Scomber Research Articles

Rapid and specific detection of mackerels of the genus Scomber using loop-mediated isothermal amplification (LAMP)

Rapid and specific detection of mackerels of the genus Scomber using loop-mediated isothermal amplification (LAMP)

Comprehensive and species-specific detection of mackerels of the genus Scomber in processed foods using SYBR Green-based real-time PCR

Comprehensive and species-specific detection of mackerels of the genus Scomber in processed foods using SYBR Green-based real-time PCR

Vertical migration patterns linked to body and environmental temperatures in chub mackerel

Fishes in the genus Scomber are currently one of the most abundant, economically important, and widely distributed fishes in the North Pacific and North Atlantic Oceans. This study recorded the depth, peritoneal and environmental temperature of the chub mackerel Scomber japonicus using an electronic tag. The 176 tagged mackerel were released from Tsushima Strait, Japan. A total of 1,075 days of data from November to August were obtained from seven individuals. Mackerel extensively used the epipelagic zone, and ranges of depth and environmental temperature during the overall recording period were 0.5–213 m and 3.4–29.1 °C, respectively. The mean depth during the day was deeper than that observed during the night in the foraging season. This vertical distribution pattern of the mackerel may overlap with that of prey organisms. We also observed a unique short-term vertical migration of mackerel during the foraging season. When the mackerel repeated the short-term vertical migrations, ranges of peritoneal temperature (13.9–15.0 °C) were narrower than environmental temperature (7.9–16.5 °C). This behavior allowed the mackerel to use physiologically unsuitable thermal layers, while avoiding overcooling of body temperature. However, these vertical migration patterns broke down in the spawning season. Behavioral decisions of diel vertical migration in chub mackerel may be affected by body condition of individual fish such as maturation states. Quantifying vertical migrations of Scomber species occupying intermediate trophic levels is important when considering conservation strategies of more than simply fisheries stock but also that of marine ecosystems.

One is not enough: Monitoring microplastic ingestion by fish needs a multispecies approach.

The development of monitoring programs based on bioindicators is crucial for assessing the impact of microplastic ingestion on marine organisms. This study presents results from an Italian pilot action aimed at investigating the suitability of a monitoring strategy based on a multispecies approach. The benthic-feeder Mullus barbatus, the demersal species Merluccius merluccius, and the pelagic-feeder species of the genus Scomber were used to assess the environmental contamination by microplastics in three different marine areas, namely Ancona (Adriatic Sea), Anzio (Tyrrhenian Sea), and Oristano (Western Sardinia). Microplastic ingestion frequencies were higher in samples from Anzio (26.7%) and Ancona (25.0%) than Oristano (14.4%), suggesting a relationship between microplastic bioavailability and the proximity to urban settlements and river flows. Furthermore, microplastic ingestion was affected by the feeding habits of the examined species. The detected differences reinforce the hypothesis that a multispecies approach is needed to evaluate microplastic ingestion by marine animals.

A genome assembly of the Atlantic chub mackerel (Scomber colias): avaluable teleost fishing resource.

The Atlantic chub mackerel, Scomber colias (Gmelin, 1789), is a medium-sized pelagic fish with substantial importance in the fisheries of the Atlantic Ocean and the Mediterranean Sea. Over the past decade, this species has gained special relevance, being one of the main targets of pelagic fisheries in the NE Atlantic. Here, we sequenced and annotated the first high-quality draft genome assembly of S.colias, produced with PacBio HiFi long reads and Illumina paired-end short reads. The estimated genome size is 814 Mbp, distributed into 2,028 scaffolds and 2,093 contigs with an N50 length of 4.19 and 3.34 Mbp, respectively. We annotated 27,675 protein-coding genes and the BUSCO analyses indicated high completeness, with 97.3% of the single-copy orthologs in the Actinopterygii library profile. The present genome assembly represents a valuable resource to address the biology and management of this relevant fishery. Finally, this genome assembly ranks fourth in high-quality genome assemblies within the order Scombriformes and first in the genus Scomber.

Diet Composition of the Chub Mackerel Scomber japonicus in the Coastal Waters of the South Sea of Korea

Diet Composition of the Chub Mackerel Scomber japonicus in the Coastal Waters of the South Sea of Korea

Prevalence of microplastics and anthropogenic debris within a deep-sea food web

Microplastic particles (<5 mm) are ubiquitous throughout global marine ecosystems, including the deep sea. Ingestion of microplastics and other anthropogenic microparticles is reported in diverse marine taxa across trophic levels. Trophic transfer, or the movement of microplastics across trophic levels, is reported in laboratory studies but not yet widely measured in marine food webs. The Monterey Bay submarine canyon ecosystem contains a well-studied, known deep-sea food web in which to examine the trophic fate of microplastics. We measured microplastic abundance across 17 genera spanning approximately 5 trophic levels and a diversity of feeding behaviors. Samples were collected using remotely operated vehicles and oblique midwater trawls, and gut contents of all individuals examined (n = 157) were analyzed for microplastic abundance and other anthropogenic particles greater than 100 µm using stereo microscopy. Microparticles were analyzed with Raman spectroscopy to confirm material type. Anthropogenic particles were found in all genera examined, across crustacean, fish, mollusk, and gelatinous organisms, in amounts ranging from 0 to 24 particles per individual. There was no significant relationship between microplastic amount and fish trophic level, suggesting that the trophic transfer of microparticles is not occurring. Body size was positively correlated with microplastic abundance across all taxa. The fish genus Scomber sp. drove this relationship, suggesting higher microparticle abundance in mobile individuals with broad horizontal distributions. Future work should examine physiological pathways for microplastic transport within organisms (e.g. excretion, accumulation on gills, internal translocation of particles) and between organisms within shared habitats to more fully understand the fate of microplastics within aquatic food webs.

Didymozoids in Muscle of Atlantic Chub Mackerel (Scomber colias).

Digenean trematodes of the family Didymozoidae are tissue parasites that are particularly common in scombrid fish. These parasites can reduce the commercial value of fish, especially the ones occurring in the muscle. In the present study and for the first time, we report the occurrence of didymozoids in muscle tissue of Atlantic chub mackerel (Scomber colias) collected in northeast Atlantic (Portuguese coast). The entire musculature of 64 Scomber colias was removed and examined macroscopically and under a stereomicroscope to search for parasites. The prevalence (3.1%) and abundance (0.03) of infection detected were quite low, but the parasites cause muscle softening decreasing the quality of the infected fish. If the infection levels increase, this may constitute a cause of concern for the fisheries and canning industry. Didymozoids identified in this study are closely related to muscle parasites detected in other fish species of the genus Scomber, most probably the same species. Phylogenetic analysis also corroborates the hypothesis that muscle-parasitizing didymozoids are distinct from the ones parasitizing other fish organs.

Assessment of heavy metal content in imported and local fish and crustacean species obtained within Lagos Metropolis

Fishes are known for their abilities to concentrate heavy metals in their muscles and since they play important role in human nutrition, they need to be carefully screened to ensure that unnecessary high level of some toxic trace metals are not being transfer to man through their consumption. The study was to evaluate heavy metals (chromium, lead, iron and cadmium) in imported and local species of shrimps, crabs and fish using Atomic Absorption Spectroscopy. The selected imported species were horse mackerelkote fish (Trachurus trachurus), mackerel - titus (Scomber scrombus), croaker (Pseudotolithus typus), smooth swim crab (Portunus validus) and pink shrimp (Farfantepenaeus notialis) while the local species used were; Sole fish (Cynoglossus senegalensis), Tilapia (Oreochromis niloticus), brackish water catfish (Chrysichthys nigrodigitatus), freshwater catfish (Clarias gariepinus), lagoon crab (Callinectes amnicola) and freshwater prawn (Macrobrachium macrobrachion). It was observed that there was no significant difference in the metals (Cd, Pb and Cr) between the imported and local fish species and between imported and local crustacean species. However, these metals concentrated more in the local fish species, O. niloticus (1.846 ± 1.00 mg/100g). The mean heavy metals concentration occurred in the following decreasing order: Fe > Cd > Pb > Cr for all the samples. The mean concentrations of the analyzed heavy metals in the samples were below the maximum permissible limits as recommended by the International Atomic Energy Agency (IAEA), United Nations Environment Program (UNEP) and Federal Environmental Protection Agency (FEPA) for heavy metals in fish.Keywords: Fish, Shrimp, Crab, Heavy metal, Chromium, Lead, Iron

Food Component Characteristics of Bone-softened Mackerel Scomber japonicus Product

Food Component Characteristics of Bone-softened Mackerel Scomber japonicus Product

Taxonomic review of Argentine mackerel Scomber japonicus (Houttuyn, 1782) by phylogenetic analysis.

Taxonomically, Argentine mackerels were first considered as Scomber japonicus marplatensis and later as Scomber japonicus Houttuyn 1782, although, in the last years, different studies have suggested that South Atlantic mackerel species belongs to Scomber colias Gmelin 1789. These latter results, incorporated in the main fish databases (FishBase and Catalog of Fishes), promoted a phylogenetic study using cytochrome c oxidase I (COI) gene sequences taken from the Barcode of Life (FISH-BOL) database. Thus, 76 sequences of S. japonicus, S. colias, S. australasicus and S. scombrus from different regions were used; including 3 from Sarda sarda as outgroup. Among S. japonicus selected sequences are those corresponding to the Argentine mackerels collected in 2007. Phylogenetic trees were obtained by neighbor joining and maximum likelihood methods and a network of haplotypes was reconstructed to analyze the relationship between species. The results showed the clear differentiation of S. australasicus, S. scombrus and S. japonicus from the Pacific while S. japonicus from Argentina was included in the S. colias group, with genetic differences corresponding to conspecific populations (0.1%). Four of the five Argentine specimens shared the same haplotype with S. colias, and none were shared with S. japonicus from the Pacific. These results suggest that the current specific name of Argentine mackerel S. japonicus should be changed to S. colias, in agreement with several genetic studies carried out with species of the genus Scomber.

Effects of Cooking Methods on Proximate and Metal Contents of Some Common Fish Species

Cooking methods influence nutritive values of food. Proximate and metal contents of roasted and deep-fried Scomber scombrus (Titus), Clarias gariepinus (Cat fish) and Sardinops pilchardus (Sardine) were determined using standard methods. Protein contents of the fried fish were lower compared to the roasted fish. Scomber scombrus had the highest fat content (22.51%) and the least level (17.75%) in Clarias gariepinus, irrespective of the type of cooking method used. The highest (740.65 mg/Kg) and the lowest (6.11 mg/Kg) levels of calcium were both recorded in roasted Clarias gariepinus. Mineral elements varied in the order of Ca > Mg > Fe > Zn > Cu > Mn for the processed fish. The impacts of the different cooking methods on proximate and mineral contents of the fish were significantly different (P ≤ 0.05), except for carbohydrate, copper and manganese. Roasting method provided the best results when both nutrients and preservation are the priorities.

Scomber indicus, a new species of mackerel (Scombridae: Scombrini) from Eastern Arabian Sea

Scomber indicus, a new species of mackerel is described based on the specimens collected from the eastern Arabian Sea. The species is differentiated from its nearest congener Scomber australasicus, in having 29-32 gill rakers on lower limb of first gill arch, posteriormost part of hypohyal blunt, with presence of a pit between the hypohyal and the ceratohyal and also in having a posteriorly directed haemal spine which is deeply curved in the basal region. Genetic differentiation and divergence between the newly described species and the 4 valid species of the genus Scomber viz., S. scombrus, S. japonicus, S. australasicus and S. colias were compared using cytochrome c oxidase 1 and cytochrome b gene sequences. The new species was found closest to S. colias followed by S. japonicus with Kimura 2 parameter (K2P) values of 1.4 and 1.8% respectively. In the phylogenetic tree, sequences of Scomber indicus sp. nov. formed a distinct well separated clade with significant bootstrap values as compared to the sequences of S. scombrus, S. japonicus, S. australasicus and S. colias indicating their distinctiveness and separate species status.

冷凍前の鮮度がゴマサバ冷凍品のドリップと氷結晶生成に及ぼす影響について

ゴマサバにおいて，冷凍前の鮮度が氷結晶の生成に及ぼす影響を調べた。漁獲後の冷蔵時間が異なるものを−20°C で冷凍すると，冷蔵時間の短いものは氷結晶が小さく筋繊維内に多く生成されたが，冷蔵時間の長いものは氷結晶が大きく結合組織部分に生成された。漁獲後の冷蔵時間が長いものは，ドリップ量が多く，ドリップ中の遊離アミノ酸量が多くなる傾向にあった。以上の結果から，ゴマサバでは冷凍前の鮮度低下に伴いタンパク質などが分解を受け，結合組織が変化し，氷結晶の生成に影響を及ぼすことが推測された。

Fossil mackerel (Actinopterygii: Scombridae: Scomber) from the Neogene of South-Western Sakhalin, Russia

The caudal part of a skeleton of mackerel Scomber sp. in the deposits of the Kurasi Formation of Middle-Upper Miocene of south-western Sakhalin Island is reported. It is the first finding of a fossil representative of the suborder Scombroidei in the Far East of Russia. The genus Scomber comprises 4 recent and about 10 fossil species from Oligocene to Pliocene of Europe, North America (California) and East Asia (Japan). Preservation of the material studied was not good enough to allow a detailed comparison of the Sakhalin mackerel with known both recent and extinct species of the genus.

Analysis of applicability of Peleg model to the cooking-infusion of mackerel (Scomber japonicus) slices

Fil: Checmarev, Gerardo. Universidad Nacional de Mar del Plata. Facultad de Ingenieria. Departamento de Ingenieria Quimica. Grupo de Investigacion en Preservacion y Calidad de Alimentos; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Mar del Plata; Argentina

POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) IN SEAFOODS CAUGHT IN CORIGLIANO CALABRO GULF (CS,ITALY)

Polycyclic aromatic hydrocarbons (PAHs) were determined by high performance liquid chromatography (HPLC) with fluorescence detection in seafoods (Merluccius merluccius, Arnoglossus laterna, Scomber japonicus, Penaeus kerathurus, Eledone cirrhosa) collected along coasts of Corigliano Calabro gulf (Calabria Region - Italy). The results showed that Bap levels exceeded the limit fixed by EU Regulation 1881/2006 in only four samples of Merluccius merluccius, Arnoglossus laterna and Scomber japonicus particularly. PAH concentrations detected in samples caught in winter were higher than those found in summer.

Diversity of the edible fishes of the Lagos Lagoon, Nigeria and the public health concerns based on their Lead (Pb) content

In this study, a total of eighteen fish species were recorded in the Lagos Lagoon, Nigeria during a one year survey. Among the animals species recorded, the following, Galeoidesdecadactylus, Dentex gibbosus, Elops lacerta, Scomber japonicus, Ethmalosa fimbriata, Lutjanus agennes, Caranx senegallus, Callinectes amnicola, Paeneus notialis and Mytilus edulis were considered to be abundant in the Lagos lagoon based on the frequency of occurrence in fishermen catches. The analysis of the lead content in muscles of the edible fisheries revealed that the animals accumulated measurable quantity of lead in the edible parts. The level of lead detected in most (12 out of 18 species) of the fisheries species were found to be lower than the daily allowable concentration of 2.0 µg/g standard recommended by the World Health Organisation (WHO). Fishes species with high level of lead in their edible parts include Senegal jack, C. senegallus (2.188 µg/g), Bobo croaker, Pseudotolithus elongatus (2.024 µg/g), Cassava croaker, Pseudotolithus senegalensis (3.157 µg/g), crayfish, Penaeus notialis (25.46µg/g), edible mussel, Mytilus edulis (17.69 µg/g) and crab,Callinectes amnicola (10.19 µg/g). The mean levels of lead in Mytilus edulis, Penaeus notialis, and Callinectes amnicola collected from the Lagos lagoon were about 8 to 24 times higher than the WHO daily allowable standards for lead in sea foods and are therefore unsafe for human consumption. The need for regular monitoring of the levels of metals and other contaminants in edible fisheries resources and collaboration between environmental, health and food agencies to avert human tragedies due to lead accumulation are discussed. Key words: Bioaccumulation, lead, industrial pollution, aquatic ecosystem, biomonitoring.

漁獲ストレスを受けたゴマサバの短期蓄養によるストレス回復

蓄養サバ流通品を調査した結果，氷蔵 9 h 後でも筋肉の ATP 濃度は高く維持され高品質を示した。そこで，まき網で漁獲されたゴマサバを短期蓄養した場合の品質に与える影響を検討するため，漁獲ストレスの影響とその回復について検証した。生け簀で 20 分間の強制運動をさせた後，72 h 蓄養し，体内代謝変化を測定した。強制運動により血漿コルチゾル濃度や筋肉乳酸濃度は上昇するが，蓄養により低下し，肝臓グリコーゲン濃度も回復した。一方，筋肉 ATP 濃度は，強制運動直後でも高い値を示し，蓄養による変化は認められなかった。

Expression Profiles of Gthβ Subunit mRNAs during Seasonal and Spawning Cycles in Female Chub Mackerel Scomber japonicus and in Vitro Steroid Potency of Purified Gths in Vitellogenic Oocytes

Expression Profiles of Gthβ Subunit mRNAs during Seasonal and Spawning Cycles in Female Chub Mackerel Scomber japonicus and in Vitro Steroid Potency of Purified Gths in Vitellogenic Oocytes