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1.
The biological cleaning agent Pondplus was dowsed each ten days at different dosage into breeding ponds for Chinese mitten crab with stocking rate at 12 000 ind./ha, to evaluate its purification effects on water environment in breeding ponds and its effects on Chinese mitten crab growth. The results showed that dousing treatment improved the water quality significantly as evaluated according to the parameters of DO, CODMn, NH4 + - N and NO2 - -N. Particularly, when the air temperature was higher than 35℃, the diurnal observation on DO values at the bottom of ponds showed that dousing at 450 g/( ha•m) gave a DO value higher than 4 mg/L all day long, which was 2 mg/L higher than that of control. The observed increase of Chinese mitten crab were 14. 9% , 27.8% , 27.8% by average weight, when dousing at 150, 300, 450 g/(ha • m) , respectively. Accordingly, the production increased by 8.5%, 11.9%, 18.6% through its promotion of Chinese mitten crab growth, and the economic efficiency were enhanced by 96.2% , 159.8% , 180.9%.  相似文献   

2.
细角螺的繁殖生态条件及繁殖习性   总被引:1,自引:0,他引:1  
许章程 《水产学报》2006,30(6):848-851
Hemifusus ternatanus(Gmelin), a gastropoda living in the deep water areas of undertide,as well as a delicious seafood, was distributed mainly in Chinese southeast seas and Japanese seas near the coast. In this experiment Hemifusus ternatanus' breeding ecological conditions and its propagation habit were studied in order to provide an experimental foundation for the artificial breeding. The brood stocks of test animals collected from the waters in Taiwan Strait, and then were examinated their growing temperature, salinity, feeding and propagation habit in the laboratory. The re sults showed that the growing temperature for Hemifusus ternatanus ranges from 16 ℃ to 32 ℃, with an optimum temperature between 20 ℃ to 28 ℃ and between 23 ℃ and 28 ℃ for breeding. The optimum growth salinity was 18.3-32.3 though it much adapts to salinity from 13 to 35. They prefer to feed on bivalves particularly those with thin shells and byssusless. Hemifusus ternatanus is dioecious and fertilization finishes inside the body. It was called as egg vesicle procreation that the whole stages of embryo growth were developed within egg vesicle. Larva forms as soon as it leaves egg vesicle, which is called direct occurrence type. The larva became the juvenile after metamorphosis during 20-25 days development. It was first to obtained 233 juveniles with shell height 32-45 mm by an artificial breeding method.  相似文献   

3.
凌去非 《水产学报》2005,29(1):120-123
Gynogenesis is thought to be a useful method to generate fully inbred line and to initiate monosex culture in teleost fish. This article presents results of a study of gynogenesis of tench, Tinca tinca L. from Eltrix River of Xinjiang, China, induced by the common carp ( Cyprinus carpio ) sperm inactivated with UV irradiation. When cold shocking method was used to prevent exmasion of the second polar body in order to produce gynogenetic diploids, the optimum treated parameters were screened as cold shocking for 20min at 4℃, 5min after insemination. On this condition, 10.23% of the treated eggs survived at feeding stage. A comparative study between the gynogenesis and their parents was made by RAPD technique. 82 random primers of 10 nucleotide long sequence were used in RAPD analysis. The results showed that each primer gives 3- 12 fragments for each sample with the fragment length 330 - 2 460 bp, and the genetic similarity between gynogenesis and their mother was 97.4 %, while the genetic similarity between gynogenesis and their father was 27.4%, and there were no bands only shared by gynogenesis and their father, the common carp. It revealed that the chromosome of their father, the common carp, did not penetrate into the construction of gynogenetic tench.  相似文献   

4.
大菱鲆胚胎的玻璃化冷冻保存   总被引:3,自引:0,他引:3  
田永胜 《水产学报》2005,29(2):275-280
Vitrification solutions were examined for their suitability of cryopreservation of turbot (Seophthulnms maximus) embryos. PMPI gave higher survival rate (75.68%) than other vitrification solutions and was considered to be suitable liar the cryopreservation of turbot embryos. The freezing point of the vitrification solutions consisted of PG and MeOH in the proportion of 3:2 was measured when the vitrification solutions were cryopreserved. It showed that the vitrification solutions with a cryoprotectant concentration of over 41% have no freezing point and the freezing points of vitrification solutions containing 33.33%-40% cryprotectants were between -32.4℃ and -65.4℃, The freezing point decreased with the increase of cryoprotectant concentration. The resistance of turbot embryos at different stages to the cryoprotectants was studied, It was found that the turbot embryos from 4-5 pairs somite to tail bud were more resistant to cryoprotectants and suitable to vitrify. A live embryo was obtained after cryopreservation in liquid nitrogen for 14h and was hatched out。  相似文献   

5.
Four primary zooplankton species in Taolinkou reservoir located at Qinglong fiver in Qinglong Manchu county in Hebei province were investigated from April 2007 to March 2008, and the zooplankton species and anniversary distribution were concluded. The results showed that in the investigating period 57 kinds of zooplankton were totally found with protozoa 16, rotifera 22, cladocera 12 and copepoda 7, the forms and the preponderant species were different in different months. The average quantity of zooplankton in each month was 185.90 ind./L. The maximum quantity appeared at the earlier autumn. The average quantity (513.60 ind./L) of all sampling stations raised to its peak in August. The quantity was increasing with the temperature in spring and summer, decreasing after September, and lowest in winter. The average biomass was 1.68 mg/L which was the same diversification as the average quantity.  相似文献   

6.
赤点石斑鱼神经坏死病毒外壳蛋白全基因克隆与序列分析   总被引:5,自引:1,他引:5  
黄剑南 《水产学报》2005,29(3):429-432
  相似文献   

7.
6种常用渔药对厚颌鲂鱼苗的急性毒性试验   总被引:3,自引:0,他引:3       下载免费PDF全文
The acute toxicity of the mixture of copper sulphate and ferrous sulphate (ratio 5: 2), potassium permanganate ( KMnO4 ) , trichlorphon ( C4H8O4 C13P) , strong-chloride, bromochloropropene and formalin towards Larva of Megalobrama pellegrini was studied at by biological toxic test method at the water temperature of 29℃ to 30℃. The results showed that the median-lethal concentrations of 48h were 5.78,6.50,4.90,2.55,0. 042,120 mg/L, respectively; the safe concentrations were 0. 445,0. 528 、0. 268,0. 190,0. 003,7. 500mg/L, respectively. The larva of Megalobrama pellegrini is more sensitive than other fish, bromochloropropene can't be used. The drug dosage and time should be based on the specific situation circumstances in production.  相似文献   

8.
<正>The Journal of Resources and Ecology(JRE)is an international English language journal that was started in 2010.The journal is jointly sponsored by the Institute of Geographic Sciences andNatural Resources Research(IGSNRR).Chinese Academy of Sciences(CAS).the China Society of Natural Resources,and lhe Ecological Society of China.The Journal of Resources and Ecology's mission is to create a platform for the promotion of international academic exchange.The journal aims to provide a comprehensive representation of  相似文献   

9.
In an attempt to understand growth regulation in the Japanese eel, Anguilla japonica, we cloned insulin-like growth factor-I (IGF-I) cDNAs and examined their mRNA expression in several tissues. Two eel IGF-I (eIGF-I) cDNAs encoding preprohormones, eIGF-I-Ea1and eIGF-I-Ea2, were cloned from the liver by polymerase chain reaction (PCR). The preproIGF-Is were identical in signal peptide and mature IGF-I, but different in the E domain—eIGF-I-Ea2 mRNA was 36 bp longer than eIGF-I-Ea1 mRNA. Eel IGF-I was 83–94% identical with that of teleosts, 71% identical with that of dogfish, 87% identical with that of bullfrog and chicken, and 83% identical with that of humans. In both males and females the highest eIGF-I-Ea1 mRNA levels were observed in the liver, with detectable levels also found in the gills, heart, stomach, spleen, kidney, intestine, swim-bladder, muscle, and gonads. eIGF-I-Ea1 mRNA levels in the liver were higher in females than in males whereas in the intestine they were lower than in males. eIGF-I-Ea2 mRNA was detected in all the tissues examined and at similar levels in males and females. In this experiment higher eIGF-I-Ea1 mRNA levels were observed in the liver of larger glass eels than in those of smaller fish. eIGF-I-Ea2 mRNA levels were also higher in larger eels, although they were lower than IGF-I-Ea1 mRNA levels. Both eIGF-I mRNA levels in liver were positively correlated with the body size of the␣glass eels. Intraperitoneal injection of recombinant eel GH (reGH), 0.25 μg g−1 body weight, into glass eels resulted in a significant increase in both eIGF-I mRNAs in the liver 1 day after injection compared with control fish, but no elevation was observed 2 days after injection. Incubation of liver slices with reGH at concentrations of 10, 100, and 1,000 ng mL−1 for 24 h resulted in a significant concentration-dependent increase in the levels of both eIGF-I mRNAs. Higher levels of eIGF-I-Ea1 and Ea2 mRNA were observed in the gills ofseawater-reared eels than in those of freshwater-reared fish, but no differenceswere observed in the whole kidney. These results suggest that IGF-I is involved in the regulation of somatic growth and also in adaptation of the Japanese eel to seawater.  相似文献   

10.
The aim of the present study was to determine the effect of starvation on digestive enzymes activity of the carp (Cyprinus carpio) at the water temperature 18 -20℃ in the cycle and flow water aquarium. The experiment was designed for four groups with three replication,which were 0 day(control) , 10 days, 20 days, 30days group. The results showed That there was a trend to drop first and keep stabilization for Cyprinus carpio body weight and Meat Content with the prolongatin of starvation, and that Effect of starvation stress on the the activity of protease in intestine and hepatopancreas of Cyprinus carpio was significant, with the prolongatin of starvation, there was a trend to increase then drop for the activity of protease in fore-gut, mid-gut hind-gut and hepatopancreas of Cyprinus carpio. And that the variatin for activityof amylase in fore-gut was significant butthat of the others was no significant.  相似文献   

11.
The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna.  相似文献   

12.
Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg?1 protein) than essential amino acids (425.82 ± 9.15 g kg?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting.  相似文献   

13.
In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg.  相似文献   

14.
在基础饲料中分别添加0.1%和1%美人鱼发光杆菌灭活菌、0.1%美人鱼发光杆菌活菌配制成3种免疫实验饲料,以基础饲料为空白对照组饲料,每组设3个平行样。对个体质量为(4.83±0.36)g的凡纳滨对虾进行为期20 d的饲养实验,分别在0、5、10、15和20d进行取样,以血清中的酚氧化酶(PO)、酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、超氧化物歧化酶(SOD)和溶菌酶(UL)活性为免疫指标,探讨了美人鱼发光杆菌作为免疫制剂对凡纳滨对虾非特异性免疫效应的影响;在投喂免疫饲料后的第22天,按0.004 2 kg/kg体重的剂量,直接投喂对虾白斑综合征病毒(WSSV)病料,并记录累积死亡率。结果表明,美人鱼发光杆菌免疫实验组对凡纳滨对虾血清中PO、ACP、AKP、UL和SOD活性影响明显高于对照组,并且在饲料中添加美人鱼发光杆菌后,明显提高了对虾抵御WSSV感染的能力。其中0.1%美人鱼发光杆菌活菌实验组的抗病毒感染能力最强,WSSV感染14d内累计死亡率为63.3%±5.8%;而对照组为96.7%±3.3%。研究表明,美人鱼发光杆菌添加在对虾饲料中能提高凡纳滨对虾非特异性免疫水平,增强抵抗疾病的能力,将其作为对虾免疫增强剂具有良好的应用前景。  相似文献   

15.
This study was carried out to investigate the effects of replacing fish meal with dietary Spirulina as a feed supplement on the growth performance and coloration of blue dolphin cichlids (Cyrtocara moorii). Five isonitrogenous (47% crude protein) and isocaloric (17.36 kJ/g digestible energy) diets were for formulated to replace FM with 0, 5, 10, 15 and 20% Spirulina (designated as Control, SP5, SP10, SP15 and SP20 respectively) and fed to the fish (initial body weight, 3.15 ± 0.01 g). Fish were randomly distributed into fifteen 120 L aquariums (26.5 ± 1.00°C), 15 fish per aquarium. The diets were tested in triplicate for 12 weeks. Experimental groups were fed twice daily (09:00 and 17:00) by hand to satiation. At the end of the feeding trial, significantly (p < 0.05) higher weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER) and lower feed conversion ratio (FCR) were observed in fish fed the SP10 diet when compared to the SP20 diet. There was no significant difference in these parameters between the other groups. The skin coloration of blue dolphin cichlid fed a diet containing Spirulina meal was enhanced. The best coloration was observed in the SP15 group. These impressions were objectively validated by chemical determinations of carotenoids extracted from fish skins and passed statistical tests of significance. The study findings show that Spirulina meal does not diminish growth rates except at very high levels.  相似文献   

16.
Two experiments were conducted to quantify the dietary thiamin (experiment I) and pyridoxine (experiment II) requirements of fingerling Cirrhinus mrigala for 16 weeks. In experiment I, dietary thiamin requirement was determined by feeding seven casein–gelatin‐based diets (400 g kg?1 CP; 18.69 kJ g?1 GE) with graded levels of thiamin (0, 0.5, 1, 2, 4, 8 and 16 mg kg?1 diet) to triplicate groups of fish (6.15 ± 0.37 cm; 1.89 ± 0.12 g). Fish fed diet with 2 mg kg?1 thiamin had highest specific growth rate (SGR), protein retention (PR), RNA/DNA ratio, haemoglobin (Hb), haematocrit (Hct), RBCs and best feed conversion ratio (FCR). However, highest liver thiamin concentration was recorded in fish fed 4 mg thiamin kg?1 diet. Broken‐line analysis of SGR, PR and liver thiamin concentrations exhibited the thiamin requirement in the range of 1.79–3.34 mg kg?1 diet (0.096–0.179 μg thiamin kJ?1 gross energy). In experiment II, six casein–gelatin‐based diets (400 g kg?1 CP; 18.69 kJ g?1 GE) containing graded levels of pyridoxine (0, 2, 4, 6, 8 and 10 mg kg?1 diet) were fed to triplicate groups of fish (6.35 ± 0.37 cm; 1.97 ± 0.12 g). Fish fed diet containing 6 mg kg?1 pyridoxine showed best SGR, FCR, PR, RNA/DNA ratio, Hb, Hct and RBCs, whereas maximum liver pyridoxine concentration was recorded in fish fed 8 mg kg?1 dietary pyridoxine. Broken‐line analysis of SGR, PR and liver pyridoxine concentrations reflected the pyridoxine requirement from 5.63 to 8.61 mg kg?1 diet. Data generated during this study would be useful in formulating thiamin‐ and pyridoxine‐balanced feeds for the intensive culture of this fish.  相似文献   

17.
Marine fish farming in Egypt began in 1976 with the culture of gilthead sea bream, (Sparus aurata) as this fish was notably adaptable to brackish and marine pond conditions. Today, marine fish and shrimp farms amount to about 19,000 ha, out of which 42% is already in production while the rest, i.e., 58% is still under construction. In 1997, cultured gilthead sea bream production of 2,250 tons made up 3% of the 75,000 tons total aquaculture catch. In polyculture, usually with the grey mullet and sea bass, gilthead sea bream contributed 440 kg ha–1 to the total yield of 1,700 kg ha–1 (26%) over a period of 16 months. For the same period, the yield of monoculture ponds averaged 100 kg ha–1, while in marine cages, yields ranged from 4–10 kg m3. In 1996–1997, fry of 0.25–1 g and fingerlings 1–10 g with a total of 3 million, were collected from the wild and 1 million fry were produced in the three marine hatcheries out of the four existing ones. The development of sea bream culture in Egypt is now severely inhibited by the shortage of seeds and adequate feeds. Exports of both sea bream and sea bass, during 1994–1996 averaged 1,300 tons per year.  相似文献   

18.
The cockle Cerastoderma edule fishery has traditionally been the most important shellfish species in terms of biomass in Galicia (NW Spain). In the course of a survey of the histopathological conditions affecting this species in the Ria of Arousa, a haplosporidan parasite that had not been observed in Galicia was detected in one of the most productive cockle beds of Galicia. Uni‐ and binucleate cells and multinucleate plasmodia were observed in the connective tissue mainly in the digestive area, gills and gonad. The parasite showed low prevalence, and it was not associated with abnormal cockle mortality. Molecular identification showed that this parasite was closely related to the haplosporidan Minchinia mercenariae that had been reported infecting hard clams Mercenaria mercenaria from the Atlantic coast of the United States. The molecular characterization of its SSU rDNA region allowed obtaining a fragment of 1,796 bp showing 98% homology with M. mercenariae parasite. Phylogenetic analysis supported this identification as this parasite was clustered in the same clade as M. mercenariae from the United States and other M. mercenariae‐like sequences from the UK, with bootstrap value of 99%. The occurrence of M. mercenariae‐like parasites infecting molluscs outside the United States is confirmed.  相似文献   

19.
20.
Plasma estradiol-17 (E2), testosterone (T), 17,20-dihydroxy-4-pregnen-3-one (DHP) and 17,20,21-tri-hydroxy-4-pregnen-3-one (20-S) levels were measured by radioimmunoassay (RIA) in white perch (Morone americana) and white bass (M. chrysops) that were induced to undergo final oocyte maturation (FOM) with human chorionic gonadotropin (hCG). Plasma DHP levels increased in females of both species in association with oocyte germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) and decreased thereafter. Plasma 20-S levels also increased with oocyte GVM in white bass, but were several-fold lower than DHP levels. Circulating E2 and T levels were greatest during GVM and GVBD in both species and decreased to low levels during oocyte hydration and ovulation. Follicles from white perch and white bass which received a priming injection of hCG in vivo, produced both DHP and 20-S in vitro after exposure to hCG and their oocytes underwent GVBD. Ovarian incubates from unprimed fish of either species produced only E2 and T and their oocytes did not complete GVBD. Oocytes from unprimed bass, but not perch, matured when follicles were exposed to hCG in vitro. Both trilostane and cycloheximide blocked in vitro production of DHP and 20-S and oocyte GVBD by white perch follices. DHP and 20-S were equipotent inducers of FOM in the GVBD bioassay. None of several other structurally-related steroids tested were effective within a physiological range of concentrations. These results indicate a role for DHP and 20-S in the control of FOM in white perch and white bass.  相似文献   

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