scholarly journals Mitochondrial D-loop DNA analyses of Norway lobster (Nephrops norvegicus) reveals genetic isolation between Atlantic and East Mediterranean populations

2018 ◽  
Vol 99 (4) ◽  
pp. 933-940 ◽  
Author(s):  
Jeanne Gallagher ◽  
John A. Finarelli ◽  
Jónas P. Jonasson ◽  
Jens Carlsson
Keyword(s):  
Population Level ◽  
Genetic Isolation ◽  
East Mediterranean ◽  
Nephrops Norvegicus ◽  
Mediterranean Populations ◽  
North East ◽  
The North ◽  
Species Population ◽  
D Loop ◽  
Coi Sequences

AbstractNephrops norvegicus is a commercially valuable demersal fisheries species. Relatively little is understood about this species’ population dynamics across its distribution with previous mitochondrial and microsatellite studies failing to identify significant population-level differentiation. In this study, sequence variation in the mitochondrial (mtDNA) D-loop was analysed from samples across the distribution range, and compared with COI sequences for this species retrieved from GenBank. Analysis of a 375 bp fragment of the D-loop revealed significant genetic differentiation between samples from the North-east Atlantic and the east Mediterranean (FST = 0.107, P < 0.001). Tau (τ), theta (θ0 and θ1) and Fu's FS values suggest the species spread between 10,500 to 19,000 ybp and subsequently expanded rapidly across the Atlantic.

scholarly journals Mitochondrial D-loop DNA analyses of Norway Lobster (Nephrops norvegicus) reveals genetic isolation between Atlantic and Mediterranean populations

2018 ◽  
Author(s):  
Jeanne Gallagher ◽  
John A. Finarelli ◽  
Jónas P. Jonasson ◽  
Jens Carlsson
Keyword(s):  
Sequence Variation ◽  
Population Level ◽  
Genetic Isolation ◽  
East Mediterranean ◽  
Range Analysis ◽  
Nephrops Norvegicus ◽  
Mediterranean Populations ◽  
Norway Lobster ◽  
Species Population ◽  
D Loop

Nephrops norvegicus is a commercially valuable demersal fisheries species. Relatively little is understood about this species’ population dynamics across its distribution with previous mitochondrial and microsatellite studies failing to identify significant population-level differentiation. In this study, sequence variation in the mitochondrial (mtDNA) D-loop was analysed from samples across the distribution range. Analysis of a 375bp fragment of the D-loop revealed significant genetic differentiation between samples from the northeast Atlantic and the East Mediterranean (FST = 0.107, P<0.001). Tau (τ), theta (θ0 and θ1) and Fu’s Fs values suggest the species spread between 10,500 to 19,000 ybp and subsequently expanded rapidly across the Atlantic.

Body condition variation of wild rabbit population in the north-east Mediterranean island of Lemnos — Greece

2014 ◽  
Vol 63 (2) ◽  
pp. 87-94 ◽  
Author(s):  
Vasileios J. Kontsiotis ◽  
Dimitrios E. Bakaloudis ◽  
Apostolos C. Tsiompanoudis ◽  
Panteleimon Xofis
Keyword(s):  
Body Condition ◽  
Wild Rabbit ◽  
East Mediterranean ◽  
Rabbit Population ◽  
North East ◽  
The North ◽  
Mediterranean Island

scholarly journals Ovary resorption in the Norway lobster (Nephrops norvegicus) and its possible causes with special reference to sperm storage

2020 ◽  
Vol 74 (1) ◽  
Author(s):  
Carola Becker ◽  
Jaimie T. A. Dick ◽  
E. Mánus Cunningham ◽  
Mathieu Lundy ◽  
Ewen Bell ◽  
...  
Keyword(s):  
North Sea ◽  
Demographic Data ◽  
Irish Sea ◽  
Natural Phenomenon ◽  
Nephrops Norvegicus ◽  
North East ◽  
The North ◽  
Norway Lobster ◽  
The North Sea ◽  
Reproductive Cycles

Abstract The Norway lobster, Nephrops norvegicus, is an important fisheries species in the North-East Atlantic area. In some circumstances, mature females of Nephrops norvegicus can resorb their ovary rather than completing spawning, but the implications of this phenomenon to reproductive biology and fisheries sustainability are not known. To understand after effects of ovary resorption, we studied long-term demographic data sets (1994–2017) collected from the western Irish Sea and the North Sea. Our considerations focused on potential correlations among the frequency of resorption, female insemination, and body size of resorbing females. Resorption was continuously rare in the western Irish Sea (less than 1%); whereas much higher rates with considerable year-to-year variation were observed in the North Sea (mean 9%). Resorption started in autumn after the spawning season (summer) had passed. The frequency stayed high throughout winter and declined again in spring. As sperm limitation can occur in male-biased fisheries, we expected a lack of insemination could be responsible for resorption, but affected females were indeed inseminated. Resorbing females were significantly larger than other sexually mature females in the North Sea, but the opposite trend was observed in the western Irish Sea. It is therefore possible that other, environmental factors or seasonal shifts, may trigger females to resorb their ovaries instead of spawning. Resorption may as well represent a natural phenomenon allowing flexibility in the periodicity of growth and reproduction. In this sense, observations of annual versus biennial reproductive cycles in different regions may be closely linked to the phenomenon of ovary resorption.

Feeding of tub gurnard Chelidonichthys lucerna (Scorpaeniformes: Triglidae) in the north-east Mediterranean

2011 ◽  
Vol 92 (3) ◽  
pp. 605-612 ◽  
Author(s):  
Marco Stagioni ◽  
Stefano Montanini ◽  
Maria Vallisneri
Keyword(s):  
Diet Composition ◽  
Foraging Behaviour ◽  
Adriatic Sea ◽  
Feeding Habits ◽  
Feeding Activity ◽  
Stomach Contents ◽  
East Mediterranean ◽  
North East ◽  
The North ◽  
Important Prey

The stomach contents of 1096 specimens of Chelidonichthys lucerna were examined in order to analyse their diet composition according to fish size, sex, depth and season. Sampling was carried out from May 2005 to March 2007 during several bottom trawl surveys in the Adriatic Sea (north-east Mediterranean). Feeding activity was more intense in juveniles than in adults. The most important prey was Crustacea (mainly Decapoda: Brachyura, such as Goneplax rhomboides, Liocarcinus spp., Philocheras spp.) and Teleostei (mainly European anchovy Engraulis encrasicolus and black goby Gobius niger). There was no difference between male and female diet. Feeding habits varied with size, with fish dominating the stomach contents of larger specimens. Finally, fish increased in winter and crustaceans in summer. Chelidonichthys lucerna shows a generalist and opportunistic foraging behaviour, preying mainly epibenthic and nectobenthic organisms.

scholarly journals Long Term Post-Fire Vegetation Dynamics in North-East Mediterranean Ecosystems. The Case of Mount Athos Greece

Fire ◽  
2021 ◽  
Vol 4 (4) ◽  
pp. 92
Author(s):  
Panteleimon Xofis ◽  
Peter G. Buckley ◽  
Ioannis Takos ◽  
Jonathan Mitchley
Keyword(s):  
Vegetation Dynamics ◽  
Mediterranean Region ◽  
Mediterranean Ecosystems ◽  
Climatic Conditions ◽  
East Mediterranean ◽  
Northern Greece ◽  
North East ◽  
The North ◽  
Disturbance Factor

Fire is an ecological and disturbance factor with a significant historical role in shaping the landscape of fire-prone environments. Despite the large amount of literature regarding post-fire vegetation dynamics, the north-east Mediterranean region is rather underrepresented in the literature. Studies that refer to the early post fire years and long term research are rather scarce. The current study is conducted in the socially and geographically isolated peninsula of Mount Athos (Holly Mountain) in northern Greece, and it studies vegetation dynamics over a period of 30 years since the last fire. Field data were collected 11 years since the event and were used to identify the present plant communities in the area, using TWINSPAN, and the factors affecting their distribution using CART. Four Landsat (TM, ETM, OLI) images are employed for the calculation of NDVI, which was found effective in detecting the intercommunity variation in the study area, and it is used for long term monitoring. The study includes four communities, from maquis to forest which are common in the Mediterranean region covering a wide altitudinal range. The results suggest that fire affects the various communities in a different way and their recovery differs significantly. While forest communities recover quickly after fire, maintaining their composition and structure, the maquis communities may need several years before reaching the pre-fire characteristics. The dry climatic conditions of the study area are probably the reason for the slow recovery of the most fire prone communities. Given that climate change is expected to make the conditions even drier in the region, studies like this emphasize the need to adopt measures for controlling wildfires and preventing ecosystem degradation.

scholarly journals Observations on Nephrops norvegicus (L.) and on an epizoic population of Balanus crenatus Brug

1951 ◽  
Vol 30 (2) ◽  
pp. 369-380 ◽  
Author(s):  
H. Barnes ◽  
T. B. Bagenal
Keyword(s):  
North Sea ◽  
British Isles ◽  
Nephrops Norvegicus ◽  
General Biology ◽  
Far North ◽  
North East ◽  
The North ◽  
Norway Lobster ◽  
The North Sea ◽  
The Mediterranean

The Dublin Prawn or Norway Lobster, Nephrops norvegicus (L.), is widely distributed on soft muddy bottoms, usually between 10 and 50 fathoms. It is found as far north as Iceland and the North Cape, is common in the North Sea and off the Atlantic shores of the British Isles, and extends as far south as the coast of Morocco; a variety, v. meridionalis (Zariquiey-Cenarro, 1935) is found in the Mediterranean and Adriatic (see Havinga, 1929, and Heldt & Heldt, 1931, for details of its distribution). Some aspects of the general biology of Nephrops have been dealt with by Höglund (1942) and Poulsen (1946) for Scandinavian waters, and by McIntosh (1904, 1908) and Storrow (1912)for the waters off north-east England. To a large extent all these workers relied on market catches.

Responses of vegetation to different land-use histories involving grazing and fire in the North-east Patagonian Monte, Argentina

2013 ◽  
Vol 35 (3) ◽  
pp. 273 ◽  
Author(s):  
Guadalupe Peter ◽  
Flavia Alejandra Funk ◽  
Silvia Susana Torres Robles
Keyword(s):  
Land Use ◽  
Grazing Intensity ◽  
Population Level ◽  
Bare Soil ◽  
Random Pattern ◽  
Soil Matrix ◽  
North East ◽  
The North ◽  
Functional Types ◽  
Specific Frequency

In arid and semiarid lands around the world, vegetation is distributed in patches within a bare soil matrix. Vegetation in the North-east Patagonian Monte, Argentina is a shrubland steppe, and patches are dominated by shrubs, with grasses, forbs and cryptogams under their canopy. It was hypothesised that grazing increases patchiness; and fires and wind erosion homogenise the distribution of vegetation. It was predicted that there would be: (1) greater cover, specific frequency and richness of shrubs in grazed sites; (2) greater cover, specific frequency and richness of herbs and preferred grasses in ungrazed sites; and (3) a random pattern of distribution in burnt areas. Aerial cover of all perennial species was measured at six sites with different land-use histories: heavily grazed, medium grazed, ungrazed, long exclosure from grazing followed by grazing, burnt and then ungrazed, and burnt and then grazed. Species were grouped into five functional types: shrubs, sub-shrubs, preferred grasses, non-preferred grasses and forbs. The results showed significant differences in the cover of preferred and non-preferred grasses, forbs and total cover with previous grazing but there was no evidence of shrub encroachment. Species frequency and richness decreased especially with increased grazing intensity. The pattern of spatial distribution changed from aggregated in grazed sites to random in ungrazed and burnt sites for all plant functional types. At the population level, the cover of the grass, Poa ligularis, was greatest on ungrazed sites whereas the cover of the shrub, Chuquiraga erinacea, was greatest on burnt sites. It is concluded that, after applying a heterogeneous patchwork of disturbance, such as grazing, or with fire, followed by periods of rest, the plant diversity is increased.

scholarly journals Allozymic variation in Northeast Atlantic and Mediterranean populations of Norway lobster, Nephrops norvegicus

2006 ◽  
Vol 63 (5) ◽  
pp. 875-882 ◽  
Author(s):  
Costas Stamatis ◽  
Alexander Triantafyllidis ◽  
Katerina A. Moutou ◽  
Zissis Mamuris
Keyword(s):  
Genetic Structure ◽  
Aegean Sea ◽  
Mediterranean Population ◽  
Starch Gel Electrophoresis ◽  
Nephrops Norvegicus ◽  
Genetic Studies ◽  
Mediterranean Populations ◽  
The North ◽  
Enzymatic Systems ◽  
Starch Gel

Abstract Allozyme starch gel electrophoresis was used to investigate the genetic structure of Nephrops norvegicus populations in an extended sampling scheme. Nine populations from the North Sea and Aegean Sea were sampled and analysed using ten enzymatic systems corresponding to 15 putative loci. Values of heterozygosity were similar between Atlantic and Mediterranean population samples, ranging from 0.165 to 0.187. Genetic distance estimates, FST analyses and tests for genetic differentiation revealed a heterogeneous genetic structure within the sampling area of N. norvegicus. No evidence was found of past separation of Atlantic and Mediterranean populations, agreeing with the results of previous allozymic and mitochondrial genetic studies of N. norvegicus. Data are compared with genetic studies of other marine crustaceans and fish, and the implications for management of N. norvegicus stocks are discussed.

scholarly journals ATLANTIS IN SPAIN II

2017 ◽  
Vol 43 (1) ◽  
pp. 108
Author(s):  
S.P. Papamarinopoulos
Keyword(s):  
Science Fiction ◽  
Bronze Age ◽  
Late Bronze Age ◽  
Greek Language ◽  
East Mediterranean ◽  
The Past ◽  
North East ◽  
The North ◽  
12Th Century ◽  
Archaeological Excavations

Plato, who lived in the 4th century B.C., wrote the dialogue Timaeos and Critias when he was 52 years old. In this he describes a catastrophe in Athens from an earthquake in the presence of excessive rain. He also describes several details, not visible in his century, in the Acropolis of Athens. These details are a spring and architectural details of buildings in which the warriors used to live. In Critias he mentions that the destruction of the spring was caused by an earthquake. The time of the catastrophe of Atlantis was not defined by him but it is implied that it occurred after the assault of the Atlantes in the Mediterranean. Archaeological excavations confirmed the existence of the spring which was about 25 m deep with respect to the present day walking level. Archaeologically dated ceramics, found at its bottom, denote the last function of the spring was in very early 12th century B.C. Plato describes the warriors’ settlements which were found outside of the fortification wall in the North East of the Acropolis. The philosopher, who was not a historian, describes a general catastrophe in Greece from which the Greek language survived till his century. Archaeological studies have offered a variety of tablets of Linear B writings which turn out to be the non-alphabetic type of writing of the Greeks up to the 12th century B.C. before the dark ages commence. Modern geoarchaeological and palaeoseismological studies prove that seismic storms occurred in the East Mediterranean between 1225 and 1175 B.C. The result of a fifty-year period of earthquakes was the catastrophe of many late Bronze Age palaces or settlements. For some analysts both Athens and Atlantis presented in Timaeos and Critias are imaginary entities. They maintained that the imaginary conflict between Athens and Atlantis served Plato to produce the first world’s “science fiction” and gave the Athenians an anti-imperialistic lesson through his fabricated myth. However, a part of this “science fiction”, Athens of Critias, is proved a reality of the 12th century B.C., described only by Plato and not by historians, such as Herodotus, Thucydides and others. Analysts of the past have mixed Plato’s fabricated Athens presented in his dialogue Republic with the non-fabricated Athens of his dialogue Critias. This serious error has deflected researchers from their target to interpret Plato’s text efficiently.

Reproductive biology of three caridean shrimp, Rimicaris exoculata, Chorocaris chacei and Mirocaris fortunata (Caridea: Decapoda), from hydrothermal vents

2000 ◽  
Vol 80 (3) ◽  
pp. 473-484 ◽  
Author(s):  
Eva Ramirez Llodra ◽  
Paul A. Tyler ◽  
Jonathan T.P. Copley
Keyword(s):  
Hydrothermal Vents ◽  
Early Stage ◽  
Population Level ◽  
Maximum Size ◽  
Caridean Shrimp ◽  
Rimicaris Exoculata ◽  
North East ◽  
The North ◽  
Stage Of Development ◽  
Gravid Females

The caridean shrimp Rimicaris exoculata, Chorocaris chacei and Mirocaris fortunata, together with bathymodiolid mussels, dominate the vent fauna along the Mid-Atlantic Ridge. Vent shrimp show the characteristic reproductive patterns of caridean decapods. The gonads are paired organs overlying the digestive gland under the carapace. In the ovaries, the oogonia (∼20-30 μm diameter) proliferate in the germinal epithelium at the periphery of the gonad, developing into previtellogenic oocytes. The previtellogenic oocytes grow to 70-100 μm before undergoing vitellogenesis. The maximum size for mature oocytes ranged between 200 and 500 μm depending on the species and the sample. The oocyte size–frequency data show no evidence of synchrony in oogenesis at population level for any of the species studied. Mirocaris fortunata is the only species where gravid females are commonly collected. The brood is carried on the pleopods, and the number of eggs per female ranges from 25 to 503, with a mean egg length of 0.79±0.14 mm. There is a positive correlation between fecundity and body size, characteristic of crustaceans. One ovigerous C. chacei and two R.exoculata have been studied. The former was carrying 2510 eggs and the later 988 small eggs in an early stage of development. The fecundity of M. fortunata, C. chacei and R. exoculata is significantly higher than that of species from the Acanthephyra group collected in the north-east Atlantic.

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