North Sea. – ICES Journal of Marine Science, 67: 454–465. Understanding the causes of variability in the recruitment of marine fish stocks has been the “holy grail” of fisheries scientists for more than 100 years. Currently, debate is ongoing about the functionality and performance of traditional stock–recruitment functions used during stock assessments. Additionally, the European Commission requires European fishery scientists to apply the ecosystem approach to fisheries in part by integrating environmental knowledge into stock assessments and forecasts. Motivated to understand better the recent years of reproductive failures of commercially valuable North Sea herring, we studied large-scale climate changes in the North Atlantic Ocean and their potential effects on stock regeneration. Applying traffic light plots and time-series (TS) analyses, it was possible not only to explain the most recent reproductive failures, but also to reconstruct the full TS of recruitment from climate cycles, indexed by the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation. A prognostic model was developed to provide predictions of herring stock changes several years in advance, allowing recruitment forecasts to be incorporated easily into risk assessments and management strategy evaluations, to promote a sustainable herring fishery in the North Sea. Insights gained from the analysis permit reinterpretation of the sharp decline in the North Sea herring stocks in the 1970s.

scholarly journals Environmental influences on Norwegian spring-spawning herring (Clupea harengus L.) larvae reveal recent constraints in recruitment success

2020 ◽  
Author(s):  
Maik Tiedemann ◽  
Richard D M Nash ◽  
Erling K Stenevik ◽  
Martina H Stiasny ◽  
Aril Slotte ◽  
...  
Keyword(s):  
North Atlantic ◽  
Environmental Conditions ◽  
Elevated Temperatures ◽  
Life Stage ◽  
Additive Models ◽  
Clupea Harengus ◽  
Positive Temperature ◽  
Slow Increase ◽  
The North ◽  
The North Atlantic

Abstract The lack of any abundant recruiting year class of Norwegian spring-spawning (NSS) herring between 2005 and 2015 contributed to an approximate reduction of 40% in the spawning-stock biomass since 2009, i.e. from 7 to 4 million tonnes. Warming of the North Atlantic is suggested to contribute to this reduction in recruitment. In the past, a warm phase induced by a positive Atlantic Multidecadal Oscillation (AMO) in the North Atlantic was positively correlated to the NSS herring stock size. Recent unprecedented ocean warming in the Norwegian Sea ecosystem, besides elevated temperatures due to a positive AMO, seems to be outside optimal environmental conditions for early life history stages of NSS herring. We analysed 28 years of survey data using generalized additive models to reconstruct environmental conditions for drifting yolksac and preflexion stage larvae. Our results indicate that strong recruitment years were more likely when the larvae occurred simultaneously with a negative AMO during positive temperature anomalies. The transition from yolksac stages towards preflexion stages occurred while there was a slow increase in water temperature during the larval drift. Weak recruitment years generally occurred when larvae experienced elevated temperatures during the life stage transition under a positive AMO. These results augment evidence that the historical positive relationship between AMO and stock dynamics is reversed between 1988 and 2015. Albeit not implying any specific mechanistic biological interactions, we can assume that the unprecedented warming has modified the ecosystem drivers that negatively affect drifting larvae. Since 2016, the North Atlantic is shifting into a negative AMO phase, possibly resulting in the 10-year recruitment suppression of NSS herring ending soon.

The Currents of the North Atlantic

1892 ◽  
Vol 34 (872supp) ◽  
pp. 13940-13941
Author(s):  
Richard Beynon
Keyword(s):  
North Atlantic ◽  
The North ◽  
The North Atlantic

NATO adaptation to current challenges and mechanisms of Ukraine’s cooperation with the North Atlantic Treaty Organization

2019 ◽  
pp. 73-81
Author(s):  
Oleh Poshedin
Keyword(s):  
North Atlantic ◽  
Task Force ◽  
Response Force ◽  
Cyber Attack ◽  
Adaptation Measures ◽  
Joint Force ◽  
Security Environment ◽  
The North ◽  
The North Atlantic ◽  
Area Of Influence

The purpose of the article is to describe the changes NATO undergoing in response to the challenges of our time. Today NATO, as a key element of European and Euro-Atlantic security, is adapting to changes in the modern security environment by increasing its readiness and ability to respond to any threat. Adaptation measures include the components required to ensure that the Alliance can fully address the security challenges it might face. Responsiveness NATO Response Force enhanced by developing force packages that are able to move rapidly and respond to potential challenges and threats. As part of it, was established a Very High Readiness Joint Task Force, a new Allied joint force that deploy within a few days to respond to challenges that arise, particularly at the periphery of NATO’s territory. NATO emphasizes, that cyber defence is part of NATO’s core task of collective defence. A decision as to when a cyber attack would lead to the invocation of Article 5 would be taken by the North Atlantic Council on a case-by-case basis. Cooperation with NATO already contributes to the implementation of national security and defense in state policy. At the same time, taking into account that all decision-making in NATO based on consensus, Ukraine’s membership in the Alliance quite vague perspective. In such circumstances, in Ukraine you often can hear the idea of announcement of a neutral status. It is worth reminding that non-aligned status did not save Ukraine from Russian aggression. Neutral status will not accomplish it either. All talks about neutrality and the impossibility of Ukraine joining NATO are nothing but manipulations, as well as recognition of the Ukrainian territory as Russian Federation area of influence (this country seeks to sabotage the Euro-Atlantic movement of Ukraine). Think about it, Moldova’s Neutrality is enshrined in the country’s Constitution since 1994. However, this did not help Moldova to restore its territorial integrity and to force Russia to withdraw its troops and armaments from Transnistria.

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