Juvenile Red Sea Bream Pagrus Research Articles

Identification of the causative gene of a transparent phenotype of juvenile red sea bream Pagrus major.

Deformities in cultured fish species may be genetic, and identifying causative genes is essential to expand production and maintain farmed animal welfare. We previously reported a genetic deformity in juvenile red sea bream, designated a transparent phenotype. To identify its causative gene, we conducted genome-wide linkage analysis and identified two single nucleotide polymorphisms (SNP) located on LG23 directly linked to the transparent phenotype. The scaffold on which the two SNPs were located contained two candidate genes, duox and duoxa, which are related to thyroid hormone synthesis. Four missense mutations were found in duox and one in duoxa, with that in duoxa showing perfect association with the transparent phenotype. The mutation of duoxa was suggested to affect the transmembrane structure and thyroid-related traits, including an enlarged thyroid gland and immature erythrocytes, and lower thyroxine (T4) concentrations were observed in the transparent phenotype. The transparent phenotype was rescued by T4 immersion. Loss-of-function of duoxa by CRISPR-Cas9 induced the transparent phenotype in zebrafish. Evidence suggests that the transparent phenotype of juvenile red sea bream is caused by the missense mutation of duoxa and that this mutation disrupts thyroid hormone synthesis. The newly identified missense mutation will contribute to effective selective breeding of red sea bream to purge the causative gene of the undesirable phenotype and improve seed production of red sea bream as well as provide basic information of the mechanisms of thyroid hormones and its related diseases in fish and humans.

Acute Toxicity of Chlorine Dioxide (ClO 2 ) to Juvenile Black Seabream Acanthopagrus schlegelii and Red Seabream Pagrus major

Acute Toxicity of Chlorine Dioxide (ClO 2 ) to Juvenile Black Seabream Acanthopagrus schlegelii and Red Seabream Pagrus major

Periodic changes in the growth performance and biochemical composition of juvenile red sea bream Pagrus major fed non-heated and heated squid and krill meal-based diets

In finfish aquaculture, fish meal is heated during the manufacturing process, which affects the digestibility and protein absorption by fish. However, manufactured fishmeal that is not heated does not undergo thermal denaturation. Few studies have investigated the effects of non-heated animal protein sources on the growth performance of fish. We investigated the effects of heated and non-heated squid and krill meal as diets for red sea bream. Five test diets were formulated to contain heated squid meal, non-heated squid meal, heated krill meal, non-heated krill meal, and fish meal as a control. Fifty fish (initial mean weight = 3.5 g) were distributed in ten 100-l experimental tanks. Fish were fed one of the five diets 3 times daily until satiation for 5 weeks. Regarding growth performance, fish fed the krill meal diet exhibited better growth than those fed squid meal during the first week of the rearing period. However, the squid meal diet group showed better performance than the krill meal diet group during the third week. Moreover, differences in body weight among treatments were greater during the fifth week. Better weight gain and thermal growth coefficient were recorded in the non-heated diet groups than in the heated diet groups. Higher feed intake was observed in the non-heated diet groups than in the heated diet groups. These results suggest higher performance of non-heated squid and krill meal as the protein source of the red sea bream diet. Further, the suitability of the diet type (e.g., squid and krill) might depend on the feeding period and/or developmental stage of fish.

Evaluation of gastric evacuation and digestion of extruded pellet composed of a single protein source for juvenile red seabream Pagrus major

Evaluation of gastric evacuation and digestion of extruded pellet composed of a single protein source for juvenile red seabream Pagrus major

Effects of alcohol treatment of dietary soybean meal on growth performance and hepatopancreatic histology of juvenile red sea bream Pagrus major

Effects of alcohol treatment of dietary soybean meal on growth performance and hepatopancreatic histology of juvenile red sea bream Pagrus major

Effects of Taurine, Phytase and Enzyme Complex Supplementation to Low Fish Meal Diets on Growth of Juvenile Red Sea Bream Pagrus major

Effects of Taurine, Phytase and Enzyme Complex Supplementation to Low Fish Meal Diets on Growth of Juvenile Red Sea Bream Pagrus major

Dietary valine requirement of juvenile red sea bream Pagrus major

A 12-week feeding trial was conducted to determine dietary valine requirement of juvenile red sea bream (Pagrus major). Six isonitrogenous (45% crude protein) and isocaloric (4.38kcalg−1 gross energy) semi-purified diets were formulated with graded levels of valine (0.27, 0.79, 1.22, 1.69, 2.04 and 2.38% dry diet). Triplicate groups of fish (32.04±0.2g) were fed one of the diets to apparent satiation twice daily. At the end of the feeding trial, significantly (P<0.05) higher growth performance and feed utilization were obtained at dietary valine levels of ≥0.79% compared to fish fed 0.27% valine. Significantly lower whole-body moisture and higher protein contents were recorded at over 0.79% valine level and lipid content increased in fish fed 2.04% valine. Non-specific immune responses of fish were significantly improved by increment of dietary valine up to 2.04%. Plasma total protein, aspartate aminotransferase and total cholesterol levels were significantly affected by valine levels. Significantly lower postprandial ammonia excretion levels were obtained in fish fed dietary valine levels of 1.69 and 2.04% compared to the fish offered 0.27% valine. The optimum dietary valine requirement level was estimated at approximately 0.9% of dry diet (2% of dietary protein) by a broken-line regression analysis on the basis of weight gain and protein deposition.

Dietary arginine requirement of juvenile red sea bream Pagrus major

Abstract A 9-week feeding trial was carried out to evaluate dietary arginine requirement of juvenile red sea bream. Six isonitrogenous and isocaloric diets (50% crude protein and 17.7 kJ g− 1 gross energy) were formulated to contain graded levels of arginine including 1.42, 1.88, 2.22, 2.54, 3.08 and 3.43% of diet (2.84–6.86% of dietary protein), and fed triplicate groups of fish (13.3 ± 0.2 g) to apparent satiation twice daily. At the end of the feeding trial, fish fed ≥ 2.22% arginine showed significantly (P

Effects of Eucheuma denticulatum Supplementation on Performance and Blood Chemistry of Juvenile Red Sea Bream Pagrus major

Effects of Eucheuma denticulatum Supplementation on Performance and Blood Chemistry of Juvenile Red Sea Bream Pagrus major

Role of taurine deficiency in inducing green liver symptom and effect of dietary taurine supplementation in improving growth in juvenile red sea bream Pagrus major fed non-fishmeal diets based on soy protein concentrate

This study was conducted to investigate the mechanism of green liver symptom induction and the effect of dietary taurine supplementation on growth performance in juvenile red sea bream fed non-fishmeal diets based on soy protein concentrate (SPC). Juvenile fish (initial BW 72 g) were fed for 20 weeks on SPC diets supplemented with taurine at levels of 0, 1.0, and 2.0%. In the taurine-unsupplemented SPC diet group, specific growth rate (SGR) and feed conversion ratio (FCR) were significantly inferior (P < 0.001), and incidence of green liver was observed in 70% of fish. In this group, hepatopancreatic and plasma taurine concentrations were lowest (P < 0.05), hepatopancreatic content of bile pigments was highest (P < 0.05), and osmotic tolerance of erythrocytes was inferior (P < 0.05) among the dietary treatment groups. Serum osmolality of all treatment groups was at similar levels. These physiological abnormalities as well as SGR and FCR were improved by dietary taurine supplementation. These results indicate that the mechanism for induction of green liver symptom is bile pigment overproduction due to increased hemolysis because erythrocytes become osmotically fragile due to dietary taurine deficiency. Taurine supplementation of SPC diets is essential for maintaining normal physiological condition and growth performance in juvenile red sea bream.

Growth, nutrient utilization, oxidative condition, and element composition of juvenile red sea bream Pagrus major fed with fermented soybean meal and scallop by-product blend as fishmeal replacement

A feeding trial was conducted to evaluate the effect of fermented soybean meal and scallop by-product blend (3:2) (FP) on the performance of juvenile red sea bream. Five isocaloric diets were prepared by replacing 0% (FP0), 15% (FP15), 30% (FP30), 45% (FP45), and 60% (FP60) fishmeal (FM) protein with FP, respectively. Triplicate groups of fish (initial mean weight 2.83 g) were fed the test diets for 45 days in a flowthrough seawater system. The results demonstrated that growth rates of fish fed FP0, FP15, and FP30 were similar, and significantly higher (P < 0.05) than those of FP45 and FP60. Nutrient utilization was significantly lower in FP60, with no differences found among the other groups. Dietary heavy-metal contents were affected by inclusion of FP, impacting on whole-body heavy-metal contents. In terms of oxidative stress, fish fed the FP30 diet were in the best condition, since this fish group showed the least oxidative-stressed condition as well as the highest tolerance against oxidation. In conclusion, the approach of utilizing this fermented mixture is promising and it could replace at least 30% FM protein in red sea bream diet without negative effects on performance, body composition or health of fish.

Effects of Temperature and Stocking Density on the Ammonia Excretion Rate of Red Seabream, Pagrus major

An experiment was conducted to investigate the effects of temperature and stocking density on daily patterns and rates of total ammonia nitrogen (TAN) excretion in juvenile red seabream Pagrus major (mean body weight: 29.0 g) under fasting and feeding conditions. Fish were acclimated over 7 days under four different temperatures (10, 15, 20, and <TEX>$25^{\circ}C$</TEX>) and at two different densities (5.5 and <TEX>$11.0\;kg\;m^{-3}$</TEX>). Each treatment had three replicates and a total of 216 fish were used. After 72 hours starvation, endogenous TAN excretion was measured for each temperature and density. To investigate exogenous TAN excretion, fish were handfed a commercial diet containing 51.6% crude protein twice a day for 7 days, at 08:00 and 16:00. Water was sampled from both inlets and outlets of chambers every 2 hours over a 24 hour period. Both endogenous and exogenous TAN excretion increased with increases in temperature and density (P<0.05). Mean daily endogenous TAN excretion rates at 10, 15, 20, and <TEX>$25^{\circ}C$</TEX> were 88.8, 101.1, 125.0, and <TEX>$143.3\;mg\;TAN\;kg^{-1}\;d^{-1}$</TEX> at low density, and 105.2, 119.2, 141.5, and <TEX>$168.8\;mg\;TAN\;kg^{-1}\;d^{-1}$</TEX> at high density, respectively. Mean daily exogenous TAN excretion rates at 10, 15, 20, and <TEX>$25^{\circ}C$</TEX> were 343.5, 403.7, 535.7, and <TEX>$601.7\;mg\;TAN\;kg^{-1}\;d^{-1}$</TEX> at low density, and 391.9, 479.7, 611.9, and <TEX>$683.4\;mg\;TAN\;kg^{-1}\;d^{-1}$</TEX> at high density, respectively. The exogenous TAN excretion rate peaked 10~12 hours after the first feeding under all temperatures and densities. The TAN loss for ingested nitrogen increased with increases in temperature and density (P<0.05), ranging from 27.9 to 50.1% at low density and 31.7 to 56.9% at high density. This study provides empirical data for estimating ammonia excretion and managing the culture of red seabream under the given temperatures and densities.

Dietary Lactosucrose Affects Calcium Content in Scales of Juvenile Red Sea Bream Pagrus major under Artificial Rearing

Some dietary oligosaccharides increase bone calcium content, often depending on hind- gut fermentation of the saccharide in mammals. Dietary lactosucrose, an indigestible and ferment- able oligosaccharides, also stimulates osteogenesis in mammals. This sugar is also fermented by gut microbes of a teleost, red sea bream Pagrus major. However, we do not know the effect of this sugar on the calcium metabolism of teleosts. If dietary lactosucrose affects calcium metabolism in the fish, calcium content in the bone or scales should be modified by this saccharide. Therefore, we tested the effect of dietary lactosucrose on calcium content of vertebrae and scales in red sea bream under artificial rearing for four months. Since the lactosucrose product we added to the diet included 57% lactosucrose and 20% lactose, we added a lactose-fed group to elucidate the influence of lactosucrose by itself. Fish fed lactosucrose had lower body weight gain than those fed control or lactose diet. Fish fed lactosucrose had greater calcium content in scales than did control fish. However, fish fed lactose had greater vertebral calcium and indifferent scale calcium when com pared with control fish. The above results suggest that dietary lactosucrose, but not the associated lactose, increased calcium concentration in scales. It is likely that indigestible and fermentable sac harides such as lactosucrose increase calcium retention in the hard tissue not only in mammals but also in marine teleosts.

Optimum dietary taurine level in casein-based diet for juvenile red sea bream Pagrus major

This study was conducted to investigate the effect of dietary taurine and cholyltaurine (C-tau) on growth and body composition of juvenile red sea Bream Pagrus major. Semi-purified casein-based diets supplemented with 0 (control diet), 0.1, 0.3, 0.5 and 0.7% taurine and 0.5% C-tau were fed to red sea bream (average body weight 4.7g) for 6 weeks at 20°C. The growth and feed efficiency were the lowest in fish fed the control diet. Taurine supplementation improved the growth and feed efficiency of fish dose-dependently, and the taurine requirement was estimated as 0.52% in terms of optimizing growth and 0.48% in terms of optimizing feed efficiency. Taurine content in the whole body and liver increased with the dietary taurine level. Supplemental C-tau at the 0.5% level had limited effects on the growth and no effect on body taurine, biliary bile salt and liver fat contents. From these results it can be inferred that the optimal dietary taurine requirement of juvenile red sea bream is 0.5% on a dry weight basis, and that the supplementation of taurine in the diet not only improves the growth but also increases hepatic lipid levels of red sea bream juveniles.

Effect of dietary taurine and cystine on growth performance of juvenile red sea bream Pagrus major

Two experiments were conducted to investigate the effect of dietary taurine and cystine on growth and body composition of juvenile red sea bream Pagrus major. In Experiment I, a casein-based semi-purified diet included a small amount of fish meal were supplemented with taurine at the levels of 0 (control) and 1.0%. The experimental diets in Experiment II were without fishmeal and supplemented with taurine at 0 (control), 0.5, 1.0 and 2.0% or cystine at 1.0 and 2.0%. These diets were fed three times a day for 6 weeks to fish (average body weight: 2.3 g in Experiment I and 2.5 g in Experiment II). In Experiment I, fish fed the taurine-supplemented diet showed significantly (P<0.05) improved growth, feed efficiency and feed consumption relative to fish fed the unsupplemental diet. The whole body taurine content increased, whereas the non-essential amino acid contents decreased, in fish fed the taurine-supplemental diet compared to fish fed the unsupplemented diet. In Experiment II, the growth, feed efficiency and feed consumption of fish fed the taurine-supplemented diets, irrespective of the dietary taurine levels, were significantly higher than those of fish fed the control diet and the cystine-supplemented diets. Taurine content in the whole body increased with the dietary taurine level, while the taurine contents did not increase by the supplemental cystine. Other free amino acid contents in the taurine-supplemented diet groups followed similar trends to those in Experiment I. These results indicate that supplemental taurine to a casein-based semi-purified diet at more than 0.5% improved the growth and feed performance of juvenile red sea bream. It is also suggested that juvenile red sea bream cannot metabolize cystine into taurine.

Dietary medicinal herbs improve growth and some non-specific immunity of red sea bream Pagrus major

The effects of dietary medicinal herbs on growth and some non-specific immunity were investigated in juvenile red sea bream Pagrus major. The fish (mean body weight 24.0±0.2g) were fed fishmeal diets supplemented with either Massa medicata (Mm), Crataegi fructus (Cf), Artemisia capillaries (Ac), Cnidium officinale (Co), or a mixture of all the herbs (HM), and a control diet without medicinal herbs, for 12 weeks. Survival, specific growth rate, feed efficiency, condition factor and hemoglobin levels were higher in fish given herbal diets than fish given the control diet without herbs. Significantly higher serum high density lipoprotein-cholesterol level and lysozyme activity were detected in HM and Co diet groups, and alternative complement pathway activity was detected in the HM diet group. However, significantly lower serum alanine aminotransferase and aspartate aminotransferase activities were obtained in all herbal diet groups compared with the control diet group. Pathogen challenge test by intraperitoneal injection of Vibrio anguillarum indicated that highest survival was obtained in the HM diet group followed by Ac, Co, Cf, and Mm diet groups. The lowest survival was obtained in the control group. These results reveal that medicinal herbs in diets enhance growth and some non-specific immunity of red sea bream.

Territorial behavior in juvenile red sea bream Pagrus major and crimson sea bream Evynnis japonica

: The territorial behavior of juvenile red sea bream Pagrus major and crimson sea bream Evynnis japonica was examined at Morode Cove, Ehime Prefecture. Four exclusive types of behavior (attack, mutual attack, head down threat and mutual display) and one escaping behavior (fleeing) were observed in both species. Juvenile of the two sea bream could discriminate between each other and change their territorial behavior depending on the presence of conspecifics or heterospecifics. The territorial behavior toward conspecifics was more aggressive than toward heterospecifics. Interrelationships between the two sea bream were more aggressive than in other heterospecific cases. The two sea breams performed following behaviors toward solo and schooled mullid species. E. japonica ascended the water column more frequently than P. major in high frequency. The former joined conspecific aggregations foraging for planktonic animals around their territories. These observations suggest that territorial individuals of the two sea bream could discriminate intruders utilizing similar food resources in order to maintain their territories.

Effect of dietary fatty acids on lipoprotein lipase gene expression in the liver and visceral adipose tissue of fed and starved red sea bream Pagrus major

Juvenile red sea bream Pagrus major were fed either a commercial diet (diet 1) or diets supplemented with 10% oleate (diet 2), 5% oleate+5% linoleate (diet 3) or 5% oleate+5% n-3 polyunsaturated fatty acid mixture (diet 4) for 4 weeks. Following the conditioning period, the effects of dietary fatty acids on lipoprotein lipase (LPL) gene expression in the liver and visceral adipose tissue of fed (5 h post-feeding) and starved (48 h post-feeding) fish were investigated by competitive polymerase chain reaction. Fish liver showed substantial LPL mRNA expression that is not found in adult rat liver. When compared with diet 1, diets 2–4 tended to increase the LPL mRNA level in the liver, but tended to decrease it in the visceral adipose tissue under the fed condition. The reciprocal regulation of the liver and visceral adipose LPL mRNA abundance by dietary fatty acids was comparable to that of rat brown and white adipose tissue, respectively. The change in the LPL mRNA level by fatty acids was not completely consistent with the degree of fatty acid unsaturation. Our results indicate that the regulatory effect of dietary fatty acids on LPL gene expression was tissue-specific and related to feeding conditions, but was not solely dependent on the degree of unsaturation of fatty acids.

Influence of dietary fat and adiposity on feed intake of juvenile red sea bream Pagrus major

A two-phase experiment was conducted to examine the effects of dietary fat and adiposity on feed intake of red sea bream. In Phase 1, juveniles (9.7 g, 20 fish tank −1, 4 replicates) were fed low fat (LF; 15.3% fat, 60.6% protein, 22.2 kJ g −1 energy, 0.61 g ml −1 density) or high fat (HF; 24.6% fat, 54.9% protein, 24.2 kJ g −1 energy, 0.68 g ml −1 density) diets for 4 weeks to produce fish which differed in adiposity. In Phase 2, all groups were fed the LF and HF diets alternately for 8 days. Fish were fed to apparent satiation by hand twice daily and daily feed consumption was recorded. Fish were weighed at the start, weekly during Phase 1 and at the end of Phase 2. Proximate composition was determined at the start of the experiment and after Phase 1 and 2. In Phase 1 the amount (18.6±0.35 vs. 17.1±0.19 g) and volume (30.6±0.58 vs. 25.2±0.28 ml) of feed consumed was significantly greater in fish fed the LF diet; energy intakes (LF, 412±7.8; HF, 413±4.7 kJ) and terminal mean fish weights (LF, 28.2±0.5; HF, 27.7±0.1 g) were similar. Fish fed the HF diet had a significantly higher proportion of visceral (37.6±1.5 vs. 28.9±1.2%) and carcass fat (9.7±0.3 vs. 8.0±0.3%). In Phase 2, fish fed the LF diet in Phase 1 consumed more of both the LF diet (2.9±0.2 vs. 2.4±0.1 g, P<0.05) and HF diet (3.2±0.1 vs. 2.9±0.1 g, P<0.07). Within each treatment fish consumed equal volumes of HF and LF feed, but the fish fed the LF diet in Phase 1 consumed a significantly greater total volume of feed (9.5±0.4 vs. 8.1±0.3 ml). Fish weights at the end of Phase 2 did not differ (LF, 34.6±0.9 vs. HF, 33.8±0.4). Our results indicate that the fish ate to meet an energy demand during Phase 1 and suggest that stomach volume increased in fish fed the lower energy (LF) diet, allowing increased meal size. This increase in meal size persisted when these fish were fed alternating HF or LF diets for 8 days (Phase 2). We were unable to unequivocally demonstrate an effect of adiposity on appetite during Phase 2, although this can be inferred since the fish fed the HF diet in Phase 1 should also have had the ability to increase their feed intake during Phase 1, but did not.

Lysine requirement of juvenile Japanese flounder Paralichthys olivaceus and juvenile red sea bream Pagrus major

The lysine requirement of juvenile Japanese flounder (3.0 g initial weight) and red sea bream (1.7 g initial weight) was estimated by feeding six semi-moist diets (45–48% crude protein on dry basis) containing graded levels of lysine hydrogen chloride in replacement of sodium glutamate. Most of the amino acids in the diets were provided by zein, fish meal and gelatin. In addition, free amino acids were added to ensure that the requirements for the essential amino acids, other than lysine, were met. Specific growth rate, feed efficiency, and nitrogen retention data were analyzed by non-linear regression using the broken-line model to obtain the lysine requirement estimates for Japanese flounder of 3.3, 4.2 and 4.6% of dietary protein, respectively, and 3.6, 4.3, and 4.4% of dietary protein for red sea bream. Estimates of the requirements for the other essential amino acids were made based on A/ E ratios of the whole-body amino acid profile.