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The effects of various combinations of storage and heating conditions on the texture and taste-active compounds in red seabream Pagrus major were investigated. The hardness increased more with high-temperature/short-time heating and storage for 14 days. Hierarchical cluster analysis based on taste-active compounds was affected by storage and heating conditions, particularly by storage. The equivalent umami concentration was higher after 14 days of storage, although the differences were not always significant. Our results suggest that red seabream heated after a short storage period, such as 14 days, may improve the levels of taste-active compounds and umami concentration in heated fish. [ABSTRACT FROM AUTHOR]

The feeding habits and habitats of fish influence the morphology of the oral cavity. This study used gross anatomy, light microscopy, and scanning electron microscopy, in addition to morphometric analysis, to investigate the anatomical characteristics of the oral cavity roof in Pagrus pagrus and Boops boops, which have different dietary habits. The oral cavity roof appeared U‐shaped and divided into the palate and upper pharyngeal regions. The upper lip of P. pagrus was broad, while B. boops' upper lip was small and thin. Both species had a stratified squamous epithelium with an irregular shape and a folded surface. P. pagrus had a horseshoe‐shaped upper velum with a high middle part, and its surface resembled sea waves with obvious mucous‐secreting openings with cilia and many folds and grooves between them. B. boops's upper velum was thin and appeared as a triangle pouch with a pointed cranial apex. The palate in both species was narrow in the front and increased in width backward until it ended. The upper pharyngeal teeth in P. pagrus appeared as two patches, separated by a median longitudinal ridge and an anterior V‐shape separator. Meanwhile, in B. boops, they appeared as a ball patch on both sides and a separator ridge in the middle. Because P. pagrus fed on harder structures than B. boops, their feeding habits were reflected in the structure of the oral cavity roof. P. pagrus, a carnivorous species, had several rows of sharp upper jaw and upper pharyngeal teeth, thick spinous tubercles on oblique transverse ridges, and massive mucous glands. On the other hand, B. boops, an omnivorous species, had only one row of upper jaw teeth, a few upper pharyngeal teeth scattered on two oval patches, and thin filaments on the oblique transverse ridges. [ABSTRACT FROM AUTHOR]

TGF-β1/Smads is a classic signaling pathway, which plays important roles in the development process of organisms. Black porgy Acanthopagrus schlegelii and red porgy Pagrus major are valuable economic fishes, and their hybrid offspring show excellent heterosis traits. Yet the molecular regulation mechanism of the heterosis traits is less clear. Here, we explored the TGF-β1/Smads pathway's molecular genetic information for heterosis in A. schlegelii ♂ × P. major ♀ (AP) and A. schlegelii ♀ × P. major ♂ (PA) in terms of growth and development. The mRNA expression levels of TGF-β1, TβR-I, TβR-II, and Smad2 genes in different developmental stages of A. schlegelii were detected. Furthermore, the expression levels of TGF-β1, TβR-I, TβR-II, and Smad2 genes in different tissues of adult (mRNA level) and larva (mRNA and protein level) of A. schlegelii, P. major, and their hybrids were determined by both real-time quantitative PCR and Western blot techniques. The results indicated the ubiquitous expression of these genes in all developmental stages of A. schlegelii and in all tested tissues of A. schlegelii, P. major, and its hybrids. Among them, the mRNA of TGF-β1, TβR-I, and TβR-II genes is highly expressed in the liver, gill, kidney, and muscle of black porgy, red porgy, and their hybrid offspring. There are significant changes in gene and protein expression levels in hybrid offspring, which indirectly reflect hybrid advantage. In addition, there was no correlation between protein and mRNA expression levels of Smad2 protein. The results provide novel data for the differential expression of growth and development genes between the reciprocal hybridization generation of black porgy and red porgy and its parents, which is conducive to further explaining the molecular regulation mechanism of heterosis in the growth and development of hybrid porgy. [ABSTRACT FROM AUTHOR]

A formerly unexploited stock of red porgy that was intensely fished along southern Brazil in the 1970s collapsed in less than a decade. Subsequently, population dynamics or stock status has not been reported, so we updated growth parameters by analysis of otolith annual‐increments and micro‐increments. Growth did not change after the stock collapsed, which suggested no density‐dependent effect. Given the lack of growth changes and data‐limitation, we used an age‐structured assessment model set until 1984 to forecast relative spawning biomass and assess recovery possibilities. Projections showed that a 19 years moratorium would have been necessary for the stock to rebuild. The model suggested an annual catch of at least 170 t in the post‐collapse period because the stock did not recover, and a small‐scale hand‐line fishery with unreported landings continued fishing. Our results reinforced the need for more curated and up‐to‐date data collection to properly assess and manage this formerly abundant stock. [ABSTRACT FROM AUTHOR]

Bluespotted seabream Pagrus caeruleostictus, a member of the family Sparidae, is one of the high‐priced seabream species in Ghana. Although the fish has been exploited in the Gulf of Guinea for over hundreds of years, there is scanty information on the state of the fish stock. Hence, we sought to investigate the exploitation status and aspects of the reproductive biology of the species by collecting monthly length and weight data for 18 months (February 2016 to July 2017). These data were fitted to growth and mortality models. The sexual maturity, fecundity and spawning seasons were also determined within the same period. The growth model of the fish revealed that the asymptotic length (L∞) and growth coefficient (K) values determined were 52.7 cm (total length) and 0.52 year−1, respectively. The mortality models also showed that the fishing mortality (F) of the fish was 2.20 year−1, whereas its natural mortality (M) was 0.83 year−1, with F/M > 0.5 indicating that the fish is over‐exploited. The lengths at first sexual maturity (Lm) of the males and females were 36.2 and 28.0 cm, respectively. Pagrus caeruleostictus, which was found to be highly fecund, had two spawning periods in a year, occurring in September and March, both with unimodal ova diameter frequency distributions. Based on these findings, we recommend that catch limits and other appropriate management measures (e.g. temporal and spatial closures) should be prescribed for the seabream fishery in the Gulf of Guinea to ensure the sustainability of the fishery. [ABSTRACT FROM AUTHOR]

We evaluated the potential of the euryhaline copepod Pseudodiaptomus inopinus as a prey to enhance the feeding activity of red sea bream Pagrus major larvae. Pseudodiaptomus inopinus was used to evaluate free amino acid composition and dietary effects on the rearing performance of fish larvae, in comparison to rotifers (control prey). Among free amino acids, alanine, arginine, and glycine were markedly higher in P. inopinus than in rotifers. Larvae were reared for 20 days post-hatching under three feeding treatments: rotifers (control), rotifers supplemented with copepods, and copepods only. Larvae fed copepods alone had a higher growth rate than those in the other treatments. However, the survival rates of these larvae were lower than those under control or copepod supplementation. While equivalent stocking densities of rotifers were employed in the rearing water for both larvae, whether supplemented with copepods or not, the supplemented treatment yielded diminished larval survival and failed to enhance growth rates. According to gut content analysis, larvae receiving supplemented treatment preferentially fed on copepods, and the number of ingested rotifers was reduced. As a result, total ingested mass was lower in the supplemented larvae. This study suggests that copepods containing free amino acid species negatively affect prey acceptance of fish larvae. [ABSTRACT FROM AUTHOR]

Simple Summary: Crude feed protein sources, which are rich in several amino acids, can be used as feed attractants when formulating feed. Jack mackerel meal exhibited the strongest attractiveness to red sea bream among 18 crude protein ingredients. The effects of the inclusion of various levels of jack mackerel meal in diets on the growth and feed availability of red sea bream were evaluated in an 8-week feeding trial. The results of the 8-week feeding trial proved that the dietary inclusion level of 100% jack mackerel meal in a 60%-FM-based diet produced the greatest growth performance in red sea bream, which directly resulted from the improved feed consumption. This result may imply the potential use of jack mackerel meal as a feed attractant when developing low-fish-meal diets for the sustainable culture of red sea bream. Dietary incorporation of an attractive feed protein source is a practical method of enhancing feed intake and consequently improving the growth of fish. The attractiveness of 18 crude protein sources to juvenile red sea bream (Pagrus major) and the effects of the dietary inclusion of the crude protein source that exhibited the strongest attractiveness on growth, feed availability, and economic efficiency were determined. Jack mackerel meal (JMM) showed the strongest attractiveness to red sea bream among 18 crude protein ingredients. In an 8-week feeding trial, 810 juveniles were randomly distributed into 27 tanks (30 fish/tank). Nine experimental diets were prepared. The control (Con) diet included 60% fish meal (FM). Various levels (1, 3, 5, 10, 20, 40, 60, and 100%) of JMM were included at the expense of FM in the Con diet, and the resulting diets were named the JMM1, JMM3, JMM5, JMM10, JMM20, JMM40, JMM60, and JMM100 diets, respectively. Fish were hand-fed to apparent satiation twice daily for 8 weeks. The weight gain, specific growth rate, and feed consumption of red sea bream that were fed the JMM40, JMM60, and JMM100 diets were significantly (p < 0.0001 for all) higher than those of the fish fed all other diets. However, dietary JMM inclusion had no remarkable impacts on the feed utilization, biological indices, and chemical composition of the whole body of red sea bream. In terms of the economic view of the study, the economic profit index of red sea bream fed the JMM40, JMM60, and JMM100 diets was significantly (p < 0.0001) greater than that of the fish fed all other diets. In conclusion, the strongest attractiveness to red sea bream among 18 crude protein sources was observed in JMM. The inclusion of more than 40% JMM at the expense of FM in the diet of red sea bream is highly recommended for practical feed formulations to induce remarkable improvement in the growth performance of fish and the economic returns for farmers. [ABSTRACT FROM AUTHOR]

Simple Summary: Fish meal is widely used as a feed ingredient in formulated feeds for marine fish species due to its high nutritional value and palatability. However, the increasing cost and limited availability of fish meal highlight the high need to look for an alternative protein source for fish meal in fish feeds to achieve sustainable aquaculture. Tuna by-product meal, derived from the tuna canning process, shows promise as a viable substitute for fish meal in fish feeds. This study aimed to investigate the effect of replacing fish meal with tuna by-product meal on the growth of red sea bream. The findings of this study suggested that 40% fish meal replacement with tuna by-product meal is viable without compromising growth, feed consumption, and feed utilization, while simultaneously providing the highest economic return for fish farmers. The effect of substituting fish meal (FM) by tuna by-product meal (TBM) on growth and feed availability of red sea bream (Pagrus major) was investigated. Six experimental diets were crested to be isonitrogenous (51.5%) and isolipidic (14.5%). The control (Con) diet contained 55% FM. FM substitution in the Con diet was made in increments of 20 percentage points (20, 40, 60, 80, and 100%), named as the TBM20, TBM40, TBM60, TBM80, and TBM100 diets, respectively. Juvenile red sea bream were stocked into 18, 300 L flow-through tanks (50 fish/tank). Red sea bream were hand-fed with each diet until satiation for 8 weeks. No statistical differences in weight gain, specific growth rate (SGR), and feed consumption were found among red sea bream fed the Con, TBM20, and TBM40 diets. Furthermore, feed utilization of fish fed the TBM20, TBM40, TBM60, and TBM80 diets was comparable to red sea bream fed the Con diet. The biological indices, biochemical composition, and hematological parameters of fish were not statistically altered by dietary FM replacement with TBM. The greatest economic profit index was achieved in the TBM40 diet. In conclusion, the replacement of 40% FM with TBM in red sea bream diet appears to be the most recommendable approach without producing retarded growth and feed availability, but maximizing EPI to farmers. [ABSTRACT FROM AUTHOR]

The bacterial genus Edwardsiella includes important fish pathogens that cause serious economic damage to commercial fisheries. To understand the infection cycle of bacteria of this genus, we carried out experimental infections of ayu Plecoglossus altivelis with Edwardsiella ictaluri and of red sea bream Pagrus major with Edwardsiella anguillarum, and quantified the bacteria and fish-derived materials in their rearing water by measuring environmental DNA (eDNA). The eDNA concentration of both Edwardsiella bacteria and fish in rearing water of infected fish trended upward in all experiments, and the fish eDNA concentrations of infected fish were significantly higher than those of non-infected control fish. There were significant positive correlations between eDNA concentrations of Edwardsiella bacteria and fish. Additionally, in the experiment with red sea bream, the number of skin epithelial-like cells of red sea bream in the rearing water of infected fish was significantly higher than in that of control fish, and the number of cells showed a high positive correlation with the eDNA concentration of red sea bream. These results suggest that release amounts of both Edwardsiella bacteria and fish-derived materials from infected fish increase with the progression of infection. [ABSTRACT FROM AUTHOR]

Anisakid nematodes have been found in a variety of marine fishes worldwide and they are known to cause anisakiasis and allergic symptoms in human. One-hundred and five fish specimens of different sizes of red porgy (Pagrus pagrus) were collected randomly from Sharkia fish markets originating from the Gulf of Suez, Red Sea, Egypt and examined for the presence of ascaridoid nematodes. The overall prevalence of ascaridoids was 36.19% (38/105). Four morphotypes belonging to two genera of anisakid nematodes (Anisakis type I and Terranova type II larvae) as well as one genus of raphidascarid; Hysterothylacium (larvae and adult) were reported during this study. Hysterothylacium larvae were the most predominant species (23.81%) and abundance value =1.68. Interestingly, Pagrus pagrus was found as new host and locality records for larvae of Terranova type II. The results revealed a significant statistical correlation between fish length and number of the recovered ascaridoid nematodes (rs= 0.244, P < 0.05). There was a positive correlation between the host length and presence of Anisakis type I L3 (rs=0.276, P < 0.001). Significant differences were observed between the occurrence of Terranova type II L3 and Hysterothylacium L3 occurrence (rs= 0.388, P < 0.001) and adult (rs= 0.442, P < 0.001). In addition, a highly significant relationship was observed between the presence of Hysterothylacium L3 and adult (rs= 0.428, P < 0.001). Furthermore, the obtained results were lower than the recommended Egyptian standards (-100 parasites/fish), demonstrating that human health risk through consumption of fish flesh is not possible. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus (S. aureus) is considered the most important cause of food borne intoxication, which occurs due to ingesting of food contaminated with enterotoxin of S. aureus. In this study, S. aureus from saurus, and pagrus fish species were isolated, then identified by morphological and biochemical examination. S. aureus coagulase, and D-Nase +ve were detected in 16 from 25 (64%), and 17 from 25(68%) of the examined samples of saurus, and pagrus, respectively. Total S. aureus counts were 5.14±0.06 in saurus, and 5.02±0.03 log 10 cfu/g in pagrus fish, respectively. Detection and typing of enterotoxin by Reverse Passive Latex Agglutination technique "RPLA" revealed the detection of staphylococcal enterotoxins (SEs) SEA, SEC, and SED at 18%, 6%, 0% in saurus and 5%, 0%, and 11%, at pagrus, respectively. S. aureus was tested for antimicrobial susceptibility. The recovered S. aureus coagulase, and D-Nase +ve in the current study showed resistance to kanamycin, clindamycin, nalidixic acid, and sulphamethoxazole at 100%, 87.9%, 84.8%, and 81.8%, respectively. The isolates showed sensitivity to amikacin, imipenem, meropenem, oxacillin at 90.9%, 87.9%, 84.8%, and 81.8% respectively. It could be concluded that multidrug resistant enterotoxigenic strains of S. aureus could be isolated from Saurus and Pagrus spp. Therefore, it is highly recommended to adopt strict hygienic measures and efficient cooking before consumption of such fish species. [ABSTRACT FROM AUTHOR]

This study aimed at investigation of the prevalence and antimicrobial susceptibility of Pseudomonas spp., in two marine water fish, namely Pagrus, and Saurus intended for human consumption. In the current study, Pseudomonas spp., was isolated and identified from two marine water fishes. Fifty Pagrus fish and 50 Saurus (Saurida undosquamis) fish were sampled from fish markets at Sharkia governorate, Egypt. The prevalence rates of Pseudomonas spp. were 84%, and 40% in Pagrus fish, and Saurus respectively. The identified Pseudomonas spp., from Saurus was Pseudomonas aeruginosa (P. aeruginosa), P. fluorescens, P. fragi, P. Cepacia, at 20% for each. P. alcaligenes and P. lundensis were recovered at 10%. In Pagrus, the prevalence rates were 31.3%, 56.3%, and 6.2% for P. aeruginosa, P. fluorescens, P. fragi and P. stutzeri. Seven serotypes of P. aeruginosa were identified with the serotypes O11 at the top prevalence (42.8%), and O6, O5, O1, O8 at 19.3% for each. The virulence-associated genes were lasB (Elastase B gene), exoS (Exoenzyme S) and pilB (pili gene) were detected in the recovered P. aeruginosa at 100%, 71.4%, and 28.6%, respectively. The recovered Pseudomonas species had high antimicrobial resistance to erythromycin, amoxicillin, ampicillin and gentamycin at 100%, 88.5%, 65.4%, and 50%, respectively. In conclusion, Pagrus and Saurus fish species are considered as potential sources of multidrug resistant Pseudomonas spp. [ABSTRACT FROM AUTHOR]

Karenia mikimotoi is a common species of red tide dinoflagellate that causes the mass mortality of marine fauna in coastal waters of Republic of Korea. Despite continuous studies on the ecophysiology and toxicity of K. mikimotoi, the underlying molecular mechanisms remain poorly understood. Red sea bream, Pagrus major, is a high-value aquaculture fish species, and the coastal aquaculture industry of red sea bream has been increasingly affected by red tides. To investigate the potential oxidative effects of K. mikimotoi on P. major and the molecular mechanisms involved, we exposed the fish to varying concentrations of K. mikimotoi and evaluated its toxicity. Our results showed that exposure to K. mikimotoi led to an accumulation of reactive oxygen species (ROS) and oxidative DNA damage in the gill tissue of P. major. Furthermore, we found that K. mikimotoi induced the activation of antioxidant enzymes, such as superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, in the gill tissue of P. major, with a significant increase in activity at concentrations above 5000 cells/mL. However, the activity of glutathione S-transferase did not significantly increase at the equivalent concentration. Our study confirms that oxidative stress and DNA damage is induced by acute exposure to K. mikimotoi, as it produces ROS and hypoxic conditions in P. major. In addition, it was confirmed that gill and blood samples can be used as biomarkers to detect the degree of oxidative stress in fish. These findings have important implications for the aquaculture of red sea bream, particularly in the face of red tide disasters. [ABSTRACT FROM AUTHOR]

Larvae of an unidentified Echinocephalus species were obtained from two fish species: red porgy or common seabream (Pagrus pagrus) and greater lizard fish (Saurida undosquamis) from the Red Sea. The prevalence of Echinocephalus sp. larvae in P. pagrus was 4.92% and 4.98% in S. undosquamis. The length, width, cephalic bulb, and spine shape and pattern of the larvae resembled Echinocephalus overstreeti. SSU gene sequences of larvae from P. pagrus and S. undosquamis were identical. Comparison of the SSU sequence to those available in GenBank showed that the larvae from P. pagrus and S. undosquamis are diagnosably distinct. Based on sequence similarity and published phylogenetic analysis, these larvae are most similar to an unknown species of Echinocephalus from an Australian sea snake (Hydrophis peronii). Despite morphological similarities of the Red Sea larvae to E. overstreeti, the SSU sequence differences show that they are not the same species. [ABSTRACT FROM AUTHOR]

In this study, the complete mitochondrial genome of the Taiwan tai Argyrops bleekeri was determined for the first time by next-generation sequencing. The circular mtDNA molecule was 16,646 bp in size and the overall base composition was A (27.77%), C (28.95%), G (16.60%), and T (26.68%), with a slight bias toward A + T. The complete mitogenome encoded 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes, and a control region. Phylogenetic analysis based on the 13 PCGs of the Sparidae family revealed that Argyrops appears to be most closely related to Pagrus and Parargyrops, but further research is needed. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus (S. aureus) is considered the most important cause of food borne intoxication, which occurs due to ingesting of food contaminated with enterotoxin of S. aureus. In this study, S. aureus from saurus, and pagrus fish species were isolated, then identified by morphological and biochemical examination. S. aureus coagulase, and D-Nase +ve were detected in 16 from 25 (64%), and 17 from 25(68%) of the examined samples of saurus, and pagrus, respectively. Total S. aureus counts were 5.14±0.06 in saurus, and 5.02±0.03 log 10 cfu/g in pagrus fish, respectively. Detection and typing of enterotoxin by Reverse Passive Latex Agglutination technique "RPLA" revealed the detection of staphylococcal enterotoxins (SEs) SEA, SEC, and SED at 18%, 6%, 0% in saurus and 5%, 0%, and 11%, at pagrus, respectively. S. aureus was tested for antimicrobial susceptibility. The recovered S. aureus coagulase, and D-Nase +ve in the current study showed resistance to kanamycin, clindamycin, nalidixic acid, and sulphamethoxazole at 100%, 87.9%, 84.8%, and 81.8%, respectively. The isolates showed sensitivity to amikacin, imipenem, meropenem, oxacillin at 90.9%, 87.9%, 84.8%, and 81.8% respectively. It could be concluded that multidrug resistant enterotoxigenic strains of S. aureus could be isolated from saurus and pagrus spp. Therefore, it is highly recommended to adopt strict hygienic measures and efficient cooking during before consumption of such fish species.

This study aimed at investigation of the prevalence and antimicrobial susceptibility of Pseudomonas spp., in two marine water fish, namely Pagrus, and saurus intended for human consumption. In the current study, Pseudomonas spp., was isolated and identified from two marine water fishes. Fifty Pagrus fish and 50 Saurus (Saurida undosquamis) fish were sampled from fish markets at Sharkia governorate, Egypt. The prevalence rates of Pseudomonas spp. were 84%, and 40% in Pagrus fish, and Saurus respectively. The identified Pseudomonas spp., from Saurus was Pseudomonas aeruginosa (P. aeruginosa), P. fluorescens, P. fragi, P. cepacia, at 20% for each. P. alcaligenes and P. lundensis were recovered at 10%. In Pagrus, the prevalence rates were 31.3%, 56.3%, and 6.2% for P. aeruginosa, P. fluorescens, P. fragi and P. stutzeri. Seven serotypes of P. aeruginosa were identified with the serotypes O11 at the top prevalence (42.8%), and O6, O5, O1, O8 at 19.3% for each. The virulence-associated genes were lasB (Elastase B gene), exoS (Exoenzyme S) and pilB (pili gene) were detected in the recovered P. aeruginosa at 100%, 71.4%, and 28.6%, respectively. The recovered Pseudomonas species had high antimicrobial resistance to erythromycin, amoxicillin, ampicillin and gentamycin at 100%, 88.5%, 65.4%, and 50%, respectively. In conclusion, Pagrus and Saurus fish species are considered as potential sources of multidrug resistant Pseudomonas spp.

The experiment was conducted to evaluate alternative protein ingredients in a low-fish meal (FM) diet for red seabream (Pagrus major). Twelve experimental diets were formulated. Control diet (CON) was designed to contain 60% FM. Other experimental diets were formulated by replacing 50% of FM from the CON with soy protein concentrate (SPC), corn gluten (CG), meat meal (MM), and/or chicken byproduct meal (CBM). Four diets were designed including one of SPC, CG, MM, or CBM as FM replacer and designated as SPC, CG, MM, and CBM. Six other diets were formulated by adding two ingredients as SPC and CG, SPC and MM, SPC and CBM, CG and MM, CG and CBM, or MM and CBM, and designated as SCG, SMM, SCM, CMM, CCM, and MCM, respectively. The 12th diet (MIX) was formulated by including SPC, CGM, MM, and CBM. Triplicate fish groups (50.2 ± 0.1 g) were hand-fed for 12 weeks. Weight gain (WG) of fish was significantly improved by MM and MCM diets compared to CG, SCG, CMM, and CCM diets. WG of CON, SPC, CM, SMM, SCM, and MIX groups were comparable with MM and MCM groups. The lowest WG was observed in CG and CMM groups. Feed efficiency (FE) was significantly higher in MM group compared to SPC, CG, SGC, and CMC groups. FE of MCM group was significantly higher than CG and SCG groups. Fillet linolenic acid (C18:2n–6) level in CG group was significantly higher than CON, MM, CM, SCM, CCM, and MCM groups. Serum lysozyme activity was significantly higher in MCM and MIX groups. Therefore, a high level of dietary CG reduces the growth performance and feed utilization of red seabream. A mixture of MM and CBM seems to be more efficient in replacing FM from red seabream diet. [ABSTRACT FROM AUTHOR]

Red porgy (Pagrus pagrus) is a reef-associated, economically-important, winter-spawning, protogynous Sparidae species that appears to have declined in abundance in recent years along the southeast United States Atlantic coast. We used spatially-explicit generalized additive models built with fishery-independent chevron trap (1990–2021) and video data (2011–2021) to quantify the ways in which red porgy relative abundance and mean size varied across temporal, spatial, environmental, and habitat variables. Mean red porgy relative abundance from traps declined by 77% between 1992 and 2021, and declines were similarly large (69%) on video between 2011 and 2021. The largest two-year decline in relative abundance occurred early in the COVID-19 pandemic (2019–2021)– 32% in traps and 45% on video–despite already low abundance. Highest red porgy relative abundance from traps and video occurred in deep areas (i.e., 60–100 m) between southern North Carolina and north Georgia, and red porgy preferred low relief but continuous hardbottom habitats (i.e., pavement). We confirmed recent low recruitment of red porgy in the region based on the large increase in mean length (29%) and severe (~99%) declines of juvenile red porgy caught over the 32-year trap survey. Evidence suggests that recruitment failure is partially or mostly responsible for red porgy abundance declines, and, moreover, the regulation of harvest is unlikely to achieve sustainable management goals until recruitment increases. [ABSTRACT FROM AUTHOR]

The red porgy (Pagrus pagrus) and the common dentex (Dentex dentex) are Sparidae species of high commercial value, traded in the Greek market. In some cases, fish species identification from Greek fisheries is difficult for the consumer due to the strong morphological similarities with their imported counterparts or closely related species such as Pagrus major, Pagrus caeroleustictus, Dentex gibbosus and Pagellus erythrinus, especially when specimens are frozen, filleted or cooked. Techniques based on DNA sequencing, such as COI barcoding, accurately identify species substitution incidents; however, they are time consuming and expensive. In this study, regions of mtDNA were analyzed with RFLPs, multiplex PCR and HRM in order to develop a rapid method for species identification within the Sparidae family. HRM analysis of a 113 bp region of cytb and/or a 156 bp region of 16s could discriminate raw or cooked samples of P. pagrus and D. dentex from the aforementioned closely related species and P. pagrus specimens sampled in the Mediterranean Sea when compared to those fished in the eastern Atlantic. HRM analysis exhibited high accuracy and repeatability, revealing incidents of mislabeling. Multiple samples can be analyzed within three hours, rendering this method a useful tool in fish fraud monitoring. [ABSTRACT FROM AUTHOR]

Triceracolax chrysophryenus (Roubal, Armitage & Rohde, 1983) is redescribed based on specimens of both sexes, recovered from the nasal cavity of the red sea bream, Pagrus major (Temminck & Schlegel, 1843) (Perciformes, Sparidae) in Japan. Leg 1 exopod of the female of the species is recognized to be 2-segmented. [ABSTRACT FROM AUTHOR]

The current study was planned for the isolation and identification of Vibrio spp. from fish samples (tilapia, mugil, tuna, saurus, pagrus, and shrimp) retailed in Zagazig city, Sharkia Governorate, Egypt. In addition to determine the antimicrobial susceptibility of the isolates. The PCR screening for virulence genes of V. parahaemolyticus and V. cholerae was also determined. The results in the present study revealed that the most contaminated samples with Vibrio spp. were pagrus (56%), followed by tilapia (52 %), then mugil (44 %), saurus (40 %), tuna (36 %), and shrimp (36 %). The most prevalent Vibrio spp. were V. parahaemolyticus (18.6%) followed by V. mimicus (11.3%), and V. alginolyticus (10%). V. cholerae was isolated in a percentage of 0.7%. Vibrio species in the current study were highly resistant to erythromycin (100%), ampicillin (75%), cephalothin (66.7%), sulphamethoxazole (66.7%), and amikacin (50%). PCR screening of virulence genes among various Vibrio spp. revealed that V. parahaemolyticus harbored tlh (100 %), tdh (80 %), and trh (80 %). While, V. cholerae was positive for rtxC, hylA, and ompU genes. As a result, the current data proves that Vibrio spp. contamination of fish, which displayed various degrees of antibiotic resistance. In addition, the isolated Vibrio spp. had virulent genes that could be dangerous to the consumer's health. [ABSTRACT FROM AUTHOR]

The escape trajectory (ET) of prey -- measured as the angle relative to the predator's approach path -- plays a major role in avoiding predation. Previous geometric models predict a single ET; however, many species show highly variable ETs with multiple preferred directions. Although such a high ET variability may confer unpredictability to avoid predation, the reasons why animals prefer specific multiple ETs remain unclear. Here, we constructed a novel geometric model that incorporates the time required for prey to turn and the predator's position at the end of its attack. The optimal ET was determined by maximizing the time difference of arrival at the edge of the safety zone between the prey and predator. By fitting the model to the experimental data of fish Pagrus major, we show that the model can clearly explain the observed multiple preferred ETs. By changing the parameters of the same model within a realistic range, we were able to produce various patterns of ETs empirically observed in other species (e.g., insects and frogs): a single preferred ET and multiple preferred ETs at small (20--50°) and large (150--180°) angles from the predator. Our results open new avenues of investigation for understanding how animals choose their ETs from behavioral and neurosensory perspectives. [ABSTRACT FROM AUTHOR]

We investigated the effects of different heating conditions on texture, protein composition, and extract components of red seabream Pagrus major, an important white-fleshed fish species. The heating conditions were set from the perspective of food hygiene. These conditions affected the hardness and sample thickness of the fish muscle, mainly due to the differences in the degree of actin denaturation. We found that 5′-monophosphate levels were not significantly different among the heating conditions. After heat treatment at a low-temperature long-time pasteurization (63 °C for 30 min), inosine and hypoxanthine levels were significantly higher than those after high-temperature heating treatment. Free amino acids showed almost no significant differences after heating. Fish muscle heated at a high-temperature short-time heating (85 °C for 90 s) was harder, had a stronger taste, and was perceived as preferable compared with other heated samples. These findings suggest that appropriate heat treatment conditions exist that make red seabream highly palatable. Moreover, the results suggest that tenderness is less important than other factors, such as taste, when evaluating the palatability of heated red seabream. [ABSTRACT FROM AUTHOR]

Red sea bream Pagrus major is extremely important in the aquaculture of Japan. The breeding of red sea bream, which has a history of more than half a century, can be divided into three main categories. The first is selective breeding. The Aquaculture Research Institute, Kindai University, began breeding fast-growing red sea breams in the early 1960s through mass selection. I summarized the results of the selection and characteristics of the fish in the 1990s. The second is breeding through chromosome manipulation and sex control. Two types of gynogenetic diploids (G2N) were artificially induced. Although growth and survival of G2N were inferior, the growth of heterozygous clones produced by mating G2N was comparable to normal diploids. The sex differentiation process and the induction condition of all-male groups by 17α-methyltestosterone treatment were clarified, and the percentage of females could be increased to more than 85%. The third is breeding through genetic manipulation. We first developed the microinjection method, and succeeded in increasing the percentage of edible ratio by deleting the function of myostatin gene by genome editing. Combining new technologies, such as genome editing, with the existing breeding methods mentioned above would result in faster and more effective breeding. [ABSTRACT FROM AUTHOR]

Fisheries managers are in need of quantitative tools to inform decisions regarding selection of robust management practices, prioritising research gaps and stocks to focus on, particularly where there are limited resources or data. To support these decisions, the use of Management Strategy Evaluation (MSE), that is, closed loop simulation‐testing of management procedures, is widely regarded as best practice. However, applying MSE is time‐ and computationally intensive, and requires highly skilled expertise and processes for stakeholder input and peer review. For data‐ and capacity‐limited fisheries, MSE may be particularly challenging to implement. Yet, these are the contexts where it is most critical to test assumptions, evaluate the implications of all sources of uncertainty and identify the most informative data sources. To facilitate wider use of MSE, the Method Evaluation and Risk Assessment (MERA) framework was developed as an accessible online interface, with quick processing time, focused on generic data‐limited management procedures, but allowing progression to tailored and more data‐rich methods. The framework links a quantitative questionnaire and data input standard to a flexible operating model with optional customisation via command line access to the back‐end open‐source R libraries. Here, we illustrate a case study application of MERA for the bocinegro (Pagrus pagrus, Sparidae) fishery in the Gulf of Cadiz, where in conjunction with fishery stakeholders, a custom management procedure was developed and tested and key research gaps and data collection priorities were identified. We discuss implications for wider use of MSE in various contexts, including eco‐certification and fishery improvement projects. [ABSTRACT FROM AUTHOR]

The feeding habits and habitat of different fish species influence the morphology and functions of their gill rakers. This study used gross anatomy and scanning electron microscopy to investigate the morphological features of the gill rakers in Siganus luridus, Boops boops, and Pagrus pagrus. The gill rakers appeared as medial and lateral rows in all studied fishes. Except for Pagrus pagrus, which had a unique gill rakers arrangement in which the medial row of the 4th gill arch had the most gill rakers, the longest and most gill rakers were on the 1st gill arch in all studied fishes. The gill rakers of Siganus luridus were smooth, with various spine-like shapes, such as spine-like gill rakers, which were bifid or trifid spines, or duck toe-shaped gill rakers. According to SEM of the Siganus luridus' gill rakers, the trifid end gill rakers resembled caterpillars, and the duck toe-like gill rakers had three or four finger-like spines connected by inter-spine tissue. The Boops boops had long conical gill rakers with pointed ends on the lateral sides of the 1st gill arch, and the remaining rows had short gill rakers. According to SEM of the Boops boops' gill rakers, the long gill rakers were semi-conical and only had needle-like spines on the medial surface. The short gill rakers were projected as a boat and had three different shapes based on spine distributions. Gill rakers include those with a median crest and long spine laterals, those with only lateral spines, those with usually dorsal spines, and those with long wedge-shaped spines. Pagrus pagrus' gill rakers were short, with fine-needle spines covering their tops. By SEM of the Pagrus pagrus' gill rakers, they appeared as a cylindrical elevation with spines on top. The spines were conical in shape with pointed curved or straight ends. The maximum value of the gill rakers' lengths was discovered in the lateral row of the 1st gill arch, while the minimum value was in the medial row of the 4th gill arch. As a result, this is the first study of the three fish species' gill rakers. In the studied fishes, the morphological characteristics of gill rakers demonstrated unique structural specifications in feeding behavior. [ABSTRACT FROM AUTHOR]

Interferon regulatory factors (IRFs) play crucial roles in antiviral processes, such as in the transcriptional induction of interferon (IFN) and IFN-stimulated genes (ISGs). In this study, the genes encoding IRF5 and IRF6 were identified in Pagrus major, and their expression in various organs after pathogen infection was analyzed. In the coding sequences of P. major (Pm)IRF5 and PmIRF6, the DNA binding domain, IRF association domain, and viral-activated domain were found to be highly conserved. Phylogenetic analysis revealed that PmIRF5 and PmIRF6 were most closely related to IRF5 and IRF6 of large yellow croakers. The mRNAs for PmIRF5 and PmIRF6 were constitutively expressed in all organs analyzed but were highly expressed in the liver and gills. As a result of an infection with red sea bream iridovirus, a major pathogen of red sea bream, PmIRF5 and PmIRF6 expression was significantly upregulated in the spleen and kidney. On the basis of these results, it can be concluded that IRF5 and IRF6 expression play an influential role in the immune system of red sea bream infected with viruses. [ABSTRACT FROM AUTHOR]

Acoustic conditioning taming technology is one of the key tools for controlling and managing the behavior of target organisms in marine ranching. In this study, juvenile Pagrus major (Red Seabream) were subjected to acoustic conditioning taming with 400 Hz of square–wave continuous tones for 8 days in laboratory and 15 days in an open-sea area. At the same time, the elimination of conditioned reflexes to sounds and applications in marine ranching were tested. The Gaussian model was used to regression-fit the distribution of fish in the tank, and the fitting degree was 91.79%. Good conditioning was established after four days of acoustic conditioning taming, and the efficiency index was 44.49 in the laboratory. The average response time, aggregation time, and residence time of the test group were 0.95 s, 3.35 s, and 21.15 s, respectively. The aggregation rate of the test group showed an upward trend, and it remained at 100% from the 4th day to the 8th day. It took longer to establish the conditioned response to sound in the open-sea area, and good conditioning was established after the 18th acoustic conditioning taming. Juvenile Pagrus major with established acoustic conditioning were tagged before release. On the 18th day, 0.2% of released fish swam to a sound source when the sound was played, and from the 24th day, there was no fish presence in the area near the sound source. The conditioned response of fish to sound was gradually eliminated using the negative feedback mode of playing the sound without feeding bait. After 22 negative feedback tests, the sound was no longer attractive to the fish, meaning that the "sound–food" neural connection established by the acoustic conditioning taming had been eliminated. The results of this study show that acoustic conditioning taming technology was an effective method of fish behavior control, and it is feasible to apply this technology in the construction of marine ranching systems. A number of acoustic conditioning taming devices can be established in marine ranching to continuously tame the released fish and strengthen the impact of the sound. At the same time, the multi-point deployment of automatic taming devices can form an acoustic conditioning taming network to increase the action area and effects. [ABSTRACT FROM AUTHOR]

Simple Summary: The high price and decreasing supply of fish meal (FM) has prompted the search for alternatives to achieve true sustainability in the aquaculture industry. This series of studies evaluated the complete replacement of FM by fish residue meal (FRM) in the diet of red sea bream, Pagrus major. The results revealed that FM can be completely replaced by FRM without compromising growth performance and health status. Three experiments were performed to explore (i) the complete replacement of fish meal (FM) with a combination of fish residue meal (FRM, 65% round discarded fish + 35% byproduct), soy protein concentrate (SPC) from soymilk and corn gluten meal (CGM) in Trial 1 and (ii) the utilization of diets composed of increasing byproducts in FRM in the summer (Trial 2) and winter (Trial 3) seasons. In Trial 1, the ratio of (SPC + CGM):FM in the control diet (C) was 8:2. The FM component from diet C was replaced with FRM (diet, RM20), where the ratio of (SPC + CGM):FRM became 8:2, and this ratio was changed to 6:4, 4:6 and 2:8, and referred to as RM40, RM60 and RM80, respectively. In Trials 2 and 3, the ratios of round discarded fish and byproducts in FRM were adjusted to 65:35 (FRM1), 30:70 (FRM2) and 0:100 (FRM3), and the FRM component from diet RM40 in Trial 1 was replaced with FRM1, FRM2 and FRM3 to formulate diets RM1, RM2 and RM3, respectively. In Trials 1, 2 and 3, rearing periods were 10, 8 and 12 weeks, respectively. In Trials 1 and 3, there were no significant differences in growth parameters, nutrient retention efficiency or plasma constituents among the treatments, irrespective of the inclusion levels of FRM in the diets (p > 0.05). Although there were no significant differences in final mean weight (p > 0.05), daily feeding rate and feed conversion ratio in diet RM3 were significantly higher and lower, respectively, compared to the control group in Trial 2 (p < 0.05). These results suggest that FM can be entirely replaced with FRM, and that the total elimination of round discarded fish from FRM does not affect growth or health status in red sea bream either in summer or winter seasons. [ABSTRACT FROM AUTHOR]

We replaced fish meal (FM) with porcine blood meal (BM) in red sea bream (Pagrus major) diets to examine the influence on growth performance. Four experimental diets were prepared to be isonitrogenous and isolipidic by replacing 0%, 10%, 20% and 30% FM protein with BM (BM0, BM10, BM20 and BM30, respectively). After the 8‐week feeding trial, the final mean body weight, weight gain, specific growth rate, daily feeding rate, condition factor and survival rate were not significantly different among the treatments (p > 0.05). However, feed efficiency tended to lower linearly as the dietary BM level increased, and no significant difference was observed between the BM20 and BM0 groups (p < 0.05). The protein digestibility in the BM20 and BM30 groups decreased significantly compared with that in the BM0 group (p < 0.05). Fat digestibility decreased significantly in the BM30 group than in other treatment groups (p < 0.05). The total serum protein and total cholesterol concentrations in the BM30 group were the highest among all treatment groups. In conclusion, BM can replace up to 20% of FM in the red sea bream diet without adversely affecting growth performance. [ABSTRACT FROM AUTHOR]

The red porgy (Pagrus pagrus) and the common dentex (Dentex dentex) are Sparidae species of high commercial value, traded in the Greek market. In some cases, fish species identification from Greek fisheries is difficult for the consumer due to the strong morphological similarities with their imported counterparts or closely related species such as Pagrus major, Pagrus caeroleustictus, Dentex gibbosus and Pagellus erythrinus, especially when specimens are frozen, filleted or cooked. Techniques based on DNA sequencing, such as COI barcoding, accurately identify species substitution incidents; however, they are time consuming and expensive. In this study, regions of mtDNA were analyzed with RFLPs, multiplex PCR and HRM in order to develop a rapid method for species identification within the Sparidae family. HRM analysis of a 113 bp region of cytb and/or a 156 bp region of 16s could discriminate raw or cooked samples of P. pagrus and D. dentex from the aforementioned closely related species and P. pagrus specimens sampled in the Mediterranean Sea when compared to those fished in the eastern Atlantic. HRM analysis exhibited high accuracy and repeatability, revealing incidents of mislabeling. Multiple samples can be analyzed within three hours, rendering this method a useful tool in fish fraud monitoring.

Red seabream (Pagrus major), a migratory fish, is characterized by high protein levels in the muscle. South Korean and Japanese red seabreams have a general distribution pattern; however, distinguishing them based on their geographical origin is difficult. In this study, we used capillary electrophoresis time-of-flight mass spectrometry (CE-TOF/MS) to analyze the red seabream muscle metabolome to investigate how can distinguish the origin of the fish. The metabolites were extracted using 50% acetonitrile in water. Chromatographic separation was successfully used to classify the metabolite profiles of Japanese and South Korean red seabream. Principal component analysis and hierarchical cluster analysis showed good ability to categorize the samples according to their origin. Amino acids showed the greatest quantitative difference in South Korean and Japanese muscle samples. Specifically, the L-alanine, L-glutamic acid, L-isoleucine, dimethylglycine, and L-valine levels in Japanese red seabream samples were significantly higher than those in South Korean samples. In contrast, the levels of trimethylamine N-oxide and inosine monophosphate in South Korean muscle samples were significantly higher than those in Japanese red muscle samples. The monitored metabolite profiles suggest that South Korean and Japanese red seabreams can be identified on the basis of amino acid levels. [ABSTRACT FROM AUTHOR]

The red porgy (Pagrus pagrus) is a carnivore bottom dweller sparid, inhabiting flat sandy bottoms, rhodolith and seagrass beds of the Mediterranean Sea, the Western Atlantic (from Florida to Argentina) and the Eastern Atlantic (from Britain to Gabon). Along its native range, the red porgy is highly targeted by commercial and artisanal fisheries. In the past 40 years, the population decline of the species has been widely reported. In many locations, such as the Brazilian coast, stocks have collapsed. The central portion of the Brazilian coast harbours the largest rhodolith beds in the world and the highest levels of nektonic and benthic biodiversity. Along the rhodolith megahabitat, P. pagrus density is disproportionately higher (by 480%) than that of conspicuous benthic fishes inhabiting the same environment. Despite the ecological and economic importance of such an important species along its native range, little is known regarding its habitat use, niche availability and population responses to global warming. Here we present habitat affinities based on data sampled using baited remote stereo‐video systems, and modelled niche availability and global warming populational responses. Our findings reveal that the red porgy is a species highly associated with rhodolith beds along the central portion of the Brazilian coast. The presence of a disproportional density and biomass of the red porgy, compared to other marine fish species, indicates that the species plays a key ecological role as a carnivore, mesoconsumer and prey/predator tolerant species, maintaining essential ecological functions in the habitat. In a global warming scenario, the model predicted populational niche shifts poleward and a severe niche erosion at lower latitudes as expected. Conservation initiatives (implementation of Maine Protected Areas, trawling exclusion zones, mining exclusion zones, fisheries management policies) are urgent to secure future stocks of the red porgy and also preserve the fragile rhodolith beds they inhabit. [ABSTRACT FROM AUTHOR]

Most probiotic yeast supplement in fish exhibit beneficial effect at ≤1% of the dietary proportion. This study aimed at evaluating the specific effects of Lypomyces starkeyi CB1807 yeast strain supplemented at ≤1% of dietary proportion on the performance of juvenile red sea bream (Pagrus major, 1.9 ± 0.04 g). Five diets were supplemented with yeast at graded levels of 0% (control diet 'CD1'), 0.05% (D2), 0.1% (D3), 0.5% (D4), and 1.0% (D5). After 45 days of feeding trial, significant (P<0.05) improvement was detected on final body weight (FBW) and body weight gain (BWG) in fish fed D3 and D5 compared to control. Low values of total cholesterol (T-Cho) and aspartate aminotransferase (AST) were recorded in fish groups fed on D2, D4, and D5, respectively. Fish fed on D3, D4 and D5 diets showed high (P<0.05) values of serum, mucus and liver lysozyme compared to control. Fish fed on D5 showed high values of total immunoglobulin (Ig) compared to control. Fish fed on D2 showed strong correlation with biological antioxidant activity (BAP), superoxide dismutase (SOD) and catalase activity (CAT). The biological antioxidant potential (BAP) activity in fish fed on D2 was significantly higher compared to control (P<0.05). The reactive oxygen metabolites (d-ROM) were significantly lower in fish fed on D2 and D3 compared to CD1 (P<0.05). Peroxidase activity was improved significantly (P<0.05) in fish fed on D3, D4 and D5 compared to control. The tolerance ability (LT50) of fish fed on D5 against low salinity stress was significantly higher compared to control (P<0.05). It was concluded that dietary benefits of spent L. starkeyi yeast at ≤1% showed considerable improvement in antioxidant capacity in red sea bream, P. major. [ABSTRACT FROM AUTHOR]

The harmful algal bloom species, Karenia brevis, forms annual, often intense blooms in the Gulf of Mexico, particularly along the west Florida shelf. Though the ability of K. brevis blooms to cause mass mortalities in juvenile fish are well documented, the direct effect of bloom concentrations on larval fish has not been studied extensively. To better understand the potential effect of K. brevis on larval fish survival, laboratory spawned red porgy (Pagrus pagrus) larvae from 4–26 days post-hatch were exposed to concentrations of K. brevis observed in the field for either 24 or 48 h. This species is representative of fish which spawn in regions of the Gulf of Mexico and whose larvae are epipelagic and may encounter K. brevis blooms. In this study, three different K. brevis strains varying in the amount of brevetoxin produced were tested. Larval survivorship was found to be inversely proportional to the amount of brevetoxin produced by each strain. The EC50 value from the combined 24 h experiments was ~163,000 K. brevis cells L−1, which corresponds to cell concentrations found in moderately dense blooms. Larval mortality also increased substantially in the 48 h versus 24 h exposure treatments. These findings indicate K. brevis blooms have the potential to contribute to natural mortality of fish larvae and further reduce inter-annual recruitment of fishery species whose stocks in the Gulf of Mexico may already be depleted. [ABSTRACT FROM AUTHOR]

The present research focuses on the seasonal changes in the energy content and metabolic patterns of red porgy (Pagrus pagrus) sampled in a fish farm in North Evoikos Gulf (Greece). The study was designed in an effort to evaluate the influence of seasonality in several physiological feauteres of high commercial importance that may affect feed intake and growth. We determined glycogen, lipids and proteins levels, and cellular energy allocation (CEA) as a valuable marker of exposure to stress, which integrates available energy (Ea) and energy consumption (Ec). Metabolic patterns and aerobic oxidation potential were based on the determination of g lucose transporter (GLU), carnitine transporter (CTP), L-lactate dehydrogenase (L-LDH), citrate synthase (CS), cytochrome C oxidase subunit IV isoform 1 (COX1) and 3-hydroxyacyl CoA dehydrogenase (HOAD) relative gene expression. To integrate metabolic patterns and gene expression, L-LDH, CS, COX and HOAD activities were also determined. For further estimation of biological stores oxidized during seasonal acclimatization, we determined the blood levels of glucose, lipids and lactate. The results indicated seasonal changes in energy content, different patterns in gene expression and reorganization of metabolic patterns during cool acclimatization with increased lipid oxidation. During warm acclimatization, however, energy consumption was mostly based on carbohydrates oxidation. The decrease of E c and COX1 activity in the warm exposed heart seem to be consistent with the OCLTT hypothesis, suggesting that the heart may be one of the first organs to be limited during seasonal warming. Overall, this study has profiled changes in energetics and metabolic patterns occurring at annual temperatures at which P. pagrus is currently farmed, suggesting that this species is living at the upper edge of their thermal window, at least during summer. [Display omitted] • Pagrus pagrus growth is strongly dependent on sea-water temperature. • Lower feed intake and growth rate were observed in P. pagrus during cold acclimatization. • Protein mobilization in metabolism and energy provision was also observed in winter. • Optimal temperatures for P. pagrus physiological processes are 20oC–22 °C. • White muscle energy after winter recovery is associated with carbohydrate stores. [ABSTRACT FROM AUTHOR]

The stress physiology and welfare needs of red seabream, a fish species with high nutritional and economic value for aquaculture, have been poorly studied. The aim of the current study was to investigate physiological responses of red seabream to potential environmental and husbandry stress factors. We quantified the acute stress response of fish exposed to a standardized acute chasing stress protocol as well as to transportation stress, by analysing acute stress biomarkers such as plasma concentrations of cortisol, glucose, lactate and osmolality. Moreover, the physiological status of fish reared at different water temperatures (15, 20 and 25°C) was also studied by analysing plasma parameters and cortisol concentration in scales. Results showed that in most estimated parameters, red seabream showed a fast response and recovery to acute stress. On the contrary, recovery after an 18‐h transportation stress was prolonged and required more than one day. Finally, rearing of fish at different temperatures also affected stress indicators such as plasma cortisol and glucose, while lactate and osmolality were not significantly affected. Regarding cortisol concentration in fish scales, a chronic stress indicator, results showed that fish reared at 15°C had a significantly higher cortisol concertation of scales than those exposed to 25°C. The data provide a better insight into the effect of husbandry and environmental factors on red sea bream stress physiology and welfare. [ABSTRACT FROM AUTHOR]

A 50-day feeding trial was conducted to evaluate the efficiency of single and mixed strains of probiotic bacteria supplements on juvenile red sea bream (Pagrus major). The study investigated the growth, digestibility, hemato-biochemistry, antioxidant, immune, immune, and growth gene expression and stress responses of P. major. Three hundred juvenile P. major (21.56 ± 0.09 g) were randomly distributed into fifteen 200-L polyethylene tanks (20 fish per tank) in triplicate of 5 treatments designated as D1 = the basal diet; Streptococcus faecalis (SF) T − 110 5 × 106 cfu/g diet and Bacillus amyloliquefaciens (BA) TOA 5001 5 × 105 cfu/g diet in the second group (D2) at 0.2%; mix SF T − 110 1 × 106 cfu/g diet, Lactobacillus plantarum (LP) TO − A 4 × 105 cfu/g diet, Bacillus mesentericus (BM) TO − A 1 × 102 cfu/g diet, BA TOA 5001 5 × 105 cfu/g diet in the third group (D3) at 1%; mix SF T − 110 1 × 106 cfu/g diet, LP TO − A 4 × 105 cfu/g diet, and BM TO − A 1 × 102 cfu/g diet in fourth group (D4) at 0.5%; and single strain BA TOA5001 5×105 cfu/g diet in the fifth group (D5) at 0.5% of dietary proportion. Results showed that D2 and D3 fish groups exhibit better performance, followed by D4, D5, and control group D1. This finding demonstrated that the use of BA in mix strain probiotic bacteria diet (D2, D3) had improved immune response, antioxidant enzymes, immunity (TNF-a, IL-1b), and growth-related (IGF-1, IGF-2) mRNA expression of juvenile P. major compared to the mix strain D4, single strain D5, and the control D1. Furthermore, single strain D5 and mix strain D4 also exhibit relatively better immune responses in P. major than in control D1. Considering the overall fish performances, mix strain SF+BA (D2) and mix strain SF+BM+LP+BA (D3) were the recommended potential mix strain probiotic bacteria supplement for P. major and may be useful also for other related aquatic species. [ABSTRACT FROM AUTHOR]

Black soldier fly meal (BM) is an outstanding candidate as a fish meal (FM) substitute because it contains relatively high protein and essential amino acids. In this study, we replaced FM in red sea bream diets (Pagrus major) with BM to investigate its effect on growth and feed utilization. Six isonitrogenous and isolipidic experimental diets were prepared by substituting 0%, 20%, 40%, 60%, 80% and 100% FM protein with BM (Control, BM20, BM40, BM60, BM80 and BM100, respectively). After the 8‐week feeding trial, final body weight, weight gain, specific growth rate and feed efficiency decreased linearly with increasing dietary BM level (p < 0.05). Apparent digestibility of protein and fat and serum total cholesterol concentration decreased with increasing dietary BM levels (p < 0.05) Final body weight, WG, SGR and FE against dietary BM level had breaking points of 76.2%, 41.7%, 76.5% and 60.0%, respectively, in segmental regression analysis. In conclusion, the results suggest that BM can replace a maximum of 41.7% of FM in the diet of red sea bream without compromising growth performance or feed efficiency for 56 days. [ABSTRACT FROM AUTHOR]

A feeding experiment was conducted to survey proper microalgae species for nonfish meal and non-fish oil diet of red sea bream. Five iso-nitrogenous and iso-lipidic diets were formulated (CP 47%, CL 19%). Fish oil formulated non-fish meal diet was arranged as a control diet with soybean meal, soy protein concentrate and corn gluten meal (FO). Fish oil of FO was replaced by Nannochloropsis meal and Schizochytrium meal for each of two diets (NAN, SCH). Both microalgae meals were mixed in a diet (NS), and Chlorella meal was formulated in NS diet to replace plant protein source (NSC). Duplicated groups of juvenile red sea bream (5.9 g) were fed the experimental diets for 75 days to near satiation. The growth was the highest in NS and NSC diet group. The other algae meal formulated diets fed groups showed the similar growth performance to FO. In fatty acid profiles, NAN group showed the lowest n-3 LC-PUFA with low DHA content in fatty acid composition of total lipid in fish carcass and hepatic PL, but the other algae meal diet group showed no significant difference with FO group. The results might suggest blending microalgae and using them with high amount is a key strategy for development of non-fish meal and non-fish oil diet for red sea bream. [ABSTRACT FROM AUTHOR]

The optimum level of fishmeal (FM) protein replacement by bacterial protein meal (BPM) was determined in the diet of juvenile red sea bream, Pagrus major. Six isoproteic and isolipidic diets were formulated to replace 0 (control diet), 190 , 280, 370, 470 and 560 g of the FM protein kg‐1 diet with BPM protein, and referred to as C, BP19, BP28, BP37, BP47 and BP56, respectively. Each diet was fed to triplicate groups of twenty fish (mean weight ~43 g) twice per day to apparent satiation. Fish fed diets C and BP19 did not show significant differences (p >.05) in growth, apparent digestibility or protein and lipid retention efficiency, but the daily feeding rate (DFR) was significantly lower under BP19 than under C. However, almost all growth parameters were significantly reduced when FM protein replacement with BPM was further increased from 280 to 560 g kg‐1 diet (p <.05). The results of polynomial regression analysis (second‐order) revealed significant negative correlations between dietary copper levels and final mean weight (R2 =.913), specific growth rate (R2 =.913) and DFR (R2 =.956). The results indicated that BPM could replace approximately 190 g of FM protein kg‐1 diet in the juvenile red sea bream diet without compromising growth performance or feed efficiency. [ABSTRACT FROM AUTHOR]

Some marine fish are stored alive without feeding at the market before being shipped on demand. To investigate the effect of live fish storage in diluted seawater (DSW) on the postmortem changes of extractive components of ordinary muscle from live red seabream Pagrus major stored in DSW, seawater (SW), and cultured in sea-surface culture cages (Control) were compared. Prior to ice storage, only phenylalanine showed a significant difference between DSW and Control, whereas eight extractive components, inosine-5′-monophosphate, and total amounts of free amino acids were significantly different between SW and Control. During the 21 days of storage, differences in five extractive components were observed between DSW and Control, whereas differences in nine extractive components, non-protein nitrogen, and total amounts of free amino acids were observed between SW and Control. Before storage, hierarchical clustering classified DSW and Control in the same cluster, separate from SW. After storage, most of the Control and SW samples belonged to different clusters, and DSW samples overlapped with Control and SW clusters. Thus, it is concluded that live storage in diluted seawater could maintain the profiles of extractive components of control before and after ice storage, better than those of SW. [ABSTRACT FROM AUTHOR]

Triceracolax pagri Izawa, 2021 is redescribed on the basis of specimens of both sexes recovered from the bucco-branchial cavity of the original host, Pagrus major (Temminck & Schlegel, 1843). Both sexes of copepodid IV and the male copepodid III, collected together with the adults, are described for the first time, and sexually dimorphic features in late copepodid stages are discussed. Résumé: Triceracolax pagri Izawa, 2021 est redécrite à partir de spécimens des deux sexes prélevés dans la cavité bucco-branchiale de l'hôte original, Pagrus major (Temminck & Schlegel, 1843). Les deux sexes du copépodite IV et le copépodite III mâle, collectés ensemble avec les adultes, sont décrits pour la première fois, et des caractères sexuellement dimorphiques des derniers stades copépoditiques sont discutés. [ABSTRACT FROM AUTHOR]

A pleuronectiform fish, the barfin flounder Verasper moseri, has three forms of gonadotropin-releasing hormone (GnRH) in the asymmetric brain: GnRH1 (seabream GnRH), GnRH2 (chicken GnRH-II), and GnRH3 (salmon GnRH). To determine whether the levels of GnRH differ between the ocular and blind sides of the forebrain of barfin flounder, we examined the distribution pattern of GnRH using time-resolved fluoroimmunoassays. Red seabream Pagrus major, which has a symmetric brain and three forms of GnRH, was used as a control. In contrast to red seabream, barfin flounder showed an imbalance in the weight of the forebrain (olfactory bulbs, telencephalon, and optic tectum-thalamus), with the ocular side (right side) significantly larger than the blind side (left side). In barfin flounder, there were significantly higher contents (pg/tissue) of the three forms of GnRH in the olfactory bulbs and optic tectum-thalamus in the ocular side of brain than in the blind side. In the telencephalon, GnRH2 content was significantly higher in the ocular side of brain. However, the contents of both GnRH1 and GnRH3 were not significantly different between the ocular and blind sides of the telencephalon, although those in the ocular side tended to be higher than those in the blind side. In red seabream, no difference in the contents of the three forms of GnRH was found between the right and left sides. Concentrations (pg/mg tissue) of the three forms of GnRH did not differ between the ocular and blind sides of the barfin flounder brain, as is the case of red seabream. These results suggest that in the barfin flounder, despite the ocular and blind sides of the forebrain differing in terms of brain volume, there are no functional or qualitative differences in the levels of the three GnRH forms because their tissue concentrations were the same on both sides. [ABSTRACT FROM AUTHOR]

This study was performed to assess, by molecular methods, the gut microbial community associated with early life stages of the reared red seabream (Pagrus major). This work sought to better understand the gut microbiota during seed production, which may help control disease in the near future. At the larval fish stage, Alphaproteobacteria, Flavobacteria, and Gammaproteobacteria (excluding Vibrionaceae) were predominant in fish guts. These bacteria also predominated in rotifers, the primary component of the larval fish diet. At the juvenile stage, Gammaproteobacteria, Alphaproteobacteria, and Flavobacteria (except for Flavobacteria in one of two juvenile libraries) were predominantly detected in fish guts. Again, these bacteria also predominated in Artemia nauplii, a main component of the juvenile fish diet. These results suggested that the gut microbiota of larval and juvenile red seabream is influenced primarily by the microbiota of their diets. On the other hand, members of the family Vibrionaceae were not detected in larval fish guts, the rearing seawater, or rotifers, whereas bacteria of this family represented 28.6-64.6% of the reads in two libraries of juvenile fish guts. These observations suggested that hygiene management and administration of probiotics at the early life stage of red seabream are effective in suppressing the onset of opportunistic infections. [ABSTRACT FROM AUTHOR]

Considering the high nutritional value of fish as food, in combination with the worldwide problem of overfishing, aquaculture constitutes a major sector of economic activity. Consumers of marine products are affected by the appearance and particularly of the fish colour. In this context, the coloration of the final product represents an important criterion for its final selection. The European Food Safety Authority has enacted a legislation regarding coloration in food. Although colour on the skin of fish is principally genetically determined, fish are unable to produce colour pigments. Therefore, diet is directly related to colour and the most common pigment is carotenoids. One of the most successful examples of aquaculture, in terms of skin coloration, is the red porgy Pagrus pagrus. Concerning the achievement of its colour, concatenated data from different studies show that the most effective method is the combination of two factors: diet with astaxanthin and maintenance of fish in short‐term periods in white background before sale. Moreover, alternative and effective ways for achievement of the desired colour are the submerged cages and the in sea cages with canopies. However, knowledge about carotenoids regarding fish coloration is scarce. Thus, future research is needed in order to elucidate the underlying mechanisms concerning the chromatic plasticity in the skin of fish. [ABSTRACT FROM AUTHOR]

Polymorphisms of growth- and immune-related genes in cultured red sea bream Pagrus major identified by gene-related DNA markers Keywords: domestication; gene-related microsatellite; outlier; Pagrus major; red sea bream EN domestication gene-related microsatellite outlier Pagrus major red sea bream 410 416 7 05/20/21 20210601 NES 210601 INTRODUCTION Red sea bream, I Pagrus major i , is an important farmed marine fish in Japan, cultured for nearly half a century. However, growth is known to be a polygenic trait (Tsai et al., 2015), and other growth-related genes such as the I GH i receptor gene and insulin-like growth factor genes ( I IGF-I i and I -II i ) may have been subject to selection pressure during domestication. All gene-related markers showed lower numbers of alleles in domestic populations (mean 6.7 in growth-related and 7.4 in immune-related genes) compared to wild (mean 15.6 in growth- and 17.5 in immune-related genes). [Extracted from the article]

Natural mortality (M) is a powerful parameter in fisheries stock assessment and management; however, its precise estimation is extremely difficult. There is still a lack of estimates for several stocks. That is the case of demersal/deep-water species from the Azores archipelago, where demersal species are the second most important fishery based on landings and the most important in value. Species with higher commercial value and lacking M data were selected: Pagellus bogaraveo, Phycis phycis, Beryx splendens, Pontinus kuhlii, Helicolenus dactylopterus, Pagellus acarne, Beryx decadactylus and Pagrus pagrus. Life history parameters were gathered from literature. A literature review was performed to summarize all published indirect methods that are commonly used, as a simple and low-cost way to estimate M. This study aims to demonstrate the variability of natural mortality estimates based on the input parameters. It also constitutes the first attempt of M estimation for the most commercially important Azorean species. Twenty-six indirect methods were applied and about 70 % of the selected species had an average mortality estimate between 0.22 and 0.34 per year. The most well-studied species (Pagellus bogaraveo and Helicolenus dactylopterus) provided more accurate mean estimations (M = 0.30 and M = 0.27, respectively). Independent methods based on Tmax alone, or combined with L∞ or W∞, lowered the values. Methods based on reproduction parameters alone, or combined with growth, inflated the estimations. From the selection of life history parameters to the final estimation of M, the results of this study can fill the existing gap and represent a starting point for further studies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Red seabream faces origin labeling issues after the Fukushima disaster. • We aimed to develop biomarkers to discriminate between Japanese and Korean seabream. • We used fatty acids, amino acids, minerals analysis to determine the origin of fish. • We analyzed 29 fatty acid families, 17 amino acids, and 4 minerals in 60 samples. • Among the top 10 distinct fatty acids, linoleic acid emerged as a precise biomarker. Red seabream (Pagrus major) has been one of the most popular fish in East Asia since early times. However, the discharge of nuclear wastewater into the sea following the Fukushima nuclear disaster in Japan has led to violations of the country of origin labeling. Therefore, the aim of the present study was to determine the origin of fish based on fatty acid, amino acid, and mineral analyses, and to develop biomarkers that can discriminate between Japanese and Korean red seabream. To identify the differences between the two groups, 29 fatty acid families, 17 amino acids, and 4 minerals were analyzed in 60 fish samples (standard sample collected in autumn), and fatty acid profiles were analyzed using heatmap with hierarchical clustering analysis and orthogonal projections to latent structures discriminant analysis. The top 10 fatty acids that were different between the two groups were selected from all seasonal fish samples by combining variable importance in projection scores and p-values. According to the receiver operating characteristic curve analysis results, we proposed percentage linoleic acid (C18:2n-6, cis) as a candidate biomarker with excellent sensitivity and specificity. This study introduces a strategy to identify the origins of red seabream using linoleic acid obtained from fatty acid analysis. [ABSTRACT FROM AUTHOR]