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Japanese Flounder (japanese + flounder)
Selected AbstractsNeuromast formation in the prehatching embryos of the Japanese flounder (Paralichthys olivaceus)ACTA ZOOLOGICA, Issue 2 2003Machiko Otsuka Abstract The present paper clarifies the initial development of the lateral line organs in the embryonic Japanese flounder, Paralichthys olivaceus. The first appearances of lateral line primordia, and the proliferation, distribution and morphological development of the free neuromasts, including nerve ending formation: establishment of hair cell innervations via the formation of synapses, were examined by light microscopy, scanning and transmission electron microscopy. The first pair of neuromast primordia appeared in the otic region , 30 h prior to hatching and subsequently differentiated into free neuromasts, otic neuromasts, after , 8 h. At hatching, a pair of free neuromasts and three pairs of neuromast primordia were present on the head, and three pairs of neuromast primordia were present on the trunk. The hair cell polarity of the otic neuromast until just prior to hatching was radial, but not bi-directional. The typical afferent and efferent nerve endings in the otic neuromasts had formed by the time of hatching, suggesting that the otic neuromasts are functional prior to hatching. The three neuromast primordia located on each side of the trunk were derived from a long, narrow ectodermal cell cluster and erupted through the epidermis after hatching. [source] Acute CO2 tolerance during the early developmental stages of four marine teleostsENVIRONMENTAL TOXICOLOGY, Issue 6 2003T. Kikkawa Abstract Ocean sequestration of CO2 is proposed as a possible measure to mitigate climate changes caused by increasing atmospheric concentrations of the gas, but its impact on the marine ecosystem is unknown. We investigated the acute lethal effect of CO2 during the early developmental stages of four marine teleosts: red sea bream (Pagrus major), Japanese whiting (Sillago japonica), Japanese flounder (Paralichthys olivaceus), and eastern little tuna (Euthynnus affinis). The percentages of larvae that hatched and survived were not affected by exposure to water with a PCO2 of 1.0 kPa (= 7.5 mmHg) within 24 h. Median lethal PCO2 values for a 360-min exposure were 1.4 kPa (cleavage), 5.1 kPa (embryo), 7.3 kPa (preflexion), 4.2 kPa (flexion), 4.6 kPa (postflexion), and 2.5 kPa (juvenile) for red sea bream; 2.4 kPa (cleavage), 4.9 kPa (embryo), 5.9 kPa (preflexion), 6.1 kPa (flexion), 4.1 kPa (postflexion), and 2.7 kPa (juvenile) for Japanese whiting; 2.8 kPa (cleavage) and > 7.0 kPa (young) for Japanese flounder; and 11.8 kPa (cleavage) for eastern little tuna. Red sea bream and Japanese whiting of all ontogenetic stages had similar susceptibilities to CO2: the most susceptible stages were cleavage and juvenile, whereas the most tolerant stages were preflexion and flexion. © 2003 Wiley Periodicals, Inc. Environ Toxicol 18: 375,382, 2003 [source] Developmental change in RNA: DNA ratios of fed and starved laboratory-reared Japanese flounder larvae and juveniles, and its application to assessment of nutritional condition for wild fishJOURNAL OF FISH BIOLOGY, Issue 4 2001W. S. Gwak Starved Japanese flounder Paralichthys olivaceus larvae were characterized by relatively lower levels of RNA content throughout their early life stages. Significant differences in the RNA: DNA ratios were found between fed and starved fish, and appeared to increase as starvation proceeded. Ontogenetic changes in RNA: DNA ratios were clearly observed during metamorphosis, especially decreasing during the period from the late-metamorphic to postmetamorphic stages. The criteria established from these laboratory experiments, were applied to the nutritional condition of wild larvae and juveniles collected in Wakasa Bay, Sea of Japan in 1994 and 1995 by measuring RNA and DNA content. Starved fish were mainly found in stage I (settling stage) fish during the late season of settlement in 1995. This suggests that starvation could be associated with settlement in Japanese flounder. [source] Reevaluation of the Dietary Protein Requirement of Japanese Flounder Paralichthys olivaceusJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2003Kangwoong Kim An experiment was conducted to determine the dietary protein requirement by different analysis methods and to study the effects of dietary protein levels on growth performance and body composition in Japanese flounder Paralichthys olivaceus fed white fish meal and casein-based diets for 8 wk. After a 1-wk conditioning period, one of six isocaloric diets containing 30, 36, 42, 48, 54, and 60% crude protein (CP) was fed to fish at approximately 4,5% of wet body weight on a dry matter basis to triplicate groups of 15 fish averaging 13.3 ± 0.06 g (mean ± SD). After 8 wk of the feeding trial, weight gain (WG) and feed efficiency (FE) from fish fed 48% CP diet were similar to those from fish fed 42% and 54% CP diets, and were significantly higher than those from fish fed 30, 36 and 60% CP diets (P < 0.05). Fish fed 48 and 54% CP diets had a significant higher specific growth rate (SGR) than did fish fed 30 and 36% CP diets (P 0.05). Protein efficiency ratio (PER) was inversely related to the dietary protein level. No significant differences existed in hematocrit (PCV) and survival rate among the dietary treatments. Broken-line model analysis indicated that the optimum dietary protein level could be 44.0 ± 3.0% for maximum WG in Japanese flounder. Polynomial regression analysis of the dose-response showed that maximum WG occurred at 50.2% (R2= 0.94) based on WG, and the second-order polynomial regression analysis with 95% confidence limits revealed that the range of minimum protein requirement was between 38.9% and 40.3% based on WG. Therefore, these findings suggest that the optimum dietary protein requirement for maximum growth of Japanese flounder is greater than 40%, but less than 44% CP in the fish meal and casein-based diets containing 17.0 kJ/g of energy. [source] Effects of Dietary Chlorella ellipsoidea Supplementation on Growth, Blood Characteristics, and Whole-Body Composition in Juvenile Japanese Flounder Paralichthys olivaceusJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2002Kang-Woong Kim The study was conducted to investigate the effects of dietary Chlorella powder (C) supplementation on growth performance, blood characteristics, and whole-body composition in juvenile Japanese flounder Paralichthys olivaceus. Four experimental diets were supplemented with C at 0, 1, 2 and 4% (C0, C1, C2, and C4) on a dry-weight basis. Three replicate groups of fish averaging 1.13 ± 0.02 g (Mean ± SD) were randomly distributed in each aquarium and fed one of four experimental diets for 12 wk. After 12 wk of the feeding trial, fish fed C2 diet had higher weight gain (WG), feed efficiency (FE), and protein efficiency ratio (PER) than did fish fed C0 and C1 diets (P 0.05); however, there was no significant difference among fish fed C1 and C4 diets, and among fish fed C2 and C4 diets (P > 0.05). Fish fed C2 and C4 diets had a lower serum cholesterol level than did fish fed C0 and C1 diets (P 0.05). Fish fed C2 and C4 diets had a lower body fat than did fish fed C0 (P 0.05). These results indicate that dietary supplementation of 2%Chlorella powder in the commercial diets could improve growth, feed utilization, serum cholesterol level, and whole-body fat contents in juvenile Japanese flounder. [source] Pharmacokinetics of Dietary 13C-labeled Icosapentaenoic Acid in Japanese Flounder Paralichthys olivaceusJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2002Akio Tago The objectives of this study were to investigate: 1) the pharmacokinetics of dietary icosapentaenoic acid (EPA) in the plasma using 13C-labeled EPA ([13C]EPA); 2) the bioavailability of [13C]EPA with different chemical forms; and 3) an effective plasma EPA level for normal growth of the Japanese flounder Parachthys olivaceus. [13C]EPA was biosynthesized using the Chlorella Nannochloropsis oculate, and 1-myristoyl 2-[13C]icosapentaenoyl phasphatidyl-choline ([13C]EPA-PC) and [13C]EPA ethyl ester ([13C]EPA-EE) were chemically synthesized from [13C]EPA. Free [13C]EPA ([13C]EPA-FREE) dissolved in 0.5% tragacanth gum-polye-thyleneglycol (3:1, V/V) was administered to the Japanese flounder at dosages of 2.8, 5.6, and 16.8 mg/kg by a single oral administration. [13C]EPA-PC (44.8 mg/kg) and [13C]EPA-EE (18.3 mg/kg), equimolar to 3.0 mg [13C]EPA-FREE (16.8 mg/kg), were administered to the fish in a similar manner. In [13C]EPA-FREE dosed fish, the kinetics of the mean plasma [13C]EPA were linear with respect to dose. [13C]EPA-FREE and [13C]EPA-PC were more efecient in maintaining high plasma EPA levels than [13C]EPA-EE in the Japanese flounder. [13C]EPA was distributed in plasma, blood cell, eyeball containing the orbital fat, liver, stomach, intestine, skin, brain, heart and muscle in three [13C]EPA derivatives studies. The effective plasma EPA level for normal growth of the Japanese flounder is estimated to be 307 to 937 ,g/mL for EPA-FREE administration, and from 286 to 815 ,g/mL 6.3 to 38 mg/mL for the EPA-PC administration. [source] Interactive effects of dietary cholesterol and protein sources on growth performance and cholesterol metabolism of Japanese flounder (Paralichthys olivaceus)AQUACULTURE NUTRITION, Issue 4 2010J. DENG Abstract A feeding trial was conducted to compare the effects of supplemental cholesterol in fish meal (FM), fish protein concentrate (FPC), soy protein isolate (SPI) and soy protein concentrate (SPC)-based diets on growth performance and plasma lipoprotein levels of Japanese flounder (Paralichthys olivaceus). Eight isonitrogenous and isocaloric diets including FM, FPC, SPI or SPC as sole protein source with or without supplementation with 10 g cholesterol kg,1 diet were fed to juvenile fish for 8 weeks. Dietary cholesterol supplementation significantly increased the feed intake and specific growth rate in fish fed SPI-based diets, but decreased those in fish fed FPC-based diets. In addition, cholesterol supplementation significantly increased the level of cholesterol and ratio of low-density lipoprotein cholesterol to high-density lipoprotein cholesterol in plasma of fish fed fish protein-based diets, whereas no effects were observed in fish fed soy protein-based diets. The hepatic lipid content of fish fed FPC-, SPI- or SPC-based diets were significantly increased by supplemental cholesterol, but no influence was observed in fish fed FM-based diets. These results suggested that dietary protein source modify the growth-stimulating action of cholesterol; cholesterol supplementation may increase the arteriosclerotic lesion in fish fed fish protein-based diets and the incidence of fatty liver in fish fed soy protein-based diets. [source] Dietary vitamin A requirements of juvenile Japanese flounder Paralichthys olivaceusAQUACULTURE NUTRITION, Issue 1 2005L.H.H. HERNANDEZ Abstract A 70-day feeding experiment was conducted to assess the dietary vitamin A (VA) requirements of juvenile Japanese flounder (Paralichthys olivaceus). Six semi-purified diets with VA supplementations of 0, 5000, 10 000, 15 000, 20 000 and 25 000 IU kg,1 were fed twice a day to triplicate groups of 20 juveniles per tank with an initial weight of 1.59 ± 0.01 g (mean ± SE). Weight gain (WG) and specific growth rate (SGR) increased as dietary VA increased up to 10 000 IU kg,1. Significantly lower WG and SGR were observed for the 0 IU kg,1 treatment than for treatments of 5000, 10 000 and 15 000 IU kg,1. Highest WG and SGR were observed in fish fed 10 000 IU kg,1; slightly lower values were recorded in fish fed 15 000, 20 000 or 25 000 IU kg1. No significant difference was observed in survival rate among treatments. Whole body total lipid was significantly higher in fish fed 0 and 5000 IU kg,1 than for other levels. Reduced growth and small livers were observed as signs of VA deficiency in fish fed 0 IU kg,1. Slightly reduced growth and pale fragile livers were observed as effects of VA excess in fish fed 25 000 IU kg,1. Total retinol contents in liver and eyes increased with increasing levels of dietary VA. No retinol was detected in livers, and significantly lower total retinol content was observed in eyes, of fish fed 0 IU kg,1. WG analysed by the broken line method indicated that an optimum dietary VA requirement of 9000 IU kg,1. [source] Immune response of DNA vaccine against lymphocystis disease virus and expression analysis of immune-related genes after vaccinationAQUACULTURE RESEARCH, Issue 10 2010Feng Rong Zheng Abstract In this study, we found that an intramuscular injection of Japanese flounder (Paralichthys olivaceus, 60,80 g in weight and 15,20 mL in length) with 5 ,g of a DNA vaccine (pEGFP-N2-LCDV-cn-MCP 0.6 kb, containing lymphocystis disease virus major capsid protein gene) induced a strong immune response. Subsequent real-time polymerase chain reaction showed that the expression of immune-related genes [e.g., major histocompatibility complex (MHC) class I ,, MHC II ,, T-cell receptor (TCR), tumour necrosis factor (TNF), tumour necrosis factor receptor (TNFR), Mx, interleukin (IL)-1,, CXC and IL-8R] was significantly changed after DNA vaccination. The most remarkable alternation was the expression of MHC I , and MHC II , genes: MHC II , reached the maximum on day 8 in different tissues, and MHC I , on day 2 in the intestine and gills. The expression of TCR increased and reached a plateau in 2 days in the spleen, gills, kidney and liver after vaccination and then decreased after day 8. In contrast, the expression of TCR in the intestine increased and reached a plateau in 8 days. The expression of IL-8R reached the maximum on day 2 in different tissues and then decreased on day 8. Mx increased in the gills, kidney, spleen and liver on days 2, 8, 2 and 2, but decreased in the intestine, gills, spleen and liver on days 2, 8, 8 and 8 respectively. The TNFR expression increased in the spleen, kidney and gills on days 2, 8 and 8, but decreased in intestine, liver and gills on days 2, 8 and 8 respectively. The expression of TNF, CXC and IL-1, increased 2 and 8 days after the injection of DNA vaccine. However, the expression of TNF, CXC and IL-1, altered on days 2 and 8 with different patterns in different tissues respectively. The fish responded to the DNA vaccine by yielding a specific immunoglobulin against lymphocystis disease virus (LCDV) as observed with indirect ELISA. The DNA vaccine induced a unique humoral response, suggesting that the DNA vaccine activated both cellular and humoral defences of the specific immune system of Japanese flounder. [source] Alternative protein sources in diets for Japanese flounder Paralichthys olivaceus (Temminck and Schlegel): II.AQUACULTURE RESEARCH, Issue 6 2010Effects on nutrient digestibility, digestive enzyme activity Abstract An 8-week feeding trial was conducted to compare the effects of dietary protein sources on nutrient digestibility and digestive enzyme activity. Four experimental diets were formulated to contain one of the following as the sole protein source: fish meal (FM), fish protein concentrate (FPC), soy protein concentrate (SPC) and soy protein isolate (SPI). Each diet was randomly assigned to triplicate aquaria stocked with 25 Japanese flounder (Paralichthys olivaceus) each. The dry matter, crude protein and energy digestibility and individual amino acid availability of the SPC-based diet were significantly lower than those of the other diets. The crude lipid digestibility of soy protein-based diets was significantly lower than that of the FM-based diet. The pepsin/protease activity was significantly higher in fish fed fish protein-based diets compared with fish fed soy protein-based diets. The lipase activity in fish fed the SPI-based diet was the highest among the dietary treatments. These results indicate that P. olivaceus can effectively digest the protein from FPC and SPI (but not SPC) as well as FM. The low protein digestibility and amino acid availability of the SPC-based diet may be related to the non-protein compounds present in SPC, whereas the low-lipid digestibility of soy protein-based diets may contribute to the undigested soy protein fractions and/or the alcohol-soluble components. [source] Quantitative genetic parameters for growth-related and morphometric traits of hatchery-produced Japanese flounder Paralichthys olivaceus in the wildAQUACULTURE RESEARCH, Issue 12 2007Takahito Shikano Abstract To understand quantitative genetic characteristics of hatchery-produced Japanese flounder in the wild, heritability and genetic correlation of growth-related and morphometric traits were examined in yearling released individuals at a coastal region in northeast Japan. Quantitative genetic parameters were estimated with restricted maximum likelihood following reconstruction of pedigree by a likelihood method using seven microsatellite loci. Estimates of heritability were 0.65 and 0.51 for growth-related traits (body length and the proportion of body length to body depth) and 0.45,0.62 for morphometric traits (vertebral count and dorsal and anal fin ray counts). Genetic correlation was significantly positive (0.61) between dorsal and anal fin ray counts, indicating the possibility of pleiotropic genes or gametic phase disequilibrium for these traits. All the estimates of heritability and genetic correlation in the released individuals were close to those of hatchery-reared juveniles, suggesting that yearling released individuals had similar quantitative genetic characteristics of growth and morphometric traits in the wild to hatchery-reared juveniles. [source] Occurrence of Listonella anguillarum in seed production environments of Japanese flounder Paralichthys olivaceus (Temminck et Schlegel)AQUACULTURE RESEARCH, Issue 9 2005Haruo Sugita Abstract The present study was undertaken to investigate the distribution of Listonella anguillarum in the rearing water, fish and diets (rotifers) of Japanese flounder (Paralichthys olivaceus). A total of 793 isolates were obtained from the seed production environment of Japanese flounder and 175 out of them were identified as L. anguillarum by biochemical characterization, polymerase chain reaction (PCR) detection for VAH1 haemolysin gene and phylogenetic analysis of 16S ribosomal deoxyribonucleic acids (rDNA) sequences. These results strongly suggested that L. anguillarum is rapidly and accurately identified by the combination of incubation on thiosulphate,citrate,bile salt,sucrose agar at 35°C overnight and PCR detection for the VAH1 haemolysin gene. All flounder specimens and all rotifer samples harboured L. anguillarum at high densities of 6.9 × 103,6.3 × 105 colony forming units (CFU) g,1 and 1.5 × 104,2.3 × 106 CFU g,1, respectively, while as low as 5.0 × 100,2.0 × 101 CFU mL,1 of L. aguillarum were detected in only two of 11 seawater samples, even though no vibriosis occurred in larval and juvenile flounder of tanks. This fact strongly suggests that L. anguillarum is an inhabitant in the seed production environments of Japanese flounder. [source] | ||||||||||