1998, 22(1).
Abstract:Sca les w ere used fo r the age determination. The annua-l r ing f eature belongs to the lo oseclo se and cut pa tter n. The a nnua-l ring is f ormed chiefly fr om Oct ober to December . The Do lly va rden charr , Salvelinus mal ma fe eds ma inly on aquatic insects, a nd on small ter re str ial a nimals and o thers. Feeding takes pla ce mainly in summer and aut umn, but it ma y be obser ved a ll the year r o und. Mo st of the fem ale s and ma les r each the f ir st m atur ity in the a utumn o f their thir d y ear o f lif e, although some may r each the first maturity in sec ond y ear . The spawning too k place fr om Octo be r to No vem ber and the individual absolute fecundity r anges fr om 280 to 500 eg gs. Fish spawns o nce in a ye ar in aut umn. The enviro nmental conditio ns of the spaw ning g ro unds need gr av el in the bo ttom, 50~ 70 cm in w ater depth, 1. 5~ 2. 0m/ s in wate r f low ing speed and 5~ 8 e in w ater temper tur e.
1998, 22(1).
Abstract:Effects of dietary polyunsaturated fa tty acids , phospholipids on the survival and growth of Chinese cr ab , Er iocheir sinensis , f rom the megalopoa to the juvenile wer e studied using purif ied diets .The result shows that the sur vival of E .sinensis juvenile is gre atly incre ased by addit ion of the soybean phospholipids .But the sur vival to III juvenile is not significantly changed by only addit ion of the PUFA (C20∶5 +C22∶6 =58 . 5 %), except somewhat incre asing the sur vival from megalopa to the I juvenile .Mor eover , the composi tion of the unsatur ated f atty acids of the juvenile seems to vary significantly with the die tary level .
1998, 22(1).
Abstract:Cellulose acetate membr ane and SDS -polyacr ylamide gel elect rophoresis wer e used to compare the serum components among crucian car p and several stra ins of goldfishes (gold cr ucian , gr ass goldfish , r ed wen goldfish , red dr agon-eye goldfish and red oval goldf ish )from China .Furthermore , these str ains wer e analysed by dual immune dif fusion and convect ive immune elect rophoresis in which ant i-crucian car p serum f rom rabbi t was used .The r esults are as follows :⑴ The serum components and an tigenicity of cr ucian car p and these st rains of goldf ishes are similar in a high degr ee .⑵ It is demonst rated that there ar e some differences in these fishes by the analysis of electrophore tic gr ams and the determination with highly eff icient ant i-serum.These dif ferences conside rably are consistent with the evolut ionary posit ions among these fishes .
1998, 22(1).
Abstract:The growth of juvenile grass carp (initial weight :15 ~ 30 g/ind .) in dif ferent seasons was observed .The seasonal and daily var iat ions of ser um growth hormone of juvenile gr ass carp wer e me asured using a sandwich ELISA system for cyprinid GH .there was a significant se asonal var iat ion in growth ra tes of the juvenile grass carp , the highest growth rate was found in the fish sampled in June ,whereas the lowest growth rate was f ound in the winter .Serum growth hormone(GH)levels also vary on a seasonal basis with the GH level in April , and the lowest levels in February , September and November .In br eeding season , serum GH level in matured female grass carp markedly rised just befor e spawning induction and re tur ned to normal af ter spawning .A reproducible daily r hythm in ser um GH levels of the juvenile grass car p sampled in labor atory was present .The GH levels wer e generally higher at night than in the daytime , and a r emar kable pe ak appe ared at 24 :00 .
1998, 22(1).
Abstract:Diur nal change of standard metabolism and specific dynamic action of Ctenopharyngodon idel la (body we ight in 15 -20g)wer e measured .The mean rate of standard metabolism and me tabol ic energy were 114mgO2/kg·h and 50 .16kJ/kg·d at 20 ℃ respect ively.Heat increment was 38 .64kJ/kg·d which was 10 .09 % of intake energy . Ener gy of standard me tabol ism and heat increment at 28 ℃were 1 .4 and 1 .3 t imes as much as those at 20 ℃.
1998, 22(1).
Abstract:The ef fect o f star vat io n to the growth, feeding abi lity and sur viva l o f red se a bream ( Pagrosomus maj or ) a nd oliv e f lounder ( Paral ichthys ol ivaceus ) larv ae dur ing early deve lopment w ere ex amined in the delay ed feeding tr ials. Re d sea bream larv ae arriv ed the point o f no r eturn ( PNR) at 6- 7 days of age, it s y olk exhausted at 5- 6 days of age. The PNR of o live f lounder larv ae w as one day o r two to three days ahead of yo lk exhaust io n. The initia l feeding ra te w as lowe r, then slow ly increased to the peak w hen the yo lk almost ex hausted, af ter that , it decr eased. The hig hest initia l feeding r ate o f r ed sea bre am w as 86. 7%, and o live f lounder w as o nly 35%. The grow th and surv ival rates decreased w ith increasing o f feeding-delayed t ime. The sur viva l r ate w as not af fected w hen the init ial feeding wa s at the ag e o f 3 days for red sea br eam.
1998, 22(1).
Abstract:The results fr om this study indicate that the cult iva ted Ser iola dumeri li in the sea waters of Fujian Pr ovince breed between May and July ,with a peak per iod from the middle of May to the middle of June .The ma tur ed brood f ish could spawn by an inject ion of HCG , the spawning ra te was up to 20 %~ 90 %.Rate of f ert ilizat ion is 70 %~ 89 .8 %, rate of hatching is 61 .9 % ~ 82 %.Water temper atur e of 22 ~ 28 ℃ and sal inity of 32 ~ 35 wer e sui table f or the gr owth and development of larvae , juveniles and young fish .Dur ing the seeds nursery , the management of water quali ty , the nutr ient of food organisms , and the pr event ion and tre atment of dise ases we re enhanced , al together , 224 thousands juveniles of 33 .5 mm in body length were pr oduced , and a set of seed production techniques were established .
1998, 22(1).
Abstract:The composit ion of fish communi ties showed that the migr ation fish species between river and lake was disappeared in the main area of Taihu Lake , except the stocked species .The main dominant species wer e lake anchovy (Coil ia ectenes), Icefishes and smaller Cypr inids .The coef ficient of associat ion be tween 8 dominant species showed that lake anchovy , Icefishes , Palaemon modestus , Toxabramis swinhonis , and Neosalanx ol igodont is have a similar temporal and spa tial dist ribut ions , and similar prey , but the y have diff erent reproduct ion per iod .Generally , loss or r eduction of a pr eda tor will lower the pr edation mor tali ty of its prey , causing an incr ease of prey densi ty and a concomitant incr ease in interspecific compet ition .
1998, 22(1).
Abstract:The ba culov irus o f Penaeus chinensis which is t ransmitted to o f f springs by eggs is the main content of SPF. It is importantment to cut o f f the v irus t ransmissio n and cult ivate the healthier st rain resources of shrimps. Abov e all, its theo ret ica l and pract ical signif icance are unneglected. This r epo rt ma de use o f the elect ro n micro scope techno logy to examine ba culov irus f rom ova ry, egg, Nauplis, Zo ea, My sis of Penaeus chinensi s to Post lar va, Juveniles of Penaeus chinensis . The result s r eveal there is the baculov iruso id in ov ary, egg and baculov irus in Nauplis, Mysis o f Penaeus chinensi s, Post larv a, Juveniles o f Penaeus chinensis. At the same t ime the re po rt pro vides the po ssible discussio n o f the baculov irus vert ical t ra nsmission in Penaeus chinensi s.
1998, 22(1).
Abstract:While cultur ing of pare nt prawn , an explosive epidemic disease happened during 1991 -1992 in a cult iva ting f isher y company in Shanghai .The mortality was ver y high .18 pr awns of r andom sampling were surveye d in si tu .The unif orm microorganism was found under microscrope in 17 pr awns .S -1 , S -2 st rains were obtained f rom haemolymph and liver of sick pr awn on plate PDA .During the infect ion experiment , the symptom was as same as that of the sick one .S -3 , S -4 str ains wer e isolated f rom the infectious pr awn .Al l the characterist ics of S -3 , S -4 were similar to S -1 , S -2 .S -1 ,S - 2 were proved to be the pathagenic organism, and identif ied to be Torulopsis mogi i .The kinds of effect ive medicine food(Pr awn -Ⅰ , Pr awn -Ⅱ)were developed for pr event ion and cure of the dise ase .
1998, 22(1).
Abstract:This paper r eported the observat ion about “crack shell disesae” of cul tur al abalone baby by microscope and elect ronic microscope .The symptoms are as f ollows :the shell is thin , the edge is turndowning , the hole is l inking , the absor bing abilit ies decrease , and the growing rate is much low.The pathogen is a kind of spher ical vir ion which was determined by observat ion and art ificially infected e xperiment .The virion mainly invaded the blood cells .This studies also observed the histopathological changes of mant le , feet , gill , l iver and crop and pointed out the inf ection-like ch ange appeared in epidermis and connective tissue cells of main organ and the ult rast ructure changes is the mitochondr ion expansion , the r idge disappe ar ing , and the e ndoplasm disintegr ating .The necrosis of digestive, r espir e and move organs accele rated the death of the abalone .The infect ing ch annel is horizontal .Meanwhile the pathogenic characters were discussed .
1998, 22(1).
Abstract:Under the temperature between 20 ℃and 30 ℃,Dicrateria zhanjiangesis was cultured in the seawater containing different concentr ate d(0 .02 ~ 0 .10 μg/L)Malachite green , wi thin 4 days , the Malachite green of 0 .02 μg/L has a slight effect on Dicr ateria , and in the concent rat ions ≥0 .04 μg/ L , with concentr at ion of Malachi te green incre asing , the growth rate , content of chlorophylla , carotene and protein of Dicr ater ia wer e r educed mar kedly .Tempera tur e has an evident effect on toxici ty of Malachi te green , the higher the tempe rature is , the gre ater the toxicity will become .
1998, 22(1).
Abstract: