Abstract:The present paper deals with the feeding habits and seasonal variation of the feedingintensity of striped mullets along the coast of Xiamen. Samples were taken from XinglinWan, the fish ponds of Houjiang Dai, the ditches of Zhongshan Park and Dongdu Coast,during the period from 1961 to 1962. It was found that the young fishes of striped mullets feed chiefly on zooplanktons,such as copepod Iarvae, Lucifer Gammarus, Trichocerca and Brachinus, and that benthicdiatoms are the main food of both the young and adult fishes in Xinglin Wan. The stomach contents of adult striped mullets ware mainly composed of benthicdiatoms and a little amount of Copepoda, Cladocerans, Ostracods, Protozoans, unocellulargreen algae and blue green algae. Besides, a large amount of organic detritus was alsopresent. Generally the striped mullet changed its feeding habit from zooplankton to ben-thic orgauisms. Seasonal changes of the feeding intensity of striped mullets are closely related to the fluctuation of the water temperature. For instance, when the water temperature was raisedto 26℃ in May 1962,the fullness coefficient of the stomach was found to be 3. 65‰. Inwinter, when the water temperature descended to 10.2℃ in January 1962. the fulless coe-fficient was only 0. 19‰.

Abstract:The diurnal fluctuation of serum gonadotropin concentration during the spawningseason was studied in the common carp and two species of the "domestic carps", the grasscarp (Ctenopharyngodon idellus)and the silver carp (Hypophthalmichthys molitrix). In allthe species similar rhythmic surges are observed, mainly occurring in daytime. However,the peak and valley values of the serum gonadotropin concentration of the commoncarp (20-40 vs. 5-15 ng/ml)are considerably higher than those of the grass and silvercarps (2--8 vs. 0. 1--1 ng/ml). This difference suggests that the secretion of gonadotropinof common carp is high enough for modulating its reproductive activity while, the grassand silver carps cannot spawn, unless exogeneous hormones are given. In the presence of LRH--A, the in vitro GTH relcases of the pituitaries collected inthe night is greater than thet in daytime. The significance of this phenomenon isdiscussed.

Abstract:The synthetic anaiogue of hypothalamic luteinizng hormone releasing hormone(LRTJ--A) has been used as a stimulant for induced spamning of fishes. Serum gonadotropin(GTH) levels have been measured by means of radioimmunoassay before and behind spa-wning of grass carp (Ctenopharynodon idellus) and silver carp (Hypophthalmichthysmolitrix). The experiments showed that the spawning of the carps would take place onlywhen the serum gonadotropin levels reached to a "threshold valus of ovulation", i. e. about30--40 times higher than that before the inducement. This reveals that the mechanism ofreproductive physiology of fish, is also represented by the hypothalamus-hypophysis-gonad system as well as in other vertebrates.

Abstract:The Ultrastructure in conchospores of Porphyra haitanensis has been observed underelectronic microscope. Each conchospore is bounded by a thin layer of protoplasmic mem-brane. Within the cytoplasm there is a single stellate chloroplast. There are fusions betweenthe chloroplast envelope and plastid stroma. Thylakoids are separated from one anotherby intervening layers of stroma. Granunles of protein-pigment complexes (phycobilisom-es) are orderly arranged on the surface of the thylakoids. Pyrenoid is an electron dense body in the chloroplast stroma, sometimes, but notalways, it is traversed by derivatives of the thylakoid system. Grains of polysaccharide reserved material,--floridean starch, scatter freely in thecytoplasm. Plastoglobuli can only be found in the stroma of plastids. Only a few lipid bodies are present in the cytoplasm. The nucleus is egg-shaped and contains a single spherical nucleolus. There arenuclear pores distributed on the nuclear membrane. Other materials, such as vacuolesribosomes and mitochondria are also observed in the cytoplasm.

Abstract:In China, fish sauces are usually prepared from small marine fish of low marketvalue. In general, the raw materials are salted in the fishing boat, more than 30% ofsalt (by weight) being used. Therefore the period for fermentation in traditional proces-sing is very long. In this experiment we have tried to use low salt and high temperature processing.The salt was diluted with water to reach a concentration about 20.22 and 24°Be'. Thetemperatures of fermentation were set at 40--45℃ and 50--55℃. The results are indicated as follows: 1. The low salt and high temperature processing not only promotes the speed offermentation, but also increases the yield of the amino acids. 2. When the fermentating temperature is at 40--45℃, the samples deteriorated atthe 5th day, but at 50--55℃, they gave higher yield of amino acids and good flavor. 3. The flavor of the products depends on the degree of salting of the raw materials.Higher salt content and longer salting gives the fish sauce a better flavor

Abstract:Studies on the artificial inducement of reproduction in common eel (Anguilla japon-ica) have been carried out since 1973. The parents were collected from Tai Hu. They were induced by injection with pituitary gland of carp and HCG. The results of induce-ment show that the females can be induced to mature by means of injecting with smalldosage of the gonadotrophie hormones at an interval between 15--20 days each time and5--6 times in total. All the females were matured in 7--8 times, and the method seemsto be of good effect. The spawning of common eel usually takes place in the early morning between 4:00and 6:20 A. M. at water temperature between 18.5--24.5C. The spawning place isjust under the surface of the sea water. Soon after spawning the females begin to takefood and gradualty restore to health. The remnant of ovary absorbs rapidly. Thesephenomena lead us to consider whether the gonad can redevelop and mature again. The 3--days old larvae demonstrated that the digestive organs are incompletelydeveloped, and the yolk sac is nearly absorbed. The intestine is filled with foods andwithin it there is a violent ciliary movement. This may be a kind of special method ofnutrition in transition. The larvae lived 19 days (434 hours).

Abstract:The naked carp (Gymnocypris przewalskii przewalskii (Kessler) ) is the only fisheryproduct in Qinghai Hu and investigation on the resource of this fish is rarely taken. Thetotal catches for the whole Lake was nearly 140,000 metric tons during the period from1958--1976, but both the size of individuals and the yield per year have decreased. It isstill jn question whether the resource of population has declined or the present fishing ismoderate. The study of population of naked carps was carried out during 1975--1977.The general status of resource dynamics is investigated by the use of Beverton--Holt's mathmatical model. By analysing the results of catches of naked carp it shows that the total mortalitycoefficient is 0.68; the natual mortality coefficient is 0. 18; and the fishing mortalitycoefficient is 0. 50. The six data (Pn/R, Pw/R, Yn/R, Yw/R, Wy, Ly) are calculatedunder conditions of different fishing mortality coefficient. They are supposed atdifferent initial fished age (tc). The eumetric catches curve is ploted and the maximumbiomass age is estimated. According to actual measurement and calculation results, it is summarized as follows: 1. The naked carp is a stable population of which the status of development of fisheriesagrees with general law of exploited lake. The average length and average weight of fishedindividual in exploited lake declined in general. In the survey of the latest three yearslength and weight show gradually stable without declination any longer. The populationnumber and fishery yield are relatively stable at present, it is considered that the resourcehas not declined. 2. The results of calculation show that under conditions of initial fished age of 10.0and fishing mortality coefficient of 1.25, naked carps have a standing population of50,000 metric tons, its maximum sustained yield is 4,791 metric tons/year. But thepresent yield (4,200 metric tons/year), obtained under conditions of initial fished age of7. 0 and fishing mortality coefficient of 0. 50. If initial fished age being raised to 10 yearsold (i. e. enlarging the mesh size), the catches by weight may be expected to increase by10 per cent, but it still has certain distance to attain maximum, unless both initial fishedage and fishing effort should be increased, the total yield can reach to maximum. In doingso, it is certain to increase the capital of investment, but the yield and the economicaleffect increase only a little. Thus, compared with intensifying fishing effort, whethereconmically or in fish growth, enlarging mesh size seems profitable. Owing to the resultsmentioned above, we consider it is suitable to maintain present mesh size and keep a yieldof 4, 700 metric tons/year. 3. For ensuring recruitment parent spawners, it must be protected on a basis ofregulations and restrictions. 4. Mathmatical model is used for estimation maximum sustained yield of standing fishpopulation in approximation. The subsequent test of practice and further study is needed

Abstract:1. Sanguinicola megalobramae sp. nov. Diagnosis: Body lanceolate with conspicuous marginal spines except for two extremi-ties, of which the anterior end may be protruded in form of a proboscis with 4--5 rows ofcrepe line. Length 1. 25--1. 74 (1. 54)mm, width 0.23--0. 42(0. 31)mm.Mouth subcircular,ventral, within which has rod-like organellae; buccal tube nerrow, followed by an enlargedpharynx, within which there are eight spindle-shaped glandular cells; oesophagus slenderand long 0. 341 mm, ending in the form of an irregular ball or pyriform shaped intestinalcaecum, 0. 037 mm in length, 0. 035 mm in width. Testes consisting of 18--22 pairs of va-sicles extending on both sides of mid-line, ventral to ovary where it curves toward theleft side and becomes thick-walled seminal vasicle; male genital pore slightly sinistral,opening in a conical papilla on dorsal body surface. Ovary butterfly-shaped, immediatlyposterior to testes, oviduct arising from posterior of ovary,turning sinistrally tomake a loop and then turning to the right, and widening into a spindle-shaped structure,in which containing numerous sperms, and then uniting with the vitelline duct to forman ovovitelline duct; ootype circular in form containing only one egg, uterus short, withsoveral eggs. Famale genital pore situated in front of male. Egg oval in shape, withoutany projection or spine 0. 066--0. 28(0. 178)mm in length nd 0. 018--0. 020(0 .019) mmin width. Miracidium possesed a dish-like eye located at the medium of body. Sporocystoval or ball-shaped, thin walled, consisting of 8 cercaria in various stages of development,parasitized in digestive gland of Gyraulus albus. Host: Megalobrama amblycephala. Intermediate host: Gyraulus albus. Habitat: Bulbus arteriosus. Locality: Hatchery of Wang-Tien lake and Institute of Hydrobiology, Wuchang,Hupei Province. Type specimen: Institute of Hydrobiology. 2. Sanguinicola sp. Diagnosis: Body spindle--shaped, a little smaller than S.megalobramae, length 1.0-1. 2 mm, width 0.2--0.4 mm. Both lateral margins of body armed with spines, whichhave three types, short rod-like on anterier region, long and broad lanceolate on middleand slender at base on posterior, 91--93 in total number. Mouth, buccal tube, pharynx andoesophagus like S. magalobramae, while intestinal intestinal caecum is quite different, beingX--shaped,usually four lobes in number, but sometimes with a small one in addition. Testeswith 22 pairs of opposite or alternate lobes, of which one or two pairs of the middie regionbeing smaller. Ovary round, situated behind testes, ootype cirular, 30.6 in diameteruterus usually with several eggs; vitelline gland ventro-leteral in position, rather few innumber, posterior to ovary; eggs smooth, long oval in dorsal view, triangular in lateral,48--52(43. 0 ) μ long, 15. 3-20. 4(18. 5) μ in. width. Host: Megalobrama amblycephala. Habitat: bulbus arteriosus. Sanguinicolosis of blunt-snout bream occurred in the fish pond of Hupi province,in 1965 and 1973. It always causes the death of small fingerliugs, about 3. 3--4. 5 cm insize. The agencies are two species of bllood fukes, Sanguinicola megalobramae sp. nov. andSanguinicola sp. The morphlogy, ecology and development of the egg, miracidium, oercariae, andadults of agent are observed and described in detail. It is found that the intermediate hostof this blood fluke is a snail--Gyraulus albus Muller. Expriments on artificial infectionof the cercariae to the fish is larvae had been made. The period of egg-laying of this blood fluke is from July to May of the next year.Most of the adults live in the bulbus arteriosus of the heart, and the eggs distribute withthe flowing of the blood current, mainly to gills and kidney. If large number of eggs crowding in the lamellae of the gill, the young fish would besuffocated to death. If large number of cereariae occur in the pond, the infected fish lar-vae would become abnormal or dying. Eliminating tte intermediate host--G. albus, and killing the carcariae in fish pondare proposed for tbe treatment of this disease.

Abstract:The materials were collected in January to June, September to November, 1975; inDecember, 1977; and also in January to August, 1978. Altogether 1,400 samples werecollected by trawling and ranged 26°30'N～34°N and west of 125°30'E. The results are as follows: 1. The relationship between body length and centrum radius is shown by the followinglinear correlation: L = 7.046R + 49.590 r= 0. 938 (FM) L = 7.241R + 46.016 r=0.949 (F) L = 6.555R + 60. 666 R= 0. 906 (M)Where L = body lengh R = centrun radius r = relative coefficient 2. The centrum of the atlas was taken as a material for examining and measuring theannual ring. The annual ring was found between the opague zons and translucent zoneunder transmitted light. The characteristics may be divided into three types. (1) Mono-belt type. (2) Bi--belt type. (3) Poly-belt type. 3. According to the year round measurement of the marginal increment of the cen-trum, it proves that the ring forms once a year. The time of formation is from Decemberto June, mainly between April and June. 4. The average body length and body weight of filefish in each age group are asfollows: Ⅰ age: 119. 5 mm and 44. 5 g, Ⅱ age: 159. 9 mm and 70. 9 g, Ⅲ age: 194. 8 mm and 136. 9g, Ⅳ age: 215. 2 mm and 190. 8g, Ⅴ age. 229. 2 mm and 231. 3 g, Ⅵ age: 245. 9 mm and 283. 5g, Ⅶ age: 266. 3 mm and 390. 0g, Ⅷ age: 280.0 mm and 447.5g,Ⅸ age: 290.0 mm and 547. 5g, respectively.The length of first maturing female is at 158. 2 mm, and the male 162. 6 mm. 5. The length-weight relationship may be predicated by the equation of exponentialtunction. L = 41. 324W 0: 315Where L = body Length W = body Weight 6. Through the observations and analyses of the samples, the maximum life span ofthe species is ebout ten years, the age composition is comparatively simple, age groupe Ⅲand IY predominate in the population, and individuals older then six years occur only in alimited quantity.