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Keith Jones - One of the best experts on this subject based on the ideXlab platform.
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have recent mass mortalities of the sardine sardinops sagax facilitated an expansion in the distribution and abundance of the anchovy Engraulis australis in south australia
Marine Ecology Progress Series, 2001Co-Authors: Tim M. Ward, W. F. Dimmlich, F Hoedt, Lachlan J Mcleay, G Jackson, Paul J Rogers, Keith JonesAbstract:This paper examines the hypotheses (1) that Sardinops sagax and Engraulis australis are spatially segregated and do not interact directly, and (2) that recent mass mortalities of S. sagax have facilitated an expansion in the distribution and abundance of E. australis. In South Australian waters, S. sagax and E. australis both spawn during summer and autumn. Eggs and larvae of both species occur over the continental shelf, and are abundant in areas where upwelling occurs (e.g. off the Cof- fin Bay Peninsula and the western tip of Kangaroo Island) and frontal systems form (e.g. in Investi- gator Strait and the entrance of Spencer Gulf). After the mass mortality events in 1995 and 1998, eggs and larvae of S. sagax were confined mainly to these areas, and estimates of the total abundance of S. sagax eggs and larvae in South Australian waters fell by between 48 and 83% respectively. Between 1996 and 1999, densities of E. australis eggs and larvae increased in both key spawning areas and the central and eastern Great Australian Bight, and total abundance of eggs and larvae increased by over 215 and 285% respectively. These results indicate that (1) S. sagax and E. australis are not spatially segregated and may interact directly, and (2) the mass mortalities of S. sagax may have facilitated an expansion in the distribution and abundance of E. australis. Hence, fluctuations in the relative abundance of S. sagax and Engraulis spp. observed in the world's productive boundary current systems may also be possible in Australian waters.
Luis A Cubillos - One of the best experts on this subject based on the ideXlab platform.
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is the spawning frequency dependent on female size empirical evidence in sardinops sagax and Engraulis ringens off northern chile
Fisheries Research, 2007Co-Authors: Gabriel Claramunt, Rodolfo Serra, Leonardo R Castro, Luis A CubillosAbstract:In this study, we review the relationship between female size and spawning frequency using information from Sardinops sagax and Engraulis ringens, two species which are important for the economy of countries located in the Humboldt Current System. We test the hypothesis that spawning frequency is positively related to female size using information for these two species in northern Chile. The data analyzed were obtained from four different sources: (a) reproductive information obtained from the application of the Daily Egg Production Method (DEPM) in E. ringens between 1992 and 2005; (b) adult reproductive parameters for different species of the genus Engraulis; (c) spawns counts for a brood stock of E. ringens reared in captivity; (c) results from an indirect method based on a gonadosomatic calibrated index developed for S. sagax utilizing data obtained from 1974 to 1996. An analysis of the 11-year DEPM data series for E. ringens suggest that the daily spawning fraction also increases with the average weight of mature anchovy females and that such relationship may also be described using an asymptotic model. A plot of the daily spawning fraction and average female weight data obtained from results of DEPM applications for different Engraulis species from around the world also showed a positive correlation, suggesting that this relationship may be valid for many species, even those located in different habitats. An analysis of the data obtained from the E. ringens brood experiments showed that the number of eggs spawned in the tank increased monthly as female age increased, even though the number of females decreased due to natural mortality. Results in S. sagax females showed that smaller females have shorter spawning periods and a lower spawning fraction; accordingly, bigger females spawned more frequently than smaller ones. The long term estimation (1974–1996) of spawning numbers in relation to S. sagax female size was well described by a sigmoid function. © 2007 Elsevier B.V. All rights reserved.
Tim M. Ward - One of the best experts on this subject based on the ideXlab platform.
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Ontogenetic shifts in the distribution and reproductive patterns of Australian anchovy (Engraulis australis) determined by otolith microstructure analysis
Marine and Freshwater Research, 2006Co-Authors: W. F. Dimmlich, Tim M. WardAbstract:Upwelling systems can provide ideal conditions for survival and growth of larval fishes. However, these unstable environments are highly dispersive and mortalities can be high. Anchovies (Engraulis spp.) utilise a range of behavioural strategies to increase egg and larval survival. Ontogenetic shifts in distribution have been proposed for Australian anchovy (Engraulis australis), but no supporting otolith-based age studies have been published to date. The present study used otolith increment counts to age larval, juvenile and adult Australian anchovy, which spawn throughout South Australian gulf and shelf waters. Only fish up to 1 year of age occurred in the northern Spencer Gulf, where eggs and larvae in high densities are retained in a nursery area favourable to anchovies. The southern gulf area was inhabited by 1, 2 and 3 year olds. Older anchovy were found in offshore shelf waters, where upwelling occurs and larval survivorship may be high. We hypothesise that Australian anchovy move offshore with age to utilise the wide range of environments that provide suitable spawning and nursery areas for this species.
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have recent mass mortalities of the sardine sardinops sagax facilitated an expansion in the distribution and abundance of the anchovy Engraulis australis in south australia
Marine Ecology Progress Series, 2001Co-Authors: Tim M. Ward, W. F. Dimmlich, F Hoedt, Lachlan J Mcleay, G Jackson, Paul J Rogers, Keith JonesAbstract:This paper examines the hypotheses (1) that Sardinops sagax and Engraulis australis are spatially segregated and do not interact directly, and (2) that recent mass mortalities of S. sagax have facilitated an expansion in the distribution and abundance of E. australis. In South Australian waters, S. sagax and E. australis both spawn during summer and autumn. Eggs and larvae of both species occur over the continental shelf, and are abundant in areas where upwelling occurs (e.g. off the Cof- fin Bay Peninsula and the western tip of Kangaroo Island) and frontal systems form (e.g. in Investi- gator Strait and the entrance of Spencer Gulf). After the mass mortality events in 1995 and 1998, eggs and larvae of S. sagax were confined mainly to these areas, and estimates of the total abundance of S. sagax eggs and larvae in South Australian waters fell by between 48 and 83% respectively. Between 1996 and 1999, densities of E. australis eggs and larvae increased in both key spawning areas and the central and eastern Great Australian Bight, and total abundance of eggs and larvae increased by over 215 and 285% respectively. These results indicate that (1) S. sagax and E. australis are not spatially segregated and may interact directly, and (2) the mass mortalities of S. sagax may have facilitated an expansion in the distribution and abundance of E. australis. Hence, fluctuations in the relative abundance of S. sagax and Engraulis spp. observed in the world's productive boundary current systems may also be possible in Australian waters.
Gabriel Claramunt - One of the best experts on this subject based on the ideXlab platform.
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is the spawning frequency dependent on female size empirical evidence in sardinops sagax and Engraulis ringens off northern chile
Fisheries Research, 2007Co-Authors: Gabriel Claramunt, Rodolfo Serra, Leonardo R Castro, Luis A CubillosAbstract:In this study, we review the relationship between female size and spawning frequency using information from Sardinops sagax and Engraulis ringens, two species which are important for the economy of countries located in the Humboldt Current System. We test the hypothesis that spawning frequency is positively related to female size using information for these two species in northern Chile. The data analyzed were obtained from four different sources: (a) reproductive information obtained from the application of the Daily Egg Production Method (DEPM) in E. ringens between 1992 and 2005; (b) adult reproductive parameters for different species of the genus Engraulis; (c) spawns counts for a brood stock of E. ringens reared in captivity; (c) results from an indirect method based on a gonadosomatic calibrated index developed for S. sagax utilizing data obtained from 1974 to 1996. An analysis of the 11-year DEPM data series for E. ringens suggest that the daily spawning fraction also increases with the average weight of mature anchovy females and that such relationship may also be described using an asymptotic model. A plot of the daily spawning fraction and average female weight data obtained from results of DEPM applications for different Engraulis species from around the world also showed a positive correlation, suggesting that this relationship may be valid for many species, even those located in different habitats. An analysis of the data obtained from the E. ringens brood experiments showed that the number of eggs spawned in the tank increased monthly as female age increased, even though the number of females decreased due to natural mortality. Results in S. sagax females showed that smaller females have shorter spawning periods and a lower spawning fraction; accordingly, bigger females spawned more frequently than smaller ones. The long term estimation (1974–1996) of spawning numbers in relation to S. sagax female size was well described by a sigmoid function. © 2007 Elsevier B.V. All rights reserved.
Andone Estonba - One of the best experts on this subject based on the ideXlab platform.
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Development of gene-associated single nucleotide polymorphisms for Japanese anchovy Engraulis japonicus through cross-species amplification
Fisheries Science, 2018Co-Authors: Iratxe Montes, Mikel Iriondo, Carmen Manzano, Andone EstonbaAbstract:Cross-species amplification is a fast and cost-effective approach for the discovery of genetic markers in non-model species that have a phylogenetically close species with developed markers. The present study employed this method to discover new single nucleotide polymorphism (SNP) markers in the Japanese anchovy Engraulis japonicus . We selected 482 mitochondrial and nuclear SNPs described in the European anchovy Engraulis encrasicolus ; primer and probe sets developed for this species were used for genotyping 35 individuals of E. japonicus . A total of 451 SNPs (93.6%) were successfully cross-amplified, of which 176 SNPs (36.5%) were polymorphic in E. japonicus . The mean expected heterozygosity was 0.102, and no marker deviated significantly from Hardy–Weinberg proportions. Two mitochondrial SNPs were identified as a set of species diagnosing markers since, compared to four other species from the genus Engraulis , they formed a haplotype only present in E. japonicus . The new SNP set presented here constitutes the first SNP-type marker developed for E. japonicus , which is suitable for a range of applications including traceability and population genetics studies.
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Clupeiformes' Egg Envelope Proteins characterization: The case of Engraulis encrasicolus as a proxy for stock assessment through a novel molecular tool.
Molecular Phylogenetics and Evolution, 2016Co-Authors: Andrea Miccoli, Iole Leonori, Andone Estonba, Andrea De Felice, Chiara Carla Piccinetti, Oliana CarnevaliAbstract:Zona radiata proteins are essential for ensuring bactericidal resistance, oocyte nutrients uptake and functional buoyancy, sperm binding and guidance to the micropyle, and protection to the growing oocyte or embryo from the physical environment. Such glycoproteins have been characterized in terms of molecular structure, protein composition and phylogenetics in several chordate models. Nevertheless, research on teleost has not been extensive. In Clupeiformes, one of the most biologically relevant and commercially important order which accounts for over 400 species and totally contributes to more than a quarter of the world fish catch, Egg Envelope Protein (EEP) information exist only for the Clupea pallasii and Engraulis japonicus species. The European anchovy, Engraulis encrasicolus, the target of a well-consolidated fishery in the Mediterranean Sea, has been ignored until now and the interest on the Otocephala superorder has been fragmentally limited to some Cypriniformes and Gonorynchiformes, as well. The aim of the present study was to fill the ZP protein-wise gap of knowledge afflicting the understanding of the European anchovy's reproductive process and to expand the background on Clupeiformes. We cloned the five Engraulis encrasicolus' zp genes and deduced their products, determined their tissue distribution, quantified their mRNA expression throughout the reproductive cycle and provided an insight into their evolution through phylogenetic tools. Furthermore, we proposed a multivariate statistics-based method to objectively infer and/or confirm the classification of Engraulis encrasicolus' sexual maturity stages by analyzing data of zp mRNAs' relative abundance.
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microsatellite variability in european anchovy Engraulis encrasicolus calls for further investigation of its genetic structure and biogeography
Ices Journal of Marine Science, 2009Co-Authors: Iratxe Zarraonaindia, Carmen Manzano, Mikel Iriondo, Miguel Angel Pardo, Andone EstonbaAbstract: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: 000– 000. 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 microsa
