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渤海底层的鱼类生物量估计 总被引：4，自引：0，他引：4
本文根据我所1982年4月-1983年5月在渤海进行的底层拖网逐月调查资料(共447站次,鱼类样品200多万尾,计2万多公斤),用传统面积法对渤海底层的鱼类生物量作了估计,并对有关开发利用问题作了讨论.1.渤海底层的鱼类生物量周年平均值是55662t,最高为9月达123824t,最低为3月,只有8333t.这种季节差异与渤海水温变化有很大的关系.底层的鱼类生物量密度周年平均值为0.696t/km2,约为1930年的1/5.2.渤海底层各种鱼类生物量,以黄鲫为最高,周年平均值达10500t,占总生物量的19%.其次是小黄鱼、蓝点鲅、鳀、孔鳐、黑鳃梅童、鲈、美鳐、银鲳、半滑舌鳎、凤鲚、绿鳍马面魨、棘头梅童鱼等.3.渤海底层各月鱼种相对生物量更替最高是4月转5月,达71.9%,最低为3—4月,只有24.2%,周年平均值为43.6%.4.渤海底层取样,带鱼网获量周年平均值只有11g/h,鳓鱼为73g/h,均濒临绝迹.小黄鱼达6.749kg/h,它在渤海底层的总尾数有5亿尾,显示其数量的明显回升.黄鲫为底层优势种(10.7kg/h),鳀鱼为上层优势种,6月达20.1kg/h. 相似文献
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细菌性鱼病对鱼类养殖业危害广、威胁严重。以淡水鱼类和梭鱼等为主要危害对象的细菌出血性败血病危及我国养鱼水域，给渔业生产造成了巨大的损失。目前，鲤鱼的出血性败血症已得到有效控制，海水鱼类如牙鲆、真鲷、梭鱼等的出血性败血症正在研究之中。为防治该病的蔓延，我们于1995年进行了梭鱼出血性败血病病原菌研究，从患病梭鱼病灶处分离到该病的病原菌为嗜水气单胞菌。在此基础上，我们又对防治梭鱼出血性败血病药物的药效进行了比较研究，根据药敏试验结果，筛选出4种安全、有效、价廉的鱼用口服药物氟哌酸、鱼血散、氯霉素和磺胺+TMP。本研究用氟哌酸对梭鱼细菌出血性败血病进行了防治，疗效显著。 相似文献
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人工诱导雌核发育牙鲆的染色体及核型证明 总被引：6，自引：1，他引：5
于1994-1996年,分别在威海海洋渔业捕捞公司（石岛）和鸿洋实业总公司龙须岛育苗场采集人工培育的3－5龄牙鲆亲鱼,采用紫外线照射法使牙鲆精子遗传物质失活,并用冷休克法抑制受精卵第二极体释放,从而获得雌核发育二倍体牙好。原肠期采用空气干燥法、Giemsa染色,得到雌核发育二倍体、正常二倍体及单倍体的染色体制片,进行染色体和核型的分析。结果表明,牙鲆的雌核发育二倍体和正常二倍体的染色体数均为2n=48,核型为48t,即48条端部着色点染色体,臂数NF=48,两者的核型设有明显差异;单倍体为24条端部着丝点染色体;在3个组别中,第一号染色体上都有一明显的次缢痕。雌核发育二倍体牙鲆的诱导率为98％。 相似文献
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STUDY ON EMBRYONIC DEVELOPMENT AND EARLY GROWTH OF TRIPLOID AND GYNOGENETIC DIPLOID LEFI—EYED FLOUNDER, PARALICHTHYS OLIVACEUS （T. et S. ） 总被引：1，自引：0，他引：1
The early effects of chromosomal manipulation of eggs and sperm on the yields of trip-loid and gynogenefic diploid larvae of Paralichthys olivaceus were investigated. Triploidy was achieved by cold shocking fen.ilized eggs at 0 - 2℃ for 45 minutes duration 5 minutes after fen.ilization, and the in-duced triploidy rates were 31.2% - 50% and the relative hatching rates were 53.3% - 99%. Gynnge-aetic diploids were obtained when eggs were inseminated with irradiated sperm and cold shocked at 0 -2℃ for 45 minutes duration 5 minutes after fertihzation. The induced gynogenetic diploid rates and the relative hatching rates were 94 % - 96 % and 48.5 % - 68.5 % respectively. The embryonic development of the triploid experimental group and of the gynogenetic diploid experimental group was delayed at first compared with the control group. But from the gastrula stage, it was not delayed anymore. There were no significant differences in the growth of the triploid experimental group larvae and the control group larvae, and in the growth of the gynogenetic diploid experimental group larvae and the control group larvae ac-cording to Student‘s t-test (α = 0.05). The relationship between the early growth of the triploid experi-mental group larvae and that of gynogenetic diploid experimental group larvae was also studied. 相似文献
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An experiment on the optimum dietary protein content for the black sea bream using semi-purified dietsshowed the optimum content is 50.19% by weight as inferred from the growth rate and food consumptionof the fish. Another experiment on the proper ratio of animal to plant protein in its diet using sandeel as theanimal protein source and peanut cake meal as plant protein source showed that the ratio had great ef-fect on its growth and should be 1.00:0.89—0.96 as judged from the growth rate and food consumptionof the fish. 相似文献
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An experiment on the phosphorus requirement and the proper Ca/P ratio in the diet of the black sea bream using the phosphorus gradient method (with casein as basic diet, sodium dihydrogen phosphate as source of phosphorus, and calcium lactate as source of calcium) showed that growth was greatly affected by the diet's phosphorus content and Ca/P ratio. Inadequate phosphorus in the diet resulted in slow growth and poor food conversion ratio (FCR). Analyses of the fish body showed it contained a high level of lipid but a low level of moisture, ash, calcium and phosphorus. The optimal values of phosphorus and Ca/P ratio in the black sea bream diet are 0.68% and 1:2 respectively. Phosphorus in excess of this optimum value resulted in slow growth or even death. The results of this experiment clearly indicated that phosphorus is the principal mineral additive affecting black sea bream growth. 相似文献
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Hybrids between olive flounder Paralichthys olivaceus and stone flounder Kareius bicoloratus： karyotype, allozyme and RAPD analyses 总被引：2，自引：0，他引：2
The hybrid between olive flounder Paralichthys olivaceus and stone flounder Kareius bicoloratus was produced by artificial insemination of olive flounder eggs with stone flounder sperm. Sinistral and dextral are two types
of hybrid progeny after metamorphosis. Karyotypes of both hybrid flounders are the same as those of the two parental species.
Of the 22 loci examined from 12 allozymes, 12 confirmed hybridization of the paternal and maternal loci in hybrids and no
difference was found in allozyme patterns of sinistral and dextral hybrid fishes. RAPD patterns of these specimens were also
studied with 38 primers selected from 104 tested. Among them, the PCR products of 30 primers showed hybridization of the paternal
and maternal bands. Genetic variation between hybrids and their parental stocks was analyzed by RAPD using 10 of the above
38 primers. The average heterozygosity and genetic distance were calculated. The results suggested that the filial generation
could inherit a little more genetic materials from paternal fish than that from maternal fish.
Supported by National Natural Science Foundation of China (No. 30571445), National High-Technology Research and Development
Program (863 Program, No. 2006AA10A404), and Project from the Ministry of Science and Technology of China (No. 2006DKA30470-017) 相似文献