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1.
We monitored feeding behavior and survival of starved juvenile olive flounder experimentally infected with the gill monogenean
Neoheterobothrium hirame. Infected flounder increased amount of the time spent in the water column by 117% when trying to capture live mysids, Neomysis sp. They also showed different feeding patterns from those of uninfected fish and made fewer attacks towards prey during
one feeding attempt. Although the average numbers of mysids captured by individuals were similar between infected and uninfected
fish, heavily infected fish tended to catch less prey. These results indicate that N. hirame reduces the feeding efficiency of the host for capturing live prey and possibly makes them more vulnerable to predation during
feeding. We could not detect any obvious difference in survival rates between uninfected, lightly and heavily infected fish
during 3 months of starvation. There was no evidence that starvation makes fish more susceptible to N. hirame. The present study provides first experimental evidence that N. hirame affects feeding behavior of juvenile olive flounder and supports the idea that this parasite indirectly reducing the host’s
survival and may be responsible for the recent reduction of the flounder population in Japan. 相似文献
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Jian-He Xu Feng You Wei Sun Bin-Lun Yan Pei-Jun Zhang Bi-Xiang Jing 《Aquaculture International》2008,16(6):623-634
Turbot Scophthalmus maximus exhibits sexually dimorphic growth, with females growing faster and reaching larger adult sizes than males. Thus, development
of techniques for preferentially producing females is necessary to optimize production of these species. In this paper, gynogenetic
diploids of turbot were induced by activating egg development with ultraviolet (UV)-irradiated left-eyed flounder Paralichthys olivaceus sperm combined with cold shock to prevent extrusion of the second polar body. The results of UV irradiation experiments showed
that survival, motility, and duration of activity of P. olivaceus sperm generally decreased with increase in UV dose. The typical Hertwig’s effect was observed after fertilized turbot eggs
with UV-irradiated P. olivaceus sperm and the optimal UV dose for gynogenetic haploid production was 36,000 erg mm−2. At 15°C, appropriate timing of cold shock for retention of the second polar body in turbot eggs was at 6 min after fertilization.
Results of different combinations of two shock temperatures (1 or 3°C) and four shock durations (15, 25, 35 or 45 min) at
6 min after fertilization demonstrated that shock of 25 min at 1°C gave the highest production of diploid gynogens (39.58%
relative to its diploid control). The results of this study reveal that the use of UV-irradiated P. olivaceus sperm for activation of turbot eggs and cold shock for polar body retention is an effective method to produce gynogenetic
offspring. 相似文献
3.
Tomomasa Matsuyama Chihaya Nakayasu Takamitsu Sakai Norihisa Oseko 《Fisheries Science》2009,75(2):335-341
Two monoclonal antibodies (MAbs: JFW1 and JFW10) were produced against peripheral blood leukocytes (PBL) in Japanese flounder.
Additionally, MAbs against flounder immunoglobulin (Ig; JFW20 and JFW21) were generated for the surface marker of Ig+ leukocytes using purified serum Ig as an antigen. MAb JFW1 recognized the surface marker of granulocytes and monocytes and
MAb JFW10 specifically bound to the surface antigen of thrombocytes. Flow cytometric analysis of PBL incubated with JFW1,
JFW10, JFW20 and JFW21 revealed that 2.5–7.4, 23.7–50.1, 25.2–26.1 and 5.2–8.3% of all leukocytes were positive for these
markers. Analysis of head kidney leukocytes (HKL) showed that JFW1, JFW10, JFW20 and JFW21 bound to 30.5–36.3, 1.9–2.8, 6.4–8.3
and 1.9–3.0% of all leukocytes, respectively. Western blot analysis after SDS-PAGE showed that JFW10 recognizes a protein
of 115 kDa from lysed PBL. JFW20 recognized the 70 and 74 kDa proteins of the heavy chain of Ig from serum. No band was observed
for either JFW1 or JFW21. These antibodies will be useful for the identification and isolation of Japanese flounder leukocyte
subpopulations and will facilitate immunological studies of flounder. 相似文献
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Kyoung Mi Won Mi Young Cho Myoung Ae Park Ki Hong Kim Soo Il Park Deok Chan Lee Mun Gyeong Kwon Jin Woo Kim 《Fisheries Science》2010,76(6):991-998
Pathological characteristics of olive flounder Paralichthys olivaceus experimentally infected with Streptococcus parauberis were studied. Various stressful conditions, aeration and netting stress in particular, led to induced mortality by S. parauberis. Netting stress-induced mortality was positively correlated to bacterial dose and stressful conditions. Inflammation of the
heart and pericarditis was the major pathological change observed in olive flounder experimentally infected with S. parauberis. During the infected period, the number of bacteria in the infected olive flounder was recorded over time. S. parauberis remained in all fish organs tested, especially in the heart and brain. 相似文献
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Shuang Jiao Zhihao Wu Xungang Tan Yulei Sui Lijuan Wang Feng You 《Fish physiology and biochemistry》2017,43(2):385-395
Although chromosome set manipulation techniques including polyploidy induction and gynogentic induction in flatfish are becoming increasingly mature, there exists a poor understanding of their effects on embryonic development. PAX3 plays crucial roles during embryonic myogenesis and neurogenesis. In olive flounder (Paralichthys olivaceus), there are two duplicated pax3 genes (pax3a, pax3b), and both of them are expressed in the brain and muscle regions with some subtle regional differences. We utilized pax3a and pax3b as indicators to preliminarily investigate whether chromosome set manipulation affects embryonic neurogenesis and myogenesis using whole-mount in situ hybridization. In the polyploid induction groups, 94 % of embryos in the triploid induction group had normal pax3a/3b expression patterns; however, 45 % of embryos in the tetraploid induction group showed abnormal pax3a/3b expression patterns from the tailbud formation stage to the hatching stage. Therefore, the artificial induction of triploidy and tetraploidy had a small or a moderate effect on flounder embryonic myogenesis and neurogenesis, respectively. In the gynogenetic induction groups, 87 % of embryos in the meiogynogenetic diploid induction group showed normal pax3a/3b expression patterns. However, almost 100 % of embryos in the gynogenetic haploid induction group and 63 % of embryos in the mitogynogenetic diploid induction group showed abnormal pax3a/3b expression patterns. Therefore, the induction of gynogenetic haploidy and mitogynogenetic diploidy had large effects on flounder embryonic myogenesis and neurogenesis. In conclusion, the differential expression of pax3a and pax3b may provide new insights for consideration of fish chromosome set manipulation. 相似文献
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Sung Hwoan Cho Sang-Mok Lee Byum Hee Park Sung-Choon Ji Jinhwan Lee Jeanhee Bae Sung-Yong Oh 《Fish physiology and biochemistry》2007,33(1):49-57
This study was performed to determine the effect of the dietary inclusion of various sources of green tea on growth, body
composition and blood chemistry of the olive flounder. Twenty-five juvenile fish were distributed into each of 15 180 l flow-through
tanks. Five experimental diets with triplicates were prepared: control, raw leaves, dry leaves, by-product and extract. The
5% various sources (raw leaves, dry leaves and by-product) of green tea were included in the experimental diets at the expense
of 5% wheat flour. The extract was diluted with water and mixed with the ingredients to maintain 5% green tea at the same
concentration as in the other diets. Weight gain and specific growth rate of fish fed the control diet and experimental diet
containing extract were higher than those of fish fed the diets containing raw and dry leaves and by-product. Feed and protein
efficiency ratio for fish fed the control diet and diet containing extract was higher than for fish fed the diets containing
raw leaves and by-product. The level of low-density lipoprotein (LDL) cholesterol of fish fed the control diet was higher
than that of fish fed the other diets containing various sources of green tea. The glutamic oxaloacetic transaminase (GPT)
concentration of fish fed the diets containing raw leaves and extract was lower than that of fish fed the control diet. Crude
lipid content of liver in fish fed the control diet was higher than that in fish fed the diets containing raw and dry leaves
and by-product but was not significantly different from that of fish fed the diet containing extract. Dietary inclusion of
extract was the most effective way to improve growth and feed utilization of the olive flounder among the various sources
of green tea, and all sources of green tea were effective in lowering serum LDL cholesterol and GPT of the fish. 相似文献
11.
Wei Liu Huayu Song Aoyun Li Xinxin Du Yuezhong Liu Yan He Quanqi Zhang Jie Qi 《Fish physiology and biochemistry》2016,42(5):1275-1285
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Feng He Hai Shen Wen Shuang Lin Dong Bao Shi Cai Fang Chen Lian Shun Wang Jun Yao Xing Jiang Mu Yu Guo Zhou 《Fish physiology and biochemistry》2009,35(3):333-340
Cytochrome P450 aromatase, which is encoded by the CYP19a gene, converts androgens to estradiol. Considerable evidence suggests that estrogens play an important role in fish reproductive
process. Therefore CYP19a is an excellent candidate gene for reproductive traits. Variants in the promoter of the CYP19a gene might also be involved in the control of aromatase expression and affect regulatory mechanism linking cholesterol metabolism
to the synthesis of sex steroids. In this study, nine single-nucleotide polymorphisms (SNPs) were detected with polymerase
chain reaction-single stranded conformational polymorphism (PCR-SSCP), namely A-680G, G-672A, AGTAGT-649 inserting or deleting,
T-623C, C-410A, T7-454A, T-402C, TTTCCAGACTGA-345 inserting or deleting, and G-297C. Nine SNPs within the promoter of the
CYP19a gene were tested for association with four reproductive traits [serum testosterone (T), serum 17β-estradiol (E2), hepatosomatic index (HSI), and gonadosomatic index (GSI)] in a population of 50 female Japanese flounder individuals. A
locus, P3 (TTTCCAGACTGA-345 inserting or deleting, G-297C), was significantly associated with 17β-estradiol (E2) level (P < 0.05) in female Japanese flounder. In addition, there was significant association between one diplotype based on nine SNPs
and reproductive trait. The genetic effect for E2 level of diplotype D3 was significantly higher than those of other diplotypes (P < 0.05). Results indicate that these genetic effects of those variants on E2 level may help to explain CYP19a gene status in the reproductive endocrinology of Japanese flounder. 相似文献
13.
Thyroid hormone deficiency in abnormal larvae of the Japanese flounder <Emphasis Type="Italic">Paralichthys olivaceus</Emphasis> 总被引:1,自引:0,他引:1
ABSTRACT: In large-scale rearing of juveniles of the Japanese flounder Paralichthys olivaceus, a certain morphological abnormality occurred spontaneously in 4% of the fish. These fish showed a slight but clearly different appearance from any developmental stage of this species, and did not settle when all the other juveniles in the same tank completed metamorphosis and had settled. From comparisons of external and internal structures between the normal and the abnormal fish, the abnormality was attributed to unbalanced progress of metamorphosis, mainly due to metamorphic stasis. The thyroid of the abnormal fish was apparently activated morphologically. In addition, serum thyroxine (T4) concentrations in the abnormal fish were reduced to less than 1/10 of that of normal fish. After 14 days of T4 treatment (0.1 p.p.m) of the abnormal fish, all the abnormal characteristics disappeared, and the fish recovered to normal, suggesting normal responsiveness to thyroid hormones in peripheral tissues, whereas thiourea treatment (30 p.p.m., 14 days) further delayed metamorphosis. These results suggest that these abnormal fish were suffering from thyroid hormone deficiency, and were unable to secrete a sufficient amount of thyroid hormone to complete metamorphosis. 相似文献
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Kuniaki Nakata Ikki Yamamoto Yoshifumi Miyama Toru Nakamaru Reiji Masuda Masatomo Tagawa 《Fisheries Science》2017,83(6):1027-1035
In the aquaculture of the Japanese flounder Paralichthys olivaceus, hypermelanosis, a malpigmentation condition in which the scales of a significant area on the blind side express the characteristics of those on the ocular side, remains a major concern. Since introducing sand into the rearing tank effectively suppresses hypermelanosis, the inhibitory effects of various characteristics of the surface of the tank floor were investigated. Although an inhibitory effect was observed in both tanks with a sand-image floor and a sand-pasted floor, the strongest effect was found in tanks with a dimpled floor. In addition, covering the inner surface of the tank with net also inhibited hypermelanosis. Using a commercially available corrugated plate, the inhibition of hypermelanosis was confirmed with a noted increase in this effect when combined with light coloration. Juveniles tended to situate themselves in the valley portions of the corrugated plate, suggesting that floor contact with the blind side may contribute to hypermelanosis inhibition. Further observations on the floor contact area with various floor configurations suggested that hypermelanosis is locally suppressed in the areas with floor contact. Therefore, suppression by an undulated (both dimpled and corrugated) floor is likely due to an increase in floor contact area with the blind side. 相似文献
18.
There is a need to develop low-cost methods for larviculture that emphasize disease prevention. We evaluated stagnant water
larviculture in flounder Paralichthys olivaceus using rotifer amictic eggs treated with glutaraldehyde. Growth and survival of the larvae were similar to in larvae reared
by standard running water larviculture with daily feeding of rotifers (control). In the experimental group, the n-3 highly
unsaturated fatty acid content of rotifers in the rearing water was higher than in the enriched rotifers fed to the control
group. We also observed a similar pattern for the fatty acid composition of flounder larvae. The viable bacterial counts associated
with rotifers in stagnant water were lower than those associated with enriched rotifers, and there were fewer bacterial genera.
However, the viable bacterial count was the same or higher in the experimental rearing water compared with that in the control
group. The α-Proteobacteria and Cytophaga–Flavobacterium–Bacteroidetes group dominated the bacterial community structure after larval hatching. To our knowledge, this is the first time that stagnant
water larviculture, using only disinfected amictic eggs, has been successfully demonstrated on a mass production scale. This
method appears to offer benefits including improved nutrition, more favorable bacterial communities, and lower cost. 相似文献
19.
We evaluated the effects of diets incorporating the red algae Pyropia yezoensis, prepared by several different extraction methods, on the growth of juvenile Japanese flounder Paralichthys olivaceus. We assessed growth performance, as well as the levels of amino acids, fatty acids, insulin-like growth factor I (IGF-I) and interleukins (ILs). Four experimental diets were developed based on different methods of processing P. yezoensis. A commercial feed, laver powder (P), high-pressure heat extraction of laver (HPHE) and acid hydrolysis extraction of laver were used as the experimental diets. Three experimental replicates were established for each diet (40 fish/group, body weight 123.7 ± 1.1 g), and the fish were fed for 6 weeks. We found no significant differences in weight gain, specific growth rate or feeding efficiency among the groups (P > 0.05); however, the fish fed HPHE had the greatest growth performance. Fish fed the laver extracts exhibited the highest protein efficiency ratio compared with the control and P groups. The experimental groups fed P. yezoensis extracts had significantly higher levels of IGF-I (P < 0.05) than those of the control group. High levels of IL-2 were found in the P and HPHE groups, IL-12 in the HPHE group, and IL-6 in all experimental groups. Therefore, these results suggest that a P. yezoensis extract improved the growth performance and immunity of Japanese flounder. In particular, the high-pressure heating process was a useful extraction method for preparing a P. yezoensis extract, which had beneficial effects as a dietary supplement in Japanese flounder. 相似文献
20.
Viliame Waqalevu Akinobu Honda Hideaki Matsui Kazuhiro Shiozaki Tomonari Kotani 《Fisheries Science》2018,84(6):1037-1049
Two common live feeds, the Brachionus plicatilis species complex SS-type and L-type were used to assess whether there were any differences in protein hydrolysis and digestive trypsin activity in first feeding Japanese flounder. There were no significant differences in hydrolysis activity at 2, 3 and 7 days after hatching (DAH). At 5 DAH, hydrolysis activity was significantly higher in larvae fed SS-type (p?<?0.05) at 50 kDa in 1.5- and 3-h incubation whereas L-type treatment had not completely hydrolyzed the proteins after 3 h at the same molecular weight. Larvae fed SS-type had significantly higher (p?<?0.05) trypsin activity at 3, 5, 6, 7 DAH. Contribution of live prey to trypsin fraction in larvae showed significantly higher (p?<?0.05) fraction for SS-type at 5 DAH (2.18?±?0.44%) and 6 DAH (2.04?±?0.29%) and the effect of exogenous trypsin from live prey was relatively low when compared to the total trypsin activity in larvae. This study discusses the differences in ability to digest proteins in Japanese flounder when fed different rotifer morphotypes and highlights the adaptability of this species to alternative rotifer morphotypes during its early developmental stages. 相似文献