• Volume 11,Issue 3,1987 Table of Contents
    Select All
    Display Type: |
    • >PAPERS
    • CHANGES OF SERUM STEROID LEVELS DURING OVULATION IN RAINBOW TROUT(SALMO GAIRDNERI)

      1987, 11(3):205-213.

      Abstract (2077) HTML (0) PDF 754.60 K (1730) Comment (0) Favorites

      Abstract:Serum levels of 17β-oestradiol (17β-E2.), testercon? (T) and17α-hydroxy-20β-dihydropogesterone (17α20βP) were measeured in female rainbowtrouts (Salmo gairdneri) during their first ovulation. 17β-E2 fell from 18.1 ng/ml15 days to 2ng/ml 3 to 6 days prior to ovulation, and it was 0.9ng/ml duringovulation. Testosterone reached to a peak 1evel of 143. 3ng/ml ct 9 days prior to ovula-tion, then the level fell to 24. 3ng/ml during ovulation. At 15 days before ovulation,17α 20β P levels were either nondetectable or extremely low, but it rose rapidly from9 days and reached to a peak level of 350.6ng/ml at 3 days before ovulation. Whileovulating the level become to 302.2ng/ml. This work provides further evidence for17α 20β P that plays an important role in final maturation of oocyto. 17β-E2. maypossibly regulate the timing of 17α 20β P surge. Injection of synthetic chum salmon (Oncorhychus keta)gonadotrophin-releasinghormone (s-GnRH) and its analogue (s-GnRH-A), the changes of serum 17β-E2, Tand 17α 20β P levels are similar to that of natural ovulation. s-GnRH and s-GnRH-Ainjected fish ovulated a week earlier and synchronous than those of control.

    • THE AGE AND GROWTH OF ROUND SCAD OF ZHEJIANG OFFSHORE WATERS

      1987, 11(3):215-223.

      Abstract (2212) HTML (0) PDF 555.25 K (1374) Comment (0) Favorites

      Abstract:Round secad (Decapterus maruadsi), a widely distributal fish.is one of the main targets for purse seine fishing in China. This study is based onobservation of scales and otoliths of 644 fishes collected from commercial catches offZhejiang coast from January of 1981 to March of 1983. The results are summarized asfollows: 1. The scales and otoliths are reliable in age determination of this species. Newrings are formed once a year, and they usually appear in May and June. 2. The body length and the scale length prescnt a linear relation: L=1.259R-2 .691.The correlation equation of the body length and weight is W=1.652×10~(-5)L~(2.947). 3. The growth rate of the fish is uneven within a year. The growth is rapidfrom May to Oct. and is slow from Nov. to April. 4. The general law of growth between years may be expressed by von Dertalanf-fy growth equation. The changing feature in the growth process is charanacterized bythe body length and weight tending towards the asymptotic value with the increase oftime. The growth rew and acceleration tend to the zero gradually, The length seemedto be more rapid tending to the terminal than the weight.

    • STUDIES OF INSEMINATION CYTOLOGY IN HYBRIDIZATION BETWEEN GRASS CARP AND PRESHWATER BREAM

      1987, 11(3):225-232.

      Abstract (2108) HTML (0) PDF 4.39 M (1570) Comment (0) Favorites

      Abstract:This paper presents studies of inseination cytology on hybri-dization botween grass carp (Ctenopharyngodon idellus) and freshwater bream (Me-galobraman terninalis). The experiment reveals that the spermatozoon of the bream canether the egg cytoplasm of grass carp, then induces the emergence of the aster andfinally forms the male pronucleus. At the same time, the activated egg begins tocomplete the second polar-body. After the male and female pronulei come into being,they become contacted and fused. The author has ever studied the chromosomes of grass carp, the freshwaterbream and the F1, hybrid. It has been found that the F1 hybrid belongs to triploidalthough the parents are diploid. Hence it is gussed that the reason for producingtriploid is to emerge mitosis at the time of fertilization or to reserve seccnd polar-body.

    • THE EFFECT OF DESICCATION ON SOME MARINE ALGAE IN PHOTOSYNTHESIS,RESPIRATOIN AND GROWTH

      1987, 11(3):233-240.

      Abstract (2103) HTML (0) PDF 2.74 M (1462) Comment (0) Favorites

      Abstract:Desiccated in room for different times (2--12 hrs), the dehy-dration rates of all four algae reach to ninety percent. Desiccation for 2--12 hrsstimulates the gross photosynthesis rate on Porphyre yezoensis. Desiecated in 7 hrs.the gross photosynthesis rate of Ulva lactusa gets a stimulation, but longcr than 8 hrsit shows inhibition. The same result on Monostroma nitidum: 5 hrs stimulates, longcrthan 6 hrs inhibits. Of all the different desiceation times, Ulva pertusa shows thegroso photosynthesis rate lower than its control. After desiccated for 2--12 hrs, the net photosythesis rate of the four algae all decrease, while in contrast to their respira-tion rates, all increase to some degree.

    • THE DEVELOPMENT OF FERTILIZED EGG AND LARVAE OF SPOTTED GRUNT

      1987, 11(3):241-246.

      Abstract (2280) HTML (0) PDF 386.59 K (1512) Comment (0) Favorites

      Abstract:The present paper is the observation on the development of theartificially fertilized egg and larvas of the spotted grunt, Pomadasys hasta Bloch,which is an importnant fish of economic value and inhabits at the bottom of inshoresea. The spotted grunt usually aggregate in shoals and migrate towards the shallowwaters along the coast of the northern part of the Nan Hai sea,where the temperatureis 18--26℃, and salinity is 31.00--34 .35‰. The spawners were obtained from thetrawlers in the vicinity of the esturary of Pearl river(21°54'N, 113°30'E) in theyear of 1964. The eggs are apherical in shape, isolated and buoyant, measuring 0.77--0.81mm in diamter. The yolk is colourless and tranaparent with a single oil globule of0.19--0.23 mm in diameter. The blastopore closeed at 13 hours after inseminationwhen the water temperature was 24℃. The melanophores appears on the dorsal partof the embryo at 16 hours after insemination. The larvae hatched at 20 hours afterinsemination with water temperature of 25℃. The newly hatched larvae attained totallength of 1.61 mm and the fin membrance is colourless and transparent. Melano-phores appeared behind the eyes and on the dorsal part is well as at the rear of anus.Yellow sac was absorbed 2 days after hatching and the yellow pigment disappeared 3days after hatching. During this time the stellate melanophores occurred along the ventral part of the tail. The larvae all died 5 days after hatching.

    • >RESEARCH NOTES
    • THE EAGLE-CLAW SHRIMP TRAWL WITH SHRIMPDRIVING DEVICES

      1987, 11(3):247-250.

      Abstract (1966) HTML (0) PDF 261.38 K (1520) Comment (0) Favorites

      Abstract:鹰爪虾(Trachypenaeus curvirostris)是黄海北部的重要捕捞对象之一,其中山东省全年捕获量一般为3000~7000吨,近几年资源旺发,产量可达万吨以上。应用普通拖网捕捞鹰爪虾,不仅产量低,而且网具损坏和丢失严重。针对这种情况,山东省海洋水产研究所,从1981年开始改革鹰爪虾拖网。经过反复试验,于1984年研究成功装有驱虾装置的鹰爪虾拖网。连续四年的生产实践证明,该网比普通网增产鹰爪虾30~50%,并且在渔获物中杂质少,网具寿命长。

    • A STUDY OF ECOLOGICAL GROWTH EFFICIENCY OF STONE FLOUNDER AND BANDED DOGFISH

      1987, 11(3):251-253.

      Abstract (1899) HTML (0) PDF 2.22 M (1270) Comment (0) Favorites

      Abstract:海洋鱼类自然生态研究在我国已经进行了三十多年,积累了大量资料,揭示了许多规律。但是由于野外调查本身的局限性,一些重要规律的深入探讨还需要依靠实验手段的配合。有关鱼类在海洋生态系统中的能量转换规律的研究,便是这方面的一个例子。鱼类生态效率的测定,是海洋生态系统中能量转换研究的重要环节。它对水域生产力和海洋牧化中某些种类的增殖潜力的估计有重要作用。

    • AMINO ACIDS CHANGES DURING THE EARLY DEVELOPMENT OF GRASS CARP

      1987, 11(3):255-257.

      Abstract (2063) HTML (0) PDF 243.56 K (1755) Comment (0) Favorites

      Abstract:氨基酸是构成蛋白质的基本单位,它参与卵母细胞的代谢。正在生长的卵母细胞中,卵黄的合成(即蛋白质)很旺盛,而草鱼胚胎主要以卵内贮备的营养物作为早期发育及器官分化所需的能量来源。关于鱼卵氨基酸的代谢,Michizo Suyama and Taheshi Suzuki(1978)用柱层析方法对红鳟鱼鱼卵中结合和游离的氨基酸进行了研究,他们证明红鳟鱼鱼卵的谷氨酸和天门冬氨酸含量最高。Takeshi Suzuki andMichizo Suyama(1983)年发现成熟鱼卵中游离和结合的氨基酸组分有较大的变化。他们还发现游离氨基酸在各种鱼中不同。Kavanau(1953,1954a,b)研究发现海胆卵发育过程中氨基酸浓度有着周期性的变化,受精时氨基酸代谢变化急剧。尽管有关鱼类早期发育氨基酸的代谢有过一些研究,但各种鱼类的生殖过程都有它的特殊性,因此表现在鱼卵及早期胚胎发育的化学物质代谢方面也会存在很大差异,这就决定了各种鱼类的发有特征。草鱼是四大家鱼之一,其胚胎发育各时期水溶性氨基酸的代谢至今尚未见报导。因此我们系统地对草鱼早期胚胎发育各时期水溶性氨基酸的代谢进行了定量分析。该工作将从理论上阐明草鱼胚胎发育时期水溶性氨基酸的代谢特征,从而对生产实践提供参考资料。

    • >ROUNDUPS
    • ADVANCE IN CRYOPRESERVATION OF FISH SPERMATOZOA

      1987, 11(3):259-267.

      Abstract (2008) HTML (0) PDF 2.92 M (1671) Comment (0) Favorites

      Abstract:鱼类精液超低温冷冻保存研究是从五十年代开始的,经过三十年的努力已取得很大成就。国外的工作主要是在海水鱼类和鲑科鱼类中开展的,并在某些鱼类,如鳕鱼、虹鳟、鲑鱼,大马哈鱼等的精液冷冻保存中获得成功。不少学者还对精液冷冻的原理,冷冻保存的技术环节如稀释液的配制、抗冻剂的种类及浓度、降温平衡、冷冻速度及保存方法等进行了较为详细的研究。我国在鱼类精液超低温冷冻保存方面的工作开展得比较晚。

    • >PAPERS
    • BIOLOGICAL CHARACTERISTICS AND RESOURCES STATUS OF THREE MAIN COMMERCIAL FISHES IN OFFSHORE WATERS OF CHINA

      1987, 11(3):187-194.

      Abstract (2225) HTML (0) PDF 577.75 K (1815) Comment (0) Favorites

      Abstract:Large yellow croaker Pseudosciaena crocea, little yellow croakerP.polyactis and largehead hairtail Trichiurus lepturus were three most impotantcommercial fishes in Chinese marine fishery. This paper mianly deals with the dis-tribution, migration of these fishes and their biological characteristics. The paper alsolooks back the process of exploitation and the changes in the yield and abundance ofresources from 1955 fo 1984. The conclusion points out that the violent fluctuationin the yields and the remarkable changes in the population structure were mainly dueto overfishing during the receni 20--30 years. It is more soitable to define the potential yield of long life-span fishes as 1/3 .M.P, (fishable population abundance)or 1/3. 5.M. B. according to our own experiment. In order to improve radically thefish resource status of the sea area, recent fishing intensity should be reduced on alarge scale. To realise this, a great number of problems should be solved such as thoseconcerned with socity, economics and legslation as well as international cooperationwith other countries or regions.

    • THE RELATION ON THE ENVIRONMENT OF FISHING GROUND WITH THE OCCURRENCE OF HAIRTAIL IN WINTER OFF THE MIDDLE PART OF ZHEJIANG

      1987, 11(3):195-203.

      Abstract (2009) HTML (0) PDF 648.60 K (1320) Comment (0) Favorites

      Abstract:The present paper is a study on the basis of the investigation ofhydrographic data of the middle fishing ground off Zhejiang in 1977--1982. The occurrence of hairtails in the fishing ground belongs to seasonal migration,and the shoal is more sensitive to the change of environment conditions. Thereforethe season alternation of hydrography in fishing ground, the annual distribution ofwater temperature and the latitudal fluetuation of mixed water system ect, should beused as indices in determining the advance of fishing season and the variance, orshifting of central fishing ground in practice. If the alternation between summer and winter of the fishing ground hydro-graphy appears in adance, the fish occurrence will be early in time, otherwise it willdelay. If the water temperature distribution presents‘cold year pattern', it would delay. The fishing season should be in advance, otherwise. There is an evident rulativity between the latitudal fluctuation of 34‰ isosalinecure (Namely, high isosaline curve) and the central fishing ground, If the highisosaline curve inelines to the west, the fish occurrence tends to inshore, otherwise ittends to offshore.

Current Issue


Volume , No.

Table of Contents

Archive

Volume

Issue

Most Read

Most Cited

Most Downloaded