scholarly journals Validation of age determination using otoliths of the European anchovy (Engraulis encrasicolus L.) in the Bay of Biscay

2016 ◽  
Vol 67 (7) ◽  
pp. 951 ◽  
Author(s):  
A. Uriarte ◽  
I. Rico ◽  
B. Villamor ◽  
E. Duhamel ◽  
C. Dueñas ◽  
...  
Keyword(s):  
Age Groups ◽  
Age Determination ◽  
Annual Growth ◽  
Bay Of Biscay ◽  
Opaque Zone ◽  
Zone Formation ◽  
European Anchovy ◽  
Spawning Time ◽  
Hyaline Zone ◽  
European Anchovy Engraulis Encrasicolus

Validation of the age determination procedure using otoliths of European anchovy in the Bay of Biscay was achieved by monitoring very strong year-classes in successive spring catches and surveys, as well as the seasonal occurrence of edge types. Historical corroboration of the ageing method was obtained by cross-correlation between successive age groups by year-classes in catches and surveys (1987–2013). Summary annual growth in length is also presented. Yearly annuli consist of a hyaline zone (either single or composite) and a wide opaque zone, disrupted occasionally by some typical checks (mainly at age-0 and age-1 at peak spawning time). Age determination, given a date of capture, requires knowledge of the typical annual growth pattern of otoliths, their seasonal edge formation by ages and the most typical checks. Most opaque growth occurs in summer and is minimal (translucent) in winter. Opaque zone formation begins earlier in younger fish (in spring), and this helps distinguish age-1 from age-2+.

scholarly journals Microsatellite variability in European anchovy (Engraulis encrasicolus) calls for further investigation of its genetic structure and biogeography

2009 ◽  
Vol 66 (10) ◽  
pp. 2176-2182 ◽  
Author(s):  
Iratxe Zarraonaindia ◽  
Miguel Angel Pardo ◽  
Mikel Iriondo ◽  
Carmen Manzano ◽  
Andone Estonba
Keyword(s):  
Genetic Structure ◽  
Random Mating ◽  
Western Mediterranean ◽  
Null Alleles ◽  
Recent Common Ancestor ◽  
Bay Of Biscay ◽  
Genetic Stock ◽  
European Anchovy ◽  
Engraulis Encrasicolus ◽  
European Anchovy Engraulis Encrasicolus

Abstract Zarraonaindia, I., Pardo, M. A., Iriondo, M., Manzano, C., and Estonba, A. 2009. Microsatellite variability in European anchovy (Engraulis encrasicolus) calls for further investigation of its genetic structure and biogeography. – ICES Journal of Marine Science, 66: 2176–2182. Attention to genetic and ecological perspectives can enhance strategies for using fishery resources sustainably. A potentially important application is the use of molecular markers to assess the genetic stock structure of a harvested species. In this study, seven microsatellite markers were analysed in anchovy samples from the Bay of Biscay, the Gulf of Cádiz, and the Gulf of Lions to assess the genetic structure of anchovy (Engraulis encrasicolus) populations in the Bay of Biscay and to infer the biogeographic origin of these populations. All samples showed a deficit of heterozygotes that could be explained by non-random mating, Wahlund's effect, and especially by the presence of null alleles. Global FST and RST values, uncorrected and corrected for null alleles, were significant. There was significant genetic heterogeneity between two populations in the Bay of Biscay, suggesting that anchovy there may not be panmictic. Moreover, the results reinforce the hypothesis of a recent common ancestor shared by Bay of Biscay and western Mediterranean anchovy. These results, together with those of earlier studies, suggest merit in further investigating spatio-temporal genetic variation among anchovy populations in the Northeastern Atlantic.

scholarly journals A dynamic model of the Bay of Biscay pelagic fleet simulating fishing trip choice: the response to the closure of the European anchovy (Engraulis encrasicolus) fishery in 2005

2008 ◽  
Vol 65 (11) ◽  
pp. 2444-2453 ◽  
Author(s):  
Youen Vermard ◽  
Paul Marchal ◽  
Stéphanie Mahévas ◽  
Olivier Thébaud
Keyword(s):  
Behavioral Model ◽  
Random Utility ◽  
Bay Of Biscay ◽  
Multivariate Statistical Methods ◽  
Multivariate Statistical ◽  
Fishing Activity ◽  
Fishing Trip ◽  
European Anchovy ◽  
Engraulis Encrasicolus ◽  
European Anchovy Engraulis Encrasicolus

The scope of this paper is to describe, evaluate, and forecast fishing trip choices of the Bay of Biscay pelagic fleet using random utility modeling (RUM). First, alternative fishing trip choices of this fleet were identified using multivariate statistical methods based on species landings weighted by value and defined as distinct fishing activity or fisheries (termed métiers). A RUM was specified, which included trip components as attributes during the period 2001–2004 (a lagged percentage of the value per unit of effort of the main species caught, total value per unit of effort, and inertia in terms of changes from one métier to another). For the main métiers, the proportion of correct effort allocation is 90% during the calibration period of 2001–2004. The results from the RUM are used to parameterize a simulation model of trip choice. The model is used to predict trip choices in 2005, throughout most of which fishing was constrained by the closure of the European anchovy (Engraulis encrasicolus) fishery. Simulation results are compared with observed trip choices following the fishing ban: 80% of observed trip choices are correctly predicted by the model. The capacity of the behavioral model to predict responses to the closure is then discussed.

Formation and annual periodicity of opaque zones in sagittal otoliths of Mugil cephalus (Pisces: Mugilidae)

2003 ◽  
Vol 54 (1) ◽  
pp. 57 ◽  
Author(s):  
Kimberley A. Smith ◽  
Kerrie Deguara
Keyword(s):  
Juvenile Fish ◽  
Age Determination ◽  
Mugil Cephalus ◽  
Opaque Zone ◽  
Zone Formation ◽  
South Eastern ◽  
Eastern Australia ◽  
Annual Periodicity ◽  
Marginal Increment ◽  
South Eastern Australia

The present study used a variety of methods to validate the annual periodicity and to determine the timing of formation of opaque and translucent zones in the sagittal otoliths of sea mullet (Mugil cephalus) from south-eastern Australia. Otoliths of captive juvenile fish were sampled regularly to determine timing of formation of the first opaque zone and ‘marginal increment analysis’ was used to infer timing of formation of subsequent zones. Otoliths of tagged (oxytetracycline injected) and recaptured fish also provided direct observations about the timing and periodicity of otolith zone formation. An ‘increment’ was defined as a translucent zone followed by an opaque zone. The first opaque zone was typically completed in February–March, at an age of 22–23 months. Subsequent opaque zones were completed between November and March, but typically in December. Opaque zones were associated with periods of slow otolith growth during winter and spring. Otoliths of fish aged between 0 and 11 years were examined during the study. Otoliths were sampled from two locations on the south-eastern Australian coast, separated by 5.5° latitude. The transition between opaque and translucent zones appeared more distinct in otoliths from the higher latitude, resulting in greater precision of age estimates at this location. Precision of age estimation was also found to vary with time of year. It is recommended that sampling of otoliths for age determination of Mugil cephalus in south-eastern Australia occur from April to October. Sampling at these times would avoid months in which otolith increments are most difficult to interpret and when the stage of completion of increments is most variable.

scholarly journals Mitochondrial DNA and microsatellite genetic differentiation in the European anchovy Engraulis encrasicolus L.

2012 ◽  
Vol 69 (8) ◽  
pp. 1357-1371 ◽  
Author(s):  
Yaisel J. Borrell ◽  
Jorge A. Piñera ◽  
José A. Sánchez Prado ◽  
Gloria Blanco
Keyword(s):  
Mitochondrial Dna ◽  
Genetic Differentiation ◽  
Basque Country ◽  
Sequence Divergence ◽  
Bay Of Biscay ◽  
European Anchovy ◽  
Engraulis Encrasicolus ◽  
Polymerase Chain ◽  
The Mediterranean ◽  
European Anchovy Engraulis Encrasicolus

Abstract Borrell, Y. J., Piñera, J. A., Sanchez Prado, J. A., and Blanco, G. 2012. Mitochondrial DNA and microsatellite genetic differentiation in the European anchovy Engraulis encrasicolus L. – ICES Journal of Marine Science, 69: . The European anchovy Engraulisencrasicolus is currently one of the principal target species for commercial fisheries in Europe, and most stocks are overfished at present. In this work, specimens were sampled in the Bay of Biscay (Cantabrian, Basque Country, and French coasts) in 2009 and also in the Mediterranean (Adriatic Sea). Mitochondrial DNA (mtDNA; cytochrome b and 16S) was sequenced, and 14 nuclear microsatellites showing high and low levels of polymorphism were arranged in three multiplex polymerase chain reaction (PCR) systems and genotyped. Two main ancient mitochondrial clades were found. These clades are separated by 15 mutational steps and 1.7% sequence divergence, corresponding to a separation time of ∼0.5 million years ago. Our results using both mtDNA and microsatellites suggest the presence of at least three genetically differentiated groups: the west Cantabrian Sea, the rest of the populations in the Bay of Biscay, and the Mediterranean. Although it is known that western Iberian Atlantic populations of E. encrasicolus may be genetically different from those of the Bay of Biscay, the results suggest that the transition between these groups may be as close as a 100 km and that a recent genetic homogenization process in the eastward area of the Bay of Biscay has probably occurred.

SELECTED MORPHOMETRIC AND BIOLOGICAL CHARACTERISTICS OF IDE LEUCISCUS IDUS (LINNAEUS, 1758) IN THE LOWER IRTYSH

2017 ◽  
pp. 46-53
Author(s):  
Elizaveta L'vovna Liberman ◽  
Andrey Aleksandrovich Chemagin
Keyword(s):  
Maximum Rate ◽  
Linear Growth ◽  
Age Groups ◽  
Annual Growth ◽  
Recreational Fishing ◽  
Opisthorchis Felineus ◽  
Gonad Maturity ◽  
Study Results ◽  
Leuciscus Idus ◽  
Old Females

Ide Leuciscus idus (Linnaeus, 1758) belongs to Cyprinidae family and is used in commercial and recreational fishing. Ide is an intermediate host of Opisthorchis felineus . In the control catches (summer 2015, the Lower Irtysh, Uvatsky, Tobolsky and Vagaysky regions of Tyumenskaya Oblast’) there were observed species with lengths 11.9-38.1 cm, with a total weight 45-1085 g. Some species aged 9 years old and even older. The maximum rate of linear growth was registered in ide species younger than 3 years old, at this age annual growth made 5 cm. The annual growth of four-year-old females made 5.4 cm, males - 2.8 cm. Females aged 3+ exceeded males in body weight and length. Species at the age 1+…2+ years old added 204.6% in their mass; at the age 2+…3+ years old - 65.3%, at 3+…4+ years old - 29.4%. Gender and gonad maturity were determined in species older than 2+, but not in all species. Among females aged 2+…4+ there were found species with I and II stage of gonad maturity. Females aged 5+ were spawned-out species having VI-II stage of gonad maturity (48%); female species aged 6+ having IV stage of gonad maturity made 33.4%. Among males in the age groups of 2+ and 3+ there were registered species with I stage (38.5 and 20%, respectively) and II stage (61.5 and 80%, respectively) of maturation only. Fatness degree of studied species ranged from 0 to 5. Species aged 2+ had I stage (24% species); in the aged groups the proportion of such species decreased (5+ years old - 7.8%; 6+ years old - 12.1%; 8+ years old - 5.9%); species aged 2-7 had II stage of fatness; proportion of older species also decreased. Species with III and IV stage of fatness were found more often (III stage was observed in 100% of the fish species at the age of 1+). Proportion of species with V stage was minor, it increased with age. According to the analysis of the study results, nutritive base in the basin is found satisfactory for ide growth and development.

Age and growth pattern of the thin-lipped mullet Liza Ramada in the Eastern coast of Libya.

2016 ◽  
Vol 5 (06) ◽  
pp. 4620
Author(s):  
Manal M. Khalifa ◽  
Ramadan A. S. Ali ◽  
Abdalla N. Elawad* ◽  
Mohammad El. ElMor
Keyword(s):  
Frequency Distribution ◽  
Age Groups ◽  
Age Determination ◽  
Age And Growth ◽  
Eastern Coast ◽  
Growth Equation ◽  
Length Frequency Distribution ◽  
Length Frequency ◽  
Scale Reading ◽  
Von Bertalanffy Growth Equation

Age and growth characteristics of the thin-lipped Grey Mullet (Liza ramada) were investigated in Eastern coast of Libya. Aging was done by two methods: counting annuli on scales and by length frequency distribution, a total of 218 scales were studied for age determination, in addition of 334 fishes specimen for length frequency distribution reading. Four age groups were determined from scale reading, and five age groups from length frequency distribution methods, the parameters of the Von Bertalanffy growth equation for both sex of all individuals were estimated at 35.4 cm, 0.187 per year, -1.14 years and 2.4, for male were estimated at 35.7 cm, 0.17 per year, -1.367 and 2.3, for female were 38.6 cm, 0.156 per year, -1.383 and 2.4, for L∞, k and t0, and φ′, respectively.

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