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Horse Mackerel (horse + mackerel)
Selected AbstractsGenetic differentiation of Mediterranean horse mackerel (Trachurus mediterraneus) populations as revealed by mtDNA PCR-RFLP analysisJOURNAL OF APPLIED ICHTHYOLOGY, Issue 2 2009By C. Turan Summary The genetic population structure of Mediterranean horse mackerel, Trachurus mediterraneus, from seven locations throughout the Black, Marmara, Aegean and eastern Mediterranean seas was investigated using restriction fragment length polymorphism (RFLP) analysis of the mtDNA 16S rDNA region. An approximately 2000-bp segment was screened in 280 individuals using six restriction enzymes, resulting in 10 composite haplotypes. The most common haplotype was present in 56.42% individuals; the next most frequent haplotype was present in 22.85% individuals. Average haplotype diversity within samples was moderate (0.38), and nucleotide diversity was low (0.00435). Mean nucleotide divergence for the seven sampling sites was 0.0028. Nucleotide divergence among samples was moderate, with the highest value detected between the Aegean Sea (Izmir) and the eastern Black Sea (Trabzon) populations (0.007055), and the lowest (,0.000043) between the Marmara Sea (Adalar) and the western Black Sea (Sile) populations. In Monte Carlo pairwise comparisons of haplotype frequencies, the Sinop from the middle Black Sea, Trabzon from the eastern Black Sea, and Iskenderun Bay from the north-eastern Mediterranean Sea exhibited highly significant (P < 0.001) geographical differentiation from each other and from all other populations. Mantel's test indicated that the nucleotide divergence among populations of T. mediterraneus was not significantly associated with their geographical isolation (r = ,0.2963; P > 0.05). Consequently, the mtDNA 16S rDNA region provided evidence for the existence of three distinct T. mediterraneus populations (Sinop, Trabzon and Iskenderun Bay) in the Black and north-eastern Mediterranean seas. [source] The diet of blue whiting, hake, horse mackerel and mackerel off PortugalJOURNAL OF APPLIED ICHTHYOLOGY, Issue 1 2002H. N. Cabral This paper deals with the diets of blue whiting Micromesistius poutassou (Risso 1810), hake Merluccius merluccius (L. 1758), horse mackerel Trachurus trachurus (L. 1758), and mackerel Scomber scombrus (L. 1758) off Portugal and explores variations in fish length, water depth, latitude and season. All four species feed on fish; however, hake and mackerel are the first and second most important predators, respectively, blue whiting being the most important fish prey for both species. The diets of blue whiting and horse mackerel are composed mainly of crustaceans. Diet variations according to predator fish size are more important than either latitude or depth. In the diets of blue whiting, hake and horse mackerel, prey importance increases with predator size. For blue whiting and horse mackerel, diet variations with fish length and water depth are correlated: small fish are closely associated with coastal areas where they feed on copepods and decapod larvae. Seasonality in the diet is apparent for blue whiting, hake and mackerel. For blue whiting, the decapod Pasiphaea sivado is the most important prey in summer and autumn, being replaced by the euphausid Meganyctiphanes norvegica in winter. In the diet of hake, seasonality was characterised by the major importance of Macroramphosus scolopax in autumn, whereas the diet of mackerel consisted of zooplankton in summer, fish and decapods in autumn and decapod larvae in winter. Seasonal changes in the diet of horse mackerel correspond to a higher diversity of prey in autumn compared to other seasons (although euphausids are the main prey in all seasons). Seasonality in feeding activity is not as marked for the other species as it is for horse mackerel; the percentage of empty stomachs of horse mackerel is greatest in winter, when spawning takes place at the Portuguese coast. [source] Effect of body size on the standard metabolism of horse mackerelJOURNAL OF FISH BIOLOGY, Issue 3 2000J-P. Herrmann The routine metabolic rate RR and standard metabolic rate RS were measured in horse mackerel Trachurus trachurus at 13°C over weight range of 1·4,390 g. A data extraction method rather than the more commonly used method of extrapolating the swimming speed-metabolic rate curves back to zero swimming speed was developed to measure the RS. The relation between RR and RS and weight was expressed as a linear regression with the log transformed data. The mean slope of the regression was 0·752 for RS and 0·725 for RS. [source] Hepatic coccidiosis of the blue whiting, Micromesistius poutassou (Risso), and horse mackerel, Trachurus trachurus (L.), from Galician watersJOURNAL OF FISH DISEASES, Issue 6 2001E Abollo The aetiology, epidemiology and pathology of coccidiosis in commercially-exploited populations of Micromesistius poutassou and Trachurus trachurus from Galician waters were investigated. Sporogonic stages of Goussia clupearum and G. cruciata were found in the liver. Although the descriptive statistics of Goussia infrapopulations and demographic infection values were always higher in M. poutassou than in T. trachurus, parasite distribution was highly skewed for both coccidian species. In both fish species, the number of oöcysts showed a similar cumulative effect as parasite counts increased with increasing length and weight of fish, but did not change with host sex or sexual maturity. Pathological changes in infected liver parenchyma of both species were moderate (in T. trachurus) to severe (in M. poutassou), with greatly reduced livers in the most heavily infected fish. Large areas of liver tissue were replaced with oöcysts. Host response to infection included the formation of a fibrous capsule prior to infiltration by melanin and lymphocytes. Although post-recruit individuals of both fish species apparently tolerate a severe infection, there was statistical evidence of a serious contribution by the parasite to poor body condition in M. poutassou shown by changes in the hepatosomatic and K-Fulton indices and in the length- to-weight relationship. [source] Essential elements and contaminants in tissues of commercial pelagic fish from the Eastern Mediterranean SeaJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 9 2009Beyza Ersoy Abstract BACKGROUND: It is important to determine the concentrations of essential and non-essential metals in fish for human health. The essential elements and contaminants (Pb and Cd) were determined seasonally in the muscle and liver of some pelagic fish species round herring (Etrumeus teres), chub mackerel (Scomber japonicus), golden grey mullet (Liza aurata) and Mediterranean horse mackerel (Trachurus mediterraneus) from the Iskenderun Bay, Eastern Mediterranean Sea. RESULTS: The Na, K, Ca and Mg were the most abundant elements in muscle and liver tissues. The Na, K, Ca and Mg concentrations in fish tissues were between 51.7 and 3426 mg kg,1. Muscle accumulated the lowest levels of elements. Trace element and contaminant levels in muscle were highest in spring and summer. The Cu, Zn and Cr concentrations were highest in summer. The Ni, Mn and Fe concentrations were highest in spring. The maximum Pb concentrations in the muscle and liver of fish species was 0.39 and 0.80 mg kg,1 in autumn. The maximum Cd concentration in the muscle of fish was 0.27 mg kg,1 in spring and the maximum Cd concentration in the liver was 0.78 mg kg,1 in summer. CONCLUSION: The Cr, Pb, Cd, Cu and Zn levels in muscle were found to be lower than permissible limits reported by various authorities. Estimated weekly and daily intake for Pb and Cd by consumption of fish muscle were far below the PTWI and PTDI values established by FAO/WHO. Copyright © 2009 Society of Chemical Industry [source] Effect of previous chilled storage on rancidity development in frozen horse mackerel (Trachurus trachurus)JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2002Santiago P Aubourg Abstract Rancidity development during frozen storage (,20,°C) of an underutilised medium-fat-content fish species, horse mackerel (Trachurus trachurus), was studied. Special attention was given to the effect of previous chilled storage (0, 1, 3 and 5 days) on the quality of the frozen fish. For this, chemical (free fatty acid and conjugated diene contents; peroxide value, PV; thiobarbituric acid index, TBA-i; fluorescent compound formation) and sensory (rancid odour and taste) analyses were carried out. Hydrolytic rancidity showed an increase with frozen storage time; however, no effect of previous chilling time was observed on the frozen product. Oxidative rancidity measured by chemical (PV, TBA-i and fluorescence) and sensory (odour and taste) indices increased with frozen storage time and also with previous chilling time. Satisfactory quality was maintained up to 7 months of frozen storage of horse mackerel provided that a short chilling time (not longer than 3 days) was employed. © 2002 Society of Chemical Industry [source] | ||||||||||