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Abstract Background Fish is favored by consumers, while amino acids and fatty acids are the main nutrients of muscle. At present, it has been found that the gut microbial community may be involved in the regulation of host material anabolism. Juvenile and adult bighead carp (A. nobilis) from Chagan lake and Xinlicheng reservoir were selected, and divided into four groups to compare the differences of gut microbial communities, free amino acid and fatty acids in muscle. Results The results showed that fish in different lakes or ages contained specific microbiota, the gut microbial structure was similar, but the microbial content was significantly different. Gut microbial abundance of juvenile fish in Chagan lake was significantly higher than that of other groups. Phylum level analysis Proteobacteria was the dominant gut bacteria of fish in both adult and juvenile fish from two separate lakes. Actinobacteria was another dominant bacterial phylum in juvenile fish in both lakes. Contents of free amino acids and fatty acids in muscle were detected, and the relationships between them and gut microbial communities were analyzed. Bighead carp grew from juvenile to adult, Actinobacteria abundance decreased (P

Background: Fish is favored by consumers, while amino acids and fatty acids are the main nutrients of muscle. At present, it has been found that the gut microbial community may be involved in the regulation of host material anabolism. Juvenile and adult bighead carp (A. nobilis) from Chagan lake and Xinlicheng reservoir were selected, and divided into four groups to compare the differences of gut microbial communities, free amino acid and fatty acids in muscle. Results: The results showed that fish in different lakes or ages contained specific microbiota, the gut microbial structure was similar, but the microbial content was significantly different. Gut microbial abundance of juvenile fish in Chagan lake was significantly higher than that of other groups. Phylum level analysis Proteobacteria was the dominant gut bacteria of fish in both adult and juvenile fish from two separate lakes. Actinobacteria was another dominant bacterial phylum in juvenile fish in both lakes. Contents of free amino acids and fatty acids in muscle were detected, and the relationships between them and gut microbial communities were analyzed. Bighead carp grew from juvenile to adult, Actinobacteria abundance decreased (P < 0.05) and Proteobacteria increased (P < 0.05). Proteobacteria was positively correlated with the contents of Thr, Lys, Pro, Asp, Gly and Glu, Actinobacteria was negatively correlated with Met and His. Meanwhile, EPA and DHA were positively correlated with Proteobacteria, EPA and DHA were not significantly associated with Actinobacteria. Conclusion: It was speculated that the contents of free amino acids and fatty acids in muscle might be affected by the difference of gut microbiota, thus affecting the taste and nutritional quality. [ABSTRACT FROM AUTHOR]

Purpose. Studying the peculiarities of the genetic structure of different age groups of silver and bighead carps from fish farm Limanske with the use of genetic-biochemical markers. Methodology. The methods of vertical polyacrylamide and horizontal starch electrophoresis with our own modifications have been used for the study. Sampling of the biological material and histochemical staining of gel plates were carried out using the generally accepted methods. Statistical analysis of the obtained data were performed in "Biosys-I". Findings. We analyzed the genetic structure of age-1, age-1+ and age-2 of silver and bighead carps with the use of genetic-biochemical markers - Рralb, EST, MDH, МЕ, СА. We demonstrated the peculiarities of allele frequencies and genotypic composition of protein system loci. A high level of heterozygosity in the examined was detected loci for age-1 silver carp – 66.7-88.9% and age-1 bighead carp – 65.4-77.8%. A significantly higher level of the observed average heterozygosity compared to the expected heterozygosity of age-1 as silver carp (Ho = 75.9%, He = 49,6%), and bighead carp (Ho = 73,6%, He = 47,9%) was observed. This fact indicated on the necessity for performing a stabilization of their genetic structure. The calculated Wright's F index in different age groups showed a predominance of the observed level of the average heterozygosity over the expected one for 22.7–53% in silver carp and 24.5-53.7% in bighead carp. A stabilization of the genetic structure in age-2 silver carp (Ho = 57.8%; He = 47.1%) by the heterogeneity level was observed. Originality. For the first time we analyzed the genetic structure and the level of heterogeneity of the breeding groups of age-1, age-1+, age-2 silver and bighead carps from fish farm Limanske with the use of genetic-biochemical markers. Practical value. The results of the study can be used in selection and breeding works aimed at creating the breeding stocks of silver and bighead carps to control the level of interspecies genetic variability. The obtained experimental data of the genetic structure analysis of silver and bighead carps of different age groups will be used for the monitoring of the genetic structure changes during their adaptation to new environmental conditions.

Growth performance of bighead carp (Aristichthys nobilis) in monoculture system with and withoutsupplementary feeding indicated that supplementary feeding played an important role in better growth ofbighead carp. The average initial weight of bighead carp at the time of stocking was 11.40 ± 3.25g and finalweight of 902.00 ± 4.63g was recorded after 12 months of experiment using organic (cow dung) andinorganic (urea and single super phosphate) fertilizers. The average initial weight at the time of stocking ofbighead carp was 10.3 ± 1.32g and average final weight was 1170 ± 4.85g at the end of experiment usingfertilizers and supplementary feed with 20% crude protein. Significantly higher (P

Aims: A study was conducted to compare the intestinal microbial compositions of two fish species with similar feeding strategy; paddlefish (Polyodon spathala) and bighead carp (Aristichthys nobilis) reared in the same pond. Methods and Results: Age-0 paddlefish and bighead carp with mean average body lengths of 43·39 ± 2·78 and 19·33 ± 3·68 cm, respectively, were reared with natural prey items in the same pond (20 m2). After 30 days of rearing, the intestinal microbiota of the two fish species was assessed by pyrosequencing of 16S rRNA genes. Interestingly, deviations were observed in the microbial communities of the two fish species according to the alpha- and beta-diversity measurements and detrended correspondence analysis (DCA). Shannon diversity (P = 0-015) and Pielou.evenness (P = 0-035) revealed significant lower diversity of the intestinal microbiota of paddlefish. Moreover, different core intestinal microbiota was noticed in the two fish species. Proteobacteria (57-3%), Firmicutes (11-9%), Fusobacteria (8-9%), Planctomycetes (7-3%), Actinobacteria (6-0%) and Verrucomicrobia (3-2%) were detected in bighead carp, while the dominant phyla in paddlefish intestines were Bacteroidetes (37-0%), Fusobacteria (35-1%), Firmicutes (14-8%) and Proteobacteria (12-6%). Conclusions: Our results revealed that the intestinal microbiota differed between paddlefish and bighead carp reared in the same pond when fed similar nature food. The potential host factors, such as the genetic background, gut histology and physiology are assumed to be involved in the intestinal bacterial compositions. Significance and Impact of the Study: Considering the similar feeding strategy of paddlefish and bighead carp, this study presents basic knowledge for evaluation of the importance of host factors (genetic background and gut anatomy) on intestinal microbial composition. [ABSTRACT FROM AUTHOR]

Gene-centromere mapping using half-tetrad analysis is a powerful tool for understanding chromosomal behaviour and determining the position of centromeres in relation to genes or markers in fish. In this study, eight gynogenetic diploid families induced by inhibiting of the second meiotic division were genotyped at 66 microsatellite loci for microsatellite-centromere ( M-C) mapping in bighead carp ( Aristichthys nobilis). The absence of paternal alleles verified the success of gynogenetic development in all gynogenetic families. All loci were consistent with Mendelian segregation in control families. The estimated recombination frequency ( y) ranged from 0.057 to 0.875 with an average of 0.477 ± 0.222. Seventeen loci (25.76%) showed high M-C recombination frequencies of over 0.667. M-C distances ranged from 2.85 to 43.75 cM under the assumption of complete interference. Thus, these loci are distributed from the centromeres to the telomeres of their respective chromosomes, while mainly in the intermediate region. Information on centromere mapping could serve as a starting point to consolidate the genetic linkage groups in bighead carp. [ABSTRACT FROM AUTHOR]

The contents of the proximate composition of amino acids and fatty acids in the muscle of juvenile bighead carp (Aristichthys nobilis) and paddlefish (Polyodon spathula) that were fed with live feed for 60 days were assessed in this investigation. The moisture, crude protein, and crude ash contents of bighead carp muscle were slightly higher than those of paddlefish (P > 0.05). The crude fat content of paddlefish muscle was significantly higher than that of bighead carp (P < 0.01). Seventeen amino acids were detected in the muscle of both bighead carp and paddlefish. The total concentrations of amino acids (TAAs), essential amino acids (EAAs), and delicious amino acids (DAAs) in the muscle of bighead carp were higher than in those of paddlefish. Fifteen fatty acids were detected in both bighead carp and paddlefish muscles, including 5 saturated fatty acids (SFAs), 4 monounsaturated fatty acids (MUFAs), and 6 polyunsaturated fatty acids (PUFAs). The concentrations of muscle ∑ SFAs, ∑ MUFAs, ∑ PUFAs, ∑ UFAs, ∑ SFAs/∑ UFAs, ∑ n-6 PUFAs, ∑ n-3 PUFAs, eicosapentaenoic acid (EPA), EPA + docosahexenoic acid (DHA), essential fatty acids (EFAs), and half-essential fatty acids (HEFAs) in bighead carp were signifcantly lower than those in paddlefish (P < 0.01). In addition, bighead carp possessed significantly lower muscle ∑ n-6 PUFAs/∑ n-3 PUFAs content than paddlefish did (P < 0.05). Muscle DHA content of bighead carp was higher than that of paddlefish (P < 0.05). [ABSTRACT FROM AUTHOR]

Abstract: Lectins play an important role in many biological systems and are used increasingly in human disease therapy. To improve our understanding of fish lectins we purified and characterized a fucose-binding lectin from the gill of bighead carp (Aristichthys nobilis). The purification procedure consisted of extracting soluble proteins in 25mM Tris–HCl buffer (pH 8.5), separation on a DEAE-Sepharose FF ion exchange column, followed by gel filtration chromatography on Sephacryl S-200 HR and Superdex 200 10/300 GL columns. The purified lectin, designated GANL, had a single protein band with an apparent molecular mass of 37kDa when subject to SDS-PAGE under reducing conditions. GANL is a homomultimeric glycoprotein with a native molecular mass of 220kDa and a carbohydrate content of ∼13.4%. The purified lectin only agglutinated rabbit native erythrocytes, and did not require Ca2+. Its activity was not inhibited by any of the mono- or disaccharides or glycoproteins tested, except for fucose. GANL contains a high proportion of Asp, Glu, Leu, Val, and Lys. The first 10 residues of the N-terminal region were determined as AGEQGGQCSA. The anti-microbial activity was assessed by measuring agglutination and inhibition of pathogen growth. Our results suggest that GANL agglutinates and inhibits the growth of Vibrio harveyi but has no antifungal activity. [Copyright &y& Elsevier]

Bighead carp (Aristichthys nobilis Oshima) fry of various ages (11, 18, and 35 days post-hatch) were exposed to the low salinities encountered during the annual intrusion of seawater in Laguna Lake, Philippines. Practical indices of salinity tolerance assessed the effect of a 96 h direct exposure to low salinities (0–16‰). Mean (MST) and median survival times (MST50) of fry decreased as salinity of rearing medium increased. Younger fry were less able to tolerate exposure to these salinities than their older cohorts. Median lethal salinity after 96 h (MLS) revealed higher tolerance among 35–day old fry (7.6‰) than 11 (2.3‰) and 18–day old fry (6.0‰), demonstrating that survival in saline water depends on their age at initial exposure to low salinities. Mean body weight of 18–day old fry reared in 0 and 2‰ for 3 and 4 weeks was higher than for those reared in 4 and 6‰ for the same period. Growth over these periods was inversely related with the range of salinities tested. These results demonstrate that, despite their known stenohalinity, bighead carp fry possess some degree of osmoregulatory capability, allowing them to survive and grow in lakes subjected periodically to saltwater inflow. [ABSTRACT FROM AUTHOR]

• Ultrasonication was applied to the thawing process of bighead carp. • Differences of thawing methods on quality of slow/fast frozen bighead carp were compared. • Shorten thawing time by ultrasound was observed. • Fast frozen samples lost massive water after water immersion or ultrasonic thawing. • Freezing-thawing cycles did not affect the primary protein structure of fish samples. Effects of ultrasound-assisted thawing (UAT), air thawing (AT) and water immersion thawing (WIT) on the quality of slow freezing (SF)/fast freezing (FF) bighead carp (Aristichthys nobilis) fillets were investigated. The thawing time of AT, WIT and UAT were 138, 30 and 12 min, respectively, indicating that UAT improved the thawing efficiency. UAT maintained the color and pH, and inhibited the lipid oxidation of SF/FF samples. For SF samples, thawing methods did not affect water retention and muscle structure. However, massive water loss and muscle destruction were observed in FF-WIT and FF-UAT samples. The AT did not produce any structural muscle damage; instead, it maintained the water retention in FF samples and prevented the FF fish fillets from massive water loss. No significant difference in the primary protein structure was observed among all samples. UAT can be an alternative strategy to the traditional thawing of SF fish fillets. [ABSTRACT FROM AUTHOR]