1998, 22(2).
Abstract:During the pea k perio d of it s repr oduct ion, e xter nal mo rphy log ical f eatur es o f go nad w ere under careful o bserv at ion for diploid a nd t riplo id oy ster, Ostr ea cucullata, and w ith a compar iso n of mature o ocy tes and their nuclei in size. The r esult s revealed that go nad in t riplo ids showed poo r develo pment re lat ive to diploids by appear ances, the diameter o f mature oo cytes a nd the ir nuclei of t riplo ids w ere 19. 6% and 17. 6% larger than tho se o f diplo ids, and w ith 70. 3% and 64. 2% larger in vo lume. Histo lo gical sectio ns pr esented that unlike diplo ids, gonadal development w as retarded in t riplo ids, of which the majo rity remained in sta ges of pr olifer at ion and spent , and only some of them dev eloped to growth and mature stages and produce mature o ocy tes and sperm. Three hermaphro dites wer e o bserv ed in t riplo ids sampled, w hich the sex ra tio w as female 7: ma le 1. In addit io n, retardat ion o f go na dal develo pment and hermaphro dit ic phenome no n of tr iplo ids are discussed in this paper .
1998, 22(2).
Abstract:In this paper , the gr ey corr elat ivity analysis is applied to study on the relationships among fishes in high-yield polyculture pond and analysis of effect of dominant factors on net fish yield .The resul ts are as follows :The relat ion between input of grass carp finger ings and output of siliver car ps is the biggest (R =0 .8242), and the relation between input of bighead carp fingerings and output of gr ass carp is the se cond (R =0 .8075). The input of bighead carp fingerings becomes superiority ma ternal factor , the output of siliver carps becomes superiority junior f actor .
1998, 22(2).
Abstract:Mixed principles and me thods with differen t basic water for re ar ing larva of Chinese mit ten cr ab (Eriocheir sinensis)were studied from 1995 to 1996 on the Ping Hu Fisheries Test Farm of Zhej iang Pr ovince .The results were as fol lows : Using freshwater as the basic water in the fish pond for rear ing lar va , six chemical reagents(MgSO4 ,CaCl2 ,KCl , FeCl3 ,H3BO3 , NaCl)must be added to the basic water .Using deep-well water as the basic water the above 6 chemical reagents and KBr , KI ,Na2H2PO4 , CuSO4 must be added to the basic water .The suitable contents of Mg2+ and Ca2 in both the mixed water wer e 484 ~ 816mg/L and 178 ~ 340mg/ L r espect ively at Mg2 /Ca2 (R)of 2 .0 ~ 3 .0 .The study showed rear ing larva with alongshor e estuar y water was the most economical way .I f the contents of Mg2 ,Ca2 or R were not in the above suitable r anges , the basic water could be diluted with freshwater , or concentr ated se awa ter could be added to the basic wate r , then the contents of Mg2 , Ca2 or R could be mixed to the above suitable ranges .
1998, 22(2).
Abstract:Of nitr ogen and pho spho rus nut rients of shrimp po nds, fea ture and behav ior w ere discussed according to inv est ig ato n results. Seasonal change of IN w as much big ger, especia lly in last per iod of shr imp culture, than that of IP w hich w as stable dur ing the sho le cultur e per iod. Both IN and IP o f vert ical dist ribut ion w ere even in the w ater s. The re w as obvio usly seasona l change on IN fo ex isting fo rm. Moreo ver, it was dif ferent f rom the open w aters that NO2 - N w as also o ne o f the main IN forms. In the mo st culture per iod, IN w as in the po or level and , there fore, became the main rest rict facto r o f pho toplankto n pro ductiv ity. Otherw ise, cir cl ing rate o f IN and I P co uld be increa sed by higher density pho to phankto n in shrimp ponds.
1998, 22(2).
Abstract:Nit ro gen a nd phosphorus budget s of shr imp culture pond wer e studied in six enclo sures stocked w ith Penaeus chinensis a t three lev els, i. e, 52 000 ind. / hm2, 60 000 ind. / hm 2 and 75 200 ind. / hm 2 , respect ively. The main results w ere as fo llow s: The largest per centages of N a nd P input w ere feed and fert ilizer, 49. 7% ~ 54. 5% and 47. 5% ~ 50. 1% for N, 30. 0%~ 34. 7% and 65. 1%~ 69. 9% fo r P. Among the items of N and P outputs, the shr imp ha rvest compr ising 9. 06%~ 11. 05% o f total N input and 3. 02% ~ 3. 94% of to ta l P inputs. Uptake by muds r epr esented the majo r lo ss of N and P, comprising 19. 4% ~ 64. 6% of N input and 21. 7% ~ 95. 9% o f P input, w hile the loss thro ugh seepage only compr ising small percentage of the total input s of N and P, i. e, 5. 0% for N and 0. 5% f
1998, 22(2).
Abstract:In this repor t , the histopathology on non-par asitical hepa tit is of shelled turt le , Trionyx sinensis which was farmed in hot-houses was studied .The results showed tha t the liver of tur tles was the most serious focus , and its funct ions were damaged se riously .The typical clinical symptom and pa thological process appeared in the following four stages .The invalid (il l turt le)manifested symptoms compl ice :fat ty degene rat ion and leukocyte of infilt rat ion in the hepa tic t issue , to aquatic degenerat ion , to hepatic aqua tic swell ing and hematoma , to hepatocyte die , to hepatic stiff and ascet ic fluid .Hepa tic funct ion changed from insufficiency to exhaustion with pathological changes .Pathogens and method of tre atment and cont rol on non-parasit ical hepat it is were also inquir ed in the repor t .
1998, 22(2).
Abstract:The pathogen of carp dropsy in Shandong Province was se par ated and confirmed to Aeromonas cav iae by methods of vir ology and art ificial infect ion .An inact ive vaccine with high immunogenici ty against car p dr opsy was made by a simple technological pr ocess .The safe ty , immunological protect ion and valence of this vaccine were studied , and an oral vaccinat ion was carried out in fishery .
1998, 22(2).
Abstract:The changes of actomy osin( AM) in cultured and wi ld praw ns by thermal tr eatment w ere studied biochemica lly and phy sica lly. The experimental result s showed that the so lubility and C a 2+ -ATPase a ct iv ities o f AM decr eased with the increase o f tempe rature, in w hich the cultured pr awn. s decreased mo re rapidly than tho se of the w ild. s. Ther e w as a sma ll dif ference in a ct iv ity between Mg2 -ATPase and Ca2 -ATPase . The ATPase of cultured praw n w as ent irely deactiv ated a t 50 e , w hile the w ild at 55 e . The number o f unmasked-SH gro ups g radually incr ease d f rom 20 to 40 e , then decreased. The hydropho bicit ies of AM incr eased signif ica nt ly w ith the elev at ion o f temperature abo ve 40 e . No change o f ATP sensit ivit ies at no rma l temperature, but decreased rapidly f rom 35 e . All the ment io ned indices in AM were great ly af fected in the temper ature r ang ing f rom 30 to 40 e , howeve r, AM o f cultured praw n w as less stable than the w ild o ne.
1998, 22(2).
Abstract:A new genus and spe cies of goby Pseudor hinogob ius apor us , was collected fr om the br ook of Ou Jiang River system (Xiandu , Jinyun , Zhe jiang Province) in 1997.I ts sensory papillae and exte rnal char acters ar e similar to the species of Rhinogobius , but ther e ar e no sensory canal pores on he ad .The description of the present genus and species as f ollows .
1998, 22(2).
Abstract: