1998, 22(4).
Abstract:In six geogr aphical populat ions of Carassius auratus gibelio , the ND 5/6 r egion (approximately 2 .5Kb)of mtDNA genome have been amplif ied by the polymerase ch ain reaction (PCR), and the pr oducts were examined using rest rict ion fr agment length polymor phism (RFLP).11 elect rophoresis patterns and 7 haplotypes (genotypes)have been observed .Based on the genet ic distances , the UPG molecular phylogenet ic tr ee of the populat ions was constructed .The results indicate th at the six popula tions of the C .auratus gibelio can be imcorporated into four populat ions , namely , the Heilongjiang and Anhui , the Henan , the Yunnan and Guizhou , and the Jiangxi .The first is the closest to the third . The He nan is much closer to the Heilongjiang and Anhui .The far thest is between the Jiangxi and the other populat ions .
1998, 22(4).
Abstract:Alto gether 240 specimens o f Monop t er us albus w ere studied by examining the to tal leng th and weight fo r age determinat ion. The specimens were collected f rom Tuman Road Bazar f rom Febr uary in 1996 to Januar y in 1997. Age determinat ion w as made by oto lith ( sagit ta) , ver tebra and hyo id-arch bo nes. The result s indicate tha t the hyo id-arch bo nes are mo re suitable fo r a ge determinat io n o f M. albus. Grow th studies w ere made by means of sca les metho d. Tw o commonly fo rmulae W= aLb a nd W= a+ bL wer e a pplied to compute the leng th-weig ht relat ionship o f M . albus. The fo llowing expressio ns wer e der ived f r om: W= 8. 3613L- 300. 3 ( R 2 = 0. 8908) ; W= 0. 0003L 3. 2941 ( R 2 = 0. 9482) .
1998, 22(4).
Abstract:The mandibular organs of the cr ayfish(Procambarus clarkii)are in pairs , These yellow or gans ar e located at the dorsa of the paird mandibles , outside bases of mandibular chit inous tendons .Abundant hemolymph vessels and blood sinuses could be seen in the mandibular organ , the mandibular organ cells ar ranged in cords and surr ounded the blood sinuses .The most dist inguishing features of the typical mandibular organ cells are as follows :(1)The mitochondria and the smooth endoplasmic ret icula are dispersed extensively in the cytoplasma , and the smooth endoplasmic r eticulm occurs in two dist inct forms : cisternal and tubular .(2)The plasma membrane invaginates into cytoplasma and exhibi ts varying degrees of convolution .(3)The basal membr ane outside the plasma membrane is rich in microfilaments and thick .In the vacuola ted mandibular or gan cells , the smooth endoplasmic re ticula almost disappear , the thicken st ructures of mi tochondr ia change and the heterchromatins in the nuclear f orm a cycle near the nucle ar membrane .These modifications indicate th at the synthet ic capacity of cells causes a change , showing a state of cell pr oducts af ter se cre tion .
1998, 22(4).
Abstract:The fo od compo sitio n of 1450 specimens o f Perca f luv iat ilis ( 0+ ~ 9 ) in Xin- Jiang Wulunguhu lake w as analyzed, and the fo od compo sit ion and feeding intensity in dif ferent seasons o f dif fer ent age g ro ups w ere compared. The tempo ral and specia l patterns o f feeding niche w ere also resear ched also. Synthesizing the result s of the study w ith the cha racter s o f this f ish in g row th and repro duct ion, it i s revea led that there may be two eco lo gical gr oups, o ne is the gro up preying on benthic a nimals and zoo plankto ns( 0 ~ 2 ) , the o the r is the gro up preying o n pisciv oro us f ishes( t> 3 ) , and mo st indiv iduals of the former ar e of miniatur e bo dy and early-maturing, w hile most o f the lat ter are la rge- sized and late-matur ing. The feeding st rategy o f this species i s discussed also. The results are helpf ul to fur ther study o n its eco log y a nd make success of it s tr ansplantat ion and domest-i cat io n
1998, 22(4).
Abstract:Seventeen experiment s have been conducted to study the growing per formance o f 5 st ra ins o f Nile t ilapia, including GIFT st ra in, / 780 st ra in, / 880 st ra in, / Egypt0 str ain and / American0 str ain, cultur ed in net-cages, co ncrete tanks and ea rthen po nds pr acticed w ith e ither po lyculture o r mo noculture sy stems in Qingdao o f Yellow Riv er basin, Shangha i and Huzhou of Yangt ze Riv er basin and Guangzhou of Pear l River basin. The three basins represent the majo r a gro-ecosy stems of China. Major results show ed, r eg ardless o f the str ains cultured in what ag ro-ecosystems or culture sy stems, f r om f inger ling to adult stage, the r anks of grow ing r ate w ere GIFT st ra in > / 880 st rain > / 780 str ain > / American0 str ain > / Egy pt0 str ain. The pheno type-envir onmental inter actio n w as not found in the va riat ions of grow ing r ate of dif ferent st rains of the Nile t ilapia.
1998, 22(4).
Abstract:Responses of Megalobrama hof f manni embr yos to various incuba tion water tempe ratures and salini ty were measured in terms of h atchability and survival rate .The upper and lower limit ing incubat ion tempera tur es were est ima ted at 31and 20 ℃respect ively . The opt imum incubat ion temper ature f or Megalobrama hof fmanni embryos was 24 -28 ℃. Time for embr yonic development was inversely related to incubat ion temperature .Eff ects of temperature on embryonic development was gre ater in later period than in the pr evious one .The upper limit ing incubation salinity was 11 , while the opt imum r ange were estimated to be 0 -7 .A certain r ange of salinity had some posit ive cont ribut ions to embryonic development and hatchabil ity .The effects of salinity on Megalobrama hof fmanni embryos wer e not so obvious as the temperature was .
1998, 22(4).
Abstract:Two wa ter purifica tion me thods wer e compared .The biofluidized bed was 3 t imes higher than biof ixed bed in ammonia N loading and ammonia N removal r ate .Distribution and gr owth of bacteria on the f luidized bio-par ticle surface was observed by electronic microscope and nut ri tive agar culture method .On the par t icle surf ace the biofilm was rich and well dist ributed .At the densit ies of 150 000 larvae/m3 , in f ifteen days , the common car p fry gr ew to 12 .58 ±0 .94mm in length and 21 .2mg in weight in the biofluidized bed system , and the survival ra te of larvae was 90 %.
1998, 22(4).
Abstract:Stock sizes of the chub mackerel (Scomber japonicus)from the East China Sea and the area off the mouth of Changjiang r iver were assessed with vir tual populat ion analysis .The r esult showed that stock sizes of chub mackerel fr om the East China Sea and the area off the mouth of Changjiang River were fluctuated between 132 000 -235 000 and between 41 000 -127 000 me tric tones respectively in the past decade .The stock sizes of chub mackerel in recent years were stable on the r elat ively high levels .However , since the actual catches are gradually close to the stock sizes , it seems tha t there is not very much potential for f urther exploitat ion of this species .
1998, 22(4).
Abstract:Both enzymic and nonezymic l ipid oxidation existed in the micr osomes insolated from muscle of gr ass carp .The experimental resul ts showed that Fe3+ or Fe2 ions wer e required for the enzymic lipid oxidation .The ra te of oxidation was highter with Fe2 than tha t wi th Fe3 ions .The opt imum pH for the react ion of both red and white muscle microsome was between 6 .0 and 7 .0 .The inter action of H2O2 with Hb to form activated MetHb was able to init iate nonenzymic catalysis oxidat ion of lipid in microsomal fract ions of both types of muscle .The stongest e ffect of per oxida tion was observed when the r atio of heme group to H2O2 was nearly 1∶1 .
1998, 22(4).
Abstract:The amylase and algalase of the Pacif ic abalone (Haliotis discus hannai) wer e measured during the length of 2 -3 cm by means of spect rophotome ter .The optimum tempe ratures f or amylase and algalase were 30 ℃ and 35 ℃, The opt imum pH values were 6 .24 and 7 .19 .Under the opt imum temper ature the act ive energy of two enzymes were 5 . 03 ×104 J/mol and 1 .33 ×104 J/mol r espect ively ;the act ivi ty of amylase and algalase were detected when eleven metal ions existed .The resul ts indicated that Cu2 + 、Hg2 、Ag 、Pb2 significantly inhibited the act ivi ty of amylase , and other metal ions activated the activity of amylase .Mn2 , Ba2 and Ca2 can act iva te the amylase two t imes of that in cont rol group .For the algalase , Zn2 , Ag , Hg2 , Li2 and Ba2 significant ly inhibited its activi ty , and the other metal ions had no effects on the algalase .
1998, 22(4).
Abstract:The bienzyme metho d used to hydr oly ze f our aquat ic species such as Sesacma, Per na vi ridis L. , Pinctada mar tensi i D. , and H arengula z unasi B. f or the prepar at ion of aquat ic Hydroly ze d Animal Pro te in( HAP) w as studied. The bienzyme invo lves B. Subct ls neutr al pro teinase w ith act ivity 105 L/ g and pepsin w ith act ivity 3 000 L/ g. The deg ree of hydr oly sis by the bienzyme metho d wa s 43. 4% fo r Sesacma, 82. 0% f or Perna vi ridis L. , 82. 6% fo r Pinctada mart ensii D. , and 93. 6% fo r H arengula z unasi B. . More over , the deo do rizat io n and debitterizat ion of hy dro lyzed so lut io ns by means of yeast pow der and f lavo ure ase w ere also studied in this papaer. Thro ugh the pro cesses o f deodo rizat ion , debi tterizat ion, and concentr atio n o r spr ay dr ying, a hig h qua lity pr oduct o f HAP with go od smell and de licia te f lav our w as prepared, w hich can be used as fo od addit ive.
1998, 22(4).
Abstract:Taking the Pseudosciaena crocea as an example , the r ise and fall processes of Pseudosciaena crocea resources are described by the me thod of System Dynamics , and based on the discussion on the behaviour of the model resul t , the reasonable increasing scale of the f ishing fleet is given .The method and result in this paper can be taken as reference for our countr y to f ish other kind of fisheries r esour ces rat ional ly .