Abstract:In present paper, an outline is given of results of investigation concerning regionaland seasonal changes of some criterin of bottom fish communities in the continenta shelf of northern Nan--Hai. Fish collection was made by three research vessels duringMarch 1964 through Febraury 1965. Fifty-one sampling sites were assigned within 8arbitrarysub--areas of the shelf, which cover an area of 137,667 Km². Towing time oftrawlnet around each site was 2 hours, Every sample of fish was considered as a fishcommunity, of which only the data of March, June, September and December weretreated as representatives of spring, summer, fall and winter respectively. Species diversity is the principal criterion of fish community and there are severalmodels for computing the index of diversity. The modified Shannon--Weaver formulawas employed in the present paper. For eliminating the bias arosing from the discre-pancy of weight of individuals in samples, we used biomass units instead of numbers.Thus, the actual formula we used was H" = -∑ from (w_t/w )log₂(w_t/w)where w_t is the biomass of i-th species in sample, w the biomass of sample. The resultsof implementation of biomass units suggest that this modified computing method mightbe convenient for practical purpose, but the values obtained in terms of biomass tendedto be slightly higher then those in terms of numbers. In the range of the indexes of diversity overall sites within the studied periord,the lowest was 1. 41 occurred at a site of V sub-area in September and the highest was4. 40 at a site of IV sub-area in June. In comparing with the published values of H" ofcoastal bottom-trawled fishes, our figures may be ranged as the highest one. An isopleth diagram of H" was drawn, it was found that the distribution patternof isopleth families in different seasons was distinct each other, but no explicit relation-ship could be ruled out, as the data were still insufficient. The relations of H" withshelf-depth and temperature were also investigated and it seems some possible correla-tions could be found. In conjunction with species diversity, 3 other parameters were calculated:number of species contained in community (S); (2) maximum of species diversity(H_(max)); (3) evenness of Species (J). The Pattern of variations was apparent in theindexes calculated. The variation of H_(max) followed the pattern of S, while the evennessof species (J) shows close association with the trend of species diversity (H"). The component of dominant species is a second fundamental critirion of fishcommuncties and we proposed to formulate a concept of dominant species in con-nection with imformation theory, its interpretation being given in detail. Thus, anyspecies of fish comprised 20--60% of catches in one specified sample is defined as adominant species (D. S.); 24 D. S. were observed in 8 sub-areas and 4 months, andtheir frequencies of occurrence in each sub--area and month showed a wide range. Acode diagram is drawn to demonstrate the regional and seasonal distribution of frequen- cy of D. S., so that the transmission and replacemeat of D. S. between areas or seasonscan be found intuitively. But the situation is very complex, therefore the possiblerelationship between species diversity and dominant species still remains unknown, andthe problem of dynamic of dominant species population itself needs further consecutivestudy and data accumulation.

Abstract:This paper deseribes three new species of Ophichthyidae and one new species ofNeenchelidae, collected from the Pingtan Island (Fujian Province) and Sangou FishingGround (Taiwan Strait) in 1974 and 1976. The holotypes and paratypes are depositedin the Laboratory of Fishes, Shanghai Fisheries College. The descriptions of the fournew species are as follows. OphichthyidaeMicrodonophis fasciatus Chu, Wu et Jin sp. nov. (Figure 1) Depth 39.4 in total length, head and trunk 2. 5, head 9. 5. Snout 5. 1 in head, eye9. 4, interorbital 5. 5. Head 2. 7 in trunk. Head and trunk 1. 5 times in length of tail. This new species resembles Microdonophis erabo Jordan et Snyder in teeth on jawsand vomer in one series and the origin of dorsal above gillopening. Howeverin M. erabothe body has two series of large black spots on each side, the pectoral fin is brownishand the length of tail is less than the distance of head and trunk; while the presentspecies has more than 20 black vertical bands, pectorals blackish and head and trunkare 1. 5 times in length of tail. Holotype: No.A0823, total length 630mm., collected from Pingtan Island, October4th, 1974. Callechelys maculatus Chu, Wu et Jin sp. nov. (Figure 2) Depth 42. 3--52 in total length, head and trunk 1. 8--1. 9, head 12. 7--13. Snout6. 4---7. 1 in head, eye 15--16, interorbital 8--9. Head 6. 1--6. 5 in trunk. Tail lessthan head and trunk. This new species resembles Callechelys marmoratus (Bleeker) but the latter iswhite with more or less crowded black spots or irregularly marbled with brown andyellow, origin of dorsal above angle of mouth and head and trunk 1. 7 times the lengthof the tail; but the present species has about more than 10 indistinct black transverse bands on the body, origin of dorsal behind angle of mouth and tail slight shorter thanthe length of head and trunk. Holotype: № A01293, total length 338mm., collected from Pingtan Island,November Ist, 1974. Paratype: № A01318, total length 208 mm., collocted from Ping-tan Island, November 2nd, 1974. Ophichthys brevicaudatus Chu, Wu et Jin sp. nov. (Figure 3) Depth 23. 6 in total length, head and trunk 2. 2, head 9. 3. Snout 4. 8 in head,eye 8. 9. interorbital 5. 8. Head 2. 9 in trunk. Head and trunk 1. 25 times in length oftail. This new species is similar to the Ophichthys stenopterus Cope, with teeth on Jawsand vomer in two series, but the latter has rather slender body, head and trunk 2 timesin length of tail and the dorsal beginning far behind pectoral. However, the body ofthe present species is thick and short, head and trunk 1.25 in length of tail and thedorsal inserted slightly behind above middle of pectoral. Holotype: № A,07185, total length 542 mm., collected from Sangou Fishing Gro-und in April 25th, 1976. NeenchelidaeNeenchelys parvipectoralis Chu, Wu et Jin sp. nov. (Figure 4,5) Depth 16.5 in total length, head and trunk 2.6, head 10.5. Snout 5.6 in head,eye 15. 6, interorbital 5. 9. Head 3 in trunk. Head and trunk 1. 7 times in length of tail. This new species is allied to the Neenchelys buitendijki Weber et Beaufort, but thebody of the latter is slender, depth 19--21 in total length, head 2 in trunk and pector-al larger, 4--4. 5 in head. However, the present species differs from N. buitendijkhaving the body strong, depth 16.5 in total length, head 3 in trunk and pectoral msmaller and weaker, 11. 7 times in head. Holotype: № A01383, total length 248 mm., collected from Pingtan Island,November 11th, 1974.

Abstract:Protosalanx pyalocranius is a small fish, but has fishery importance in HongzeHu. Investigation on the biology of this fish, including spawning, and embryologicaldevelopment, feeding habit, growth and life--span, was made mainly during the years1974--1975. Its diagnoses are the following: Body slender, elongate, subcylindrical anteriorly and compressed posteriorly. Headmuch depressed, with long, flat, pointed snout. Maxillaries ending beyond anteriorborder of eye; lower jaw projecting; two series of teeth on each side of the palatinelower jaw and tongue each with two series of teeth; no fleshy praesymphysial append-age; dorsal fin wholly in a short distance before anal, with about II, 15--17 rays; andanal III, 27--32 rays; petoral fin with a flaplike strang muscular base, with about24--27 rays; candal foked; vertabrae 67--70. Individuals of one year old attain sexual maturity. Spawning season begins from December 10th to March 10th of next year. Ripe eggs with external filaments. Spawn-ing is in the lake bay. Fertilized eggs sink to the bottom of the lake and hatch to friesin about a month at a temperature range of 4. 3°--8. 9℃; after spawning the parentssoon die. The feeding habit chinges with growth of the fish and the main food items forJuveniles below 70 mm. consist of Cladocera and Copepoda. When they attain a bodylenth of about 70 mm., they eat small fish and prawns. The fries grow fast, after three or four months, they reach fishing standards(40--70 mm.). If some measures of protection are taken for their propagation, the fish-yield may be increased.

Abstract:During September-November 1977 ard May-July 1978, two cruises had been ma-de by the R/V Shi--Yan of Nan Hai Institute of Oceanology, Academia Sinica. Theareas of cruises were located in the central region of Nan Hai between 110°--118°Eand 12°--16°30′N. The specimens of 282 tuna fish larvae collected in these two cruisesimcluded yellowfin tuna, Thunnus albacares (Bonnaterre) (95 specimens); the albacore,Thunnus alalunga (Bonnaterre) (7); the big--eye tuna, Thunnus obesus (Lowe) (69); theblue-fin tuna, Thunnus thynnus (Linnaeus)(3); the longtail tuna, Thunnus tonggol(Bleeker)(2); Thunnus spp. (8); the skipjack tuna, Katsuwonus pelamis (Linnaeus)(65); the oceanic bonito, Euthynnus affinis (Cantor) (7); the yaito bonito, Euthynnusaffinis yaito kishinouye (14); the frigate mackerel, Auxis thazard (Lacepede) (3) andAuxis sp. (9). the composition of these species. the characteristics distribution and theirrelation to the temperature and salinity of surface sea waters are discussed in this paper.

Abstract:Protein requirements for black carp (Mylopharyngodon piceus) fingerlings weredetermined by using purifed diet which consists of casein, crystalline amino acids,fish liver oil, white dextrin, crystalline vitamins, mineral mixture and cellulone flour.Prior to investigating the quantitative amino acid requivements of black carp finger-lings, the composition of indispensable amino acids in diets was adjusted to that of wholeegg protein. Thirteen lots, each of 40 fish were raised in polypropylene aquarium.Feeding experiments were continued for 8 weeks. The tests showed that the fish weredecreased in weight when protein level in diet was lesa than 5%, and they were increas-ed obviouslly when the protein level was 5--41%, and there exists a linear relationshipbetween protein level in diet and the weight gained. Excessive protein levels generallyhave toxic effects on fish and will reduce growth and increase mortality. The results of this experiement indicate that the optimum level of protein in dietfor black carp fingerlings should be 41%,based on the growth of fish and food conver-sion ratio. Therefore, the recommended amount of crude protein in practical diets forone year old fish (second-year fish) is 33% and for two years old fish (third-year fish)is 28%.

Abstract:Temperature and salinity show a marked influence upon the incubation perindand nauplius development. If the temperature is higher, the larval development willbe faster and the time needed is shorter. When the eggs and nauplius are placed under the same salinity conditions, andsuitable temperature, the larvae are strong, and the survival rate is high. The mostsuitable temperature for hatching and nauplius stage is 28°±0. 5℃, but water tempera-ture of 35. 5°±0. 5℃ is harmful to the hatching and larval development. If the water salinity is 28. 59‰ to 35. 43‰, the hatching rate is high and the lar-vae are robust. In 20.81‰ salinity, eggs can not be hatched out. In 40.38‰ salinityand temperature at 24°± 0. 5℃ to 28 ±0. 5℃, although incabation is possible but larvaehatched are so weak that they are unable to swim. At the temperature 35. 5°±0 .5℃and the salinity 40. 38‰, the eggs can not be hatched. The nauplius can develop into zoea when the water salinity in 23. 15‰, 28. 59‰or 35. 45‰. In salinity 40. 38‰, the nauplius can develop into zoea, but they are una-ble to swim and the suvival rate is low. In suitable salinity and temperature hatching is comparatively fast, the survival rate is higher.

Abstract:It was possible to estimate the productivity based on the relative abundance indexobtained by catches of juvenile prawns (Penaeus orintalis). Since the resource andthe area of distribution of juvenile prawns in three bays of Po Hai are unequal, itis nacessary to use the weight coefficients by approximate method in the estimation.It is found that the optimal weight coeffcients for Liaodong Wan, Pohai Wan andLaizhou Wan of Po Hai are 1. 75, 4. 25 and 4. 00 respectively. The result of statistical analysis shows that there is a simple linear relationship between the catches and the relative abundance index. At present, within the range ofthe recent fishing effort, the varied effort has little significance in the prawn fishery. In recent years. owing to the increase of the resource of prawns (When the rela-tive abundance index is more than 1,000) it is found that there existed a signifcantdifference in number of the predicted values, as compared with the actual yields. Hen-ce, we have amended the prediction method as follows: 1. The catches are predicted by the relative abundance indexes. Thus, we haveY = 37.57e~(-1.054-3x), where Y the predicted catches, x the relative abundance index. 2. If the relative abundance index was more than 1,000, we may have to predictwith equation (4) and if it was less than 1,000, we may have to predict with equation(3).

Abstract:By using unlabeled enzyme-immunoassay method to examine the gill disease cau-sed by the bacteria Myxococcus pisicola good results were obtained. The experimentsmanifest that the bacteria from different strains gave cross reaction to specific anti-serum, and the enzyme-immunoassay shows positive reaction. A brown color appeared,and the curved slender bacteria could easily be observed under the microscope. In thecross set, including the nomal rabbit serum, PBS-T, the absorbed serum, the Cg25strains or Cg27 strains were used to substitute the bacteria for checking. The results all gave negative reaction, and no brown color appeared. Evident differences could bedistinguished under microscope. If the mucus is taken from the gills of the healthygrass carp for checking, it appears light yellow in color, only the red blood corpusclesgiving dark brown color. This method of examination has certain practical uses for the survey of prevailingmucous bacteria disease and for the dignosis on other fish diseases. It may be also usefulin localizing pathogen of virulent diseases, in tracing the source and the path of infec-tion, and in studying bacterial and parasitological diseases of fishes.

Abstract:本文研究了从马尾藻灰化提碘以后的废水中提取氯化钾的工艺。发现在原料液体中含有大量的钙离子,必须首先把它们除去,才能正常进行蒸发浓缩。采用纯碱除钙的方法在生产上是可行的。本文对料液在蒸发浓缩过程中化学组成的变化进行了系统的研究。发现其中氯化钾达到饱和时的恒沸点为112-113℃;比重为1.25—1.26(29-30°B′e)。蒸发完成液直接冷却至室温,只能得到工业粗钾,不能得到精钾(要求含KCl>90%)。作者根据分部结晶的原理,把结晶分成两部分,取67℃以下部分,则一次结晶即可达到精钾标准。

Abstract:由于鱼类等的习性与栖息水层各不相同,渔场情况又常起变化,在拖网捕捞作业中,运用一些技术措施改变网口的几何形状是提高拖网渔获效果的一个途径。随着电子仪器的应用和捕捞技术的逐步提高,各国渔业工作者都在从事这方面的研究。 本文对现有拖网网口形状的某些计算方法进行了初步探讨,提出了一种较为精确而实用的积分计算法。并将计算结果列成数据用表,用于拖网网口参数的换算。