Closed polyculture of Chinese penaeid shrimp,Taiwan red tilapia ,and molluscans(constricted tagelus and bay scallop) was studied from 1995 to 1997 with the enclosure experiment method, on a shrimp farm in Haiyang Coun...Closed polyculture of Chinese penaeid shrimp,Taiwan red tilapia ,and molluscans(constricted tagelus and bay scallop) was studied from 1995 to 1997 with the enclosure experiment method, on a shrimp farm in Haiyang County,Shandong Province. Four structure optimized closed polyculture systems, i.e., the “shrimp tagelus" system, the “shrimp scallop" system,the “shrimp tilapia" system and the “shrimp tilapia tagelus" system,were worked out. All these polyculture systems were superior to shrimp monoculture system in economic and ecological efficiencies. The order of these polyculture systems in efficiencies was “shrimp tilapia tagelus">“shrimp tagelus">“shrimp tilapia">“shrimp scallop". The “shrimp tilapia tagelus" system raised the production by 28% and the utilization efficiency of input nitrogen by 85%.These closed polyculture systems reduced the nitrogen discharge ratio to 6%-8%, instead of 40%-90% in the usual open culture systems. The ecological features of the systems were also investigated and many meaningful results have been obtained. The mechanism enhancing the efficiencies of these systems, the ways to enhance the efficiencies further and those to reuse the sedimented materials are disscussed.展开更多
The morphology of larval and 1st postlarval stages of Penaeus penicillatus are described.Results from comparative studies on larval development of P.penicillatus,P.merguiensis and P.chinensis are as fol-lows: These t...The morphology of larval and 1st postlarval stages of Penaeus penicillatus are described.Results from comparative studies on larval development of P.penicillatus,P.merguiensis and P.chinensis are as fol-lows: These three species could not be identified during their naupliar stages. In the 1st protozoea,the antennule L1/L2 value is 1.7—2.0 in P.merguiensis,but lessthan 1.7 in P.chinensis and P.penicillatus;in the 2nd protozoea,the supra-orbital spine in P.chinensis isnot bifurcated,while those of P.merguiensis and P.penicillatus are bifurcated;in the 3rd protozoea,thereis a minute(or no)dorso-median spine on the posterior margin of the 1st and 2nd abdominal somite in P.chinensis,but they are prominent in P.merguiensis and P.penicillatus.In the mysis and 1st postlarvalstages,P.chinensis differs from P.merguiensis and P.penicillatus in having 9(8 in the other 2 species)longsetae on the exopod of pereopods 1—3;additionally,one dorsal tooth appears on the rostrum of P.chinensis in the 2nd mysis and that展开更多
An enzyme immunoassay technique is developed for detecting the baculoviral midgut gland necrosis virus (BMNV) in penaeid shrimp and beach anieds. An antiserum was obtained from rabbits immunized with a BMNV preparatio...An enzyme immunoassay technique is developed for detecting the baculoviral midgut gland necrosis virus (BMNV) in penaeid shrimp and beach anieds. An antiserum was obtained from rabbits immunized with a BMNV preparation Purified from Penaeus japonicus. γ-globulin was isolated and labelled with horseradish peroxidase (HRP). This reagent was used to detect the virus in penaeid shrimp experimentally infected with the BMNV preparation, in cultured penaeid shrimp and in several beach animals. The technique is specific, simple and sensitive and can be developed into a practical method for the detection of penaeid shrimp viruses. Among 128 tissue samples from 11beach animals, 77 samples gave positive reactions with the enzyme-labelled immunoglobulin against BMNV from P.japonicus. These animals could possibly constitute a horizontal transmission pathway for cultured penaeid shrimp viruses.展开更多
In two penaeid shrimp (Penaeus monodon and Penaeus penicillatus)postlarvae exposed to 10, 50, 500μg/L Cu, Cd and CuLCd(1:1) mixture respectively,the total carbohydrate(CHO), ash, lipid and moisturegradually decreased...In two penaeid shrimp (Penaeus monodon and Penaeus penicillatus)postlarvae exposed to 10, 50, 500μg/L Cu, Cd and CuLCd(1:1) mixture respectively,the total carbohydrate(CHO), ash, lipid and moisturegradually decreased to a little less than that in the controls without exposure to the twe metals asconcentration increased; but the protein amount gradually increased to a little above that in the controls.Cu caused more reduction in CHO, ash, and lipid as compared to Cd. In contrast, reduction in total constituents was not notable in the case of exposure. to 1:1 mixture of both metals.There were negligiblechanges in all components at 10 μg/L exposure of each metal. Cu, like Zn, probably induced synthesis of specific metal binding proteins (metallothionine) causing increase in synthesis of proteins.In mixture,Cd had antagonistic effects on total composition of constituents in postlarvae.展开更多
This paper deals mainly with etiology, pathology, sympotomatology, harmfulness, preventive measures and treatment of larval mycosis (caused by Lagenidium sp. ) and of ciliate disease (caused by Zoothamnium sp. ) of pe...This paper deals mainly with etiology, pathology, sympotomatology, harmfulness, preventive measures and treatment of larval mycosis (caused by Lagenidium sp. ) and of ciliate disease (caused by Zoothamnium sp. ) of penaeid shrimp larvae.展开更多
There has been an increasing emphasis on reducing the environmental impacts of penaeid trawls by modifying their anterior sections.In one Australian estuary,this approach has culminated in a new generic trawl comprisi...There has been an increasing emphasis on reducing the environmental impacts of penaeid trawls by modifying their anterior sections.In one Australian estuary,this approach has culminated in a new generic trawl comprising a slightly smaller mesh size,and steeper and shorter side panels than traditional trawls,combined with a top panel extending forwards of the bottom panel(termed‘lead-ahead’)and no headline floats.This study sought to investigate if an additional simple,cumulative modification(tickler chain)might help promote adoption of the new trawl,via improved penaeid catches.Six volunteer fishers towing pairs of either the traditional or new trawls in double rigs were asked if an observer could accompany fishing trips,and alternately attach a light tickler chain(~3 kg)anterior to the ground gear of one trawl.Regardless of the trawl design,the tickler chains significantly increased the catch weights of penaeids,but relatively more so in the new trawls(by 1.11×vs 1.08×).The tickler chains also significantly increased the number and weight of total bycatch in the traditional trawls(by up to 1.22×),but not in the new trawls-although there were variable species-specific effects.In terms of total effects,the data support using tickler chains to increase the efficiency of the new trawls and their cumulative benefits,and could be promoted to facilitate broader inter-and intra-fleet adoption.展开更多
Tickler chains are simple additions to the ground gears of benthic trawls that can improve the catches of some target species,albeit with considerable variability.The purpose of this study was to decipher some of the ...Tickler chains are simple additions to the ground gears of benthic trawls that can improve the catches of some target species,albeit with considerable variability.The purpose of this study was to decipher some of the technical variability associated with tickler chains used with generic,paired trawls targeting school prawns,Metapenaeus macleayi.In the first of two experiments,single tickler chains were either attached between the trawl otter boards or the wing ends and compared against each other and a control trawl(no tickler chain).Attaching the tickler chain to the otter boards significantly reduced wing-end spread and the trawled area without significantly affecting catches of school prawns.By comparison,attaching the tickler chain to the wing ends maintained spread and resulted in significantly more school prawns being caught(by 1.11×)than in the control trawl,and also fewer numbers of one teleost species,pink-breasted siphonfish,Siphamia roseigaster.In experiment two,a single tickler chain was compared against one with multiple chains and one with a double chain;all attached at the wing ends.Trawls with the multiple-and double-tickler chains had the same wing-end spread as those with the single tickler chain,while retaining up to 1.17×more school prawns,and for the double-chain tickler,45%fewer southern herring,Herklotsichthys castelnaui.The results are attributed to mechanical and visual stimuli affecting school prawns and some fish,respectively,and support maximising the surface area of tickler chains within the wing ends as a means for improving penaeid-trawl species selectivity without affecting swept area.展开更多
Penaeid trawls often have poor ecological efficiencies measured as unwanted bycatches(with high discard mortality)and<100%effectiveness for all penaeids interacting with the ground gear(with some escape mortality)....Penaeid trawls often have poor ecological efficiencies measured as unwanted bycatches(with high discard mortality)and<100%effectiveness for all penaeids interacting with the ground gear(with some escape mortality).This study investigated the utility of varying ground-chain size(8-vs 10-mm diameter(Ø)stainless-steel chain)and the present or absence of a tickler chain(4-mmØ)for improving efficiencies an Australian fishery diurnally targeting school,Metapenaeus macleayi and eastern king prawns,Penaeus plebejus.There were no treatment effects on wing-end spread and therefore areas trawled.Irrespective of the tickler chain,increasing the ground-chainØreduced catches of total penaeids(by 14%)and jellyfish,Catostylus mosaicus(by 39%)-results speculatively attributed to variation in ground contact and/or a slightly higher footrope in trawls with the 10-mmØchain.By comparison,installing the tickler chain had no effect on eastern king prawns,but increased catches of school prawns(by 1.13×)and bycatches of blue swimmer crabs,Portunus armatus(1.52×;a species with a low discard mortality)and jellyfish(1.23×),while reducing bycatches of two species with high discard mortalities:southern herring,Herklotsichthys castelnaui(by 38%)and squid,Uroteuthis sp.(37%).The results were attributed to the tickler chain producing(1)mechanical stimuli that augmented the capture of benthic-orientated school prawns(but not eastern king prawns owing to diel variations in emergence from the substrata),blue swimmer crabs and jellyfish;and(2)visual stimuli that possibly enabled some southern herring and squid to detect the trawl and escape.The data show tickler chains can improve trawl efficiency for penaeids with at least some positive effects on bycatch that should be rationalised in terms of species-specific vulnerabilities to unaccounted fishing mortality.展开更多
基金Project3 94 3 0 1 50supportedbyNSFC .WorkalsosupportedbytheNationalKeyProgramfortheNinth Five Year PlanunderGrantNo.96 92 2
文摘Closed polyculture of Chinese penaeid shrimp,Taiwan red tilapia ,and molluscans(constricted tagelus and bay scallop) was studied from 1995 to 1997 with the enclosure experiment method, on a shrimp farm in Haiyang County,Shandong Province. Four structure optimized closed polyculture systems, i.e., the “shrimp tagelus" system, the “shrimp scallop" system,the “shrimp tilapia" system and the “shrimp tilapia tagelus" system,were worked out. All these polyculture systems were superior to shrimp monoculture system in economic and ecological efficiencies. The order of these polyculture systems in efficiencies was “shrimp tilapia tagelus">“shrimp tagelus">“shrimp tilapia">“shrimp scallop". The “shrimp tilapia tagelus" system raised the production by 28% and the utilization efficiency of input nitrogen by 85%.These closed polyculture systems reduced the nitrogen discharge ratio to 6%-8%, instead of 40%-90% in the usual open culture systems. The ecological features of the systems were also investigated and many meaningful results have been obtained. The mechanism enhancing the efficiencies of these systems, the ways to enhance the efficiencies further and those to reuse the sedimented materials are disscussed.
文摘The morphology of larval and 1st postlarval stages of Penaeus penicillatus are described.Results from comparative studies on larval development of P.penicillatus,P.merguiensis and P.chinensis are as fol-lows: These three species could not be identified during their naupliar stages. In the 1st protozoea,the antennule L1/L2 value is 1.7—2.0 in P.merguiensis,but lessthan 1.7 in P.chinensis and P.penicillatus;in the 2nd protozoea,the supra-orbital spine in P.chinensis isnot bifurcated,while those of P.merguiensis and P.penicillatus are bifurcated;in the 3rd protozoea,thereis a minute(or no)dorso-median spine on the posterior margin of the 1st and 2nd abdominal somite in P.chinensis,but they are prominent in P.merguiensis and P.penicillatus.In the mysis and 1st postlarvalstages,P.chinensis differs from P.merguiensis and P.penicillatus in having 9(8 in the other 2 species)longsetae on the exopod of pereopods 1—3;additionally,one dorsal tooth appears on the rostrum of P.chinensis in the 2nd mysis and that
文摘An enzyme immunoassay technique is developed for detecting the baculoviral midgut gland necrosis virus (BMNV) in penaeid shrimp and beach anieds. An antiserum was obtained from rabbits immunized with a BMNV preparation Purified from Penaeus japonicus. γ-globulin was isolated and labelled with horseradish peroxidase (HRP). This reagent was used to detect the virus in penaeid shrimp experimentally infected with the BMNV preparation, in cultured penaeid shrimp and in several beach animals. The technique is specific, simple and sensitive and can be developed into a practical method for the detection of penaeid shrimp viruses. Among 128 tissue samples from 11beach animals, 77 samples gave positive reactions with the enzyme-labelled immunoglobulin against BMNV from P.japonicus. These animals could possibly constitute a horizontal transmission pathway for cultured penaeid shrimp viruses.
文摘In two penaeid shrimp (Penaeus monodon and Penaeus penicillatus)postlarvae exposed to 10, 50, 500μg/L Cu, Cd and CuLCd(1:1) mixture respectively,the total carbohydrate(CHO), ash, lipid and moisturegradually decreased to a little less than that in the controls without exposure to the twe metals asconcentration increased; but the protein amount gradually increased to a little above that in the controls.Cu caused more reduction in CHO, ash, and lipid as compared to Cd. In contrast, reduction in total constituents was not notable in the case of exposure. to 1:1 mixture of both metals.There were negligiblechanges in all components at 10 μg/L exposure of each metal. Cu, like Zn, probably induced synthesis of specific metal binding proteins (metallothionine) causing increase in synthesis of proteins.In mixture,Cd had antagonistic effects on total composition of constituents in postlarvae.
文摘This paper deals mainly with etiology, pathology, sympotomatology, harmfulness, preventive measures and treatment of larval mycosis (caused by Lagenidium sp. ) and of ciliate disease (caused by Zoothamnium sp. ) of penaeid shrimp larvae.
基金This study was funded by the New South Wales Department of Primary Industries。
文摘There has been an increasing emphasis on reducing the environmental impacts of penaeid trawls by modifying their anterior sections.In one Australian estuary,this approach has culminated in a new generic trawl comprising a slightly smaller mesh size,and steeper and shorter side panels than traditional trawls,combined with a top panel extending forwards of the bottom panel(termed‘lead-ahead’)and no headline floats.This study sought to investigate if an additional simple,cumulative modification(tickler chain)might help promote adoption of the new trawl,via improved penaeid catches.Six volunteer fishers towing pairs of either the traditional or new trawls in double rigs were asked if an observer could accompany fishing trips,and alternately attach a light tickler chain(~3 kg)anterior to the ground gear of one trawl.Regardless of the trawl design,the tickler chains significantly increased the catch weights of penaeids,but relatively more so in the new trawls(by 1.11×vs 1.08×).The tickler chains also significantly increased the number and weight of total bycatch in the traditional trawls(by up to 1.22×),but not in the new trawls-although there were variable species-specific effects.In terms of total effects,the data support using tickler chains to increase the efficiency of the new trawls and their cumulative benefits,and could be promoted to facilitate broader inter-and intra-fleet adoption.
文摘Tickler chains are simple additions to the ground gears of benthic trawls that can improve the catches of some target species,albeit with considerable variability.The purpose of this study was to decipher some of the technical variability associated with tickler chains used with generic,paired trawls targeting school prawns,Metapenaeus macleayi.In the first of two experiments,single tickler chains were either attached between the trawl otter boards or the wing ends and compared against each other and a control trawl(no tickler chain).Attaching the tickler chain to the otter boards significantly reduced wing-end spread and the trawled area without significantly affecting catches of school prawns.By comparison,attaching the tickler chain to the wing ends maintained spread and resulted in significantly more school prawns being caught(by 1.11×)than in the control trawl,and also fewer numbers of one teleost species,pink-breasted siphonfish,Siphamia roseigaster.In experiment two,a single tickler chain was compared against one with multiple chains and one with a double chain;all attached at the wing ends.Trawls with the multiple-and double-tickler chains had the same wing-end spread as those with the single tickler chain,while retaining up to 1.17×more school prawns,and for the double-chain tickler,45%fewer southern herring,Herklotsichthys castelnaui.The results are attributed to mechanical and visual stimuli affecting school prawns and some fish,respectively,and support maximising the surface area of tickler chains within the wing ends as a means for improving penaeid-trawl species selectivity without affecting swept area.
基金This study was funded by the New South Wales(NSW)Department of Primary Industries
文摘Penaeid trawls often have poor ecological efficiencies measured as unwanted bycatches(with high discard mortality)and<100%effectiveness for all penaeids interacting with the ground gear(with some escape mortality).This study investigated the utility of varying ground-chain size(8-vs 10-mm diameter(Ø)stainless-steel chain)and the present or absence of a tickler chain(4-mmØ)for improving efficiencies an Australian fishery diurnally targeting school,Metapenaeus macleayi and eastern king prawns,Penaeus plebejus.There were no treatment effects on wing-end spread and therefore areas trawled.Irrespective of the tickler chain,increasing the ground-chainØreduced catches of total penaeids(by 14%)and jellyfish,Catostylus mosaicus(by 39%)-results speculatively attributed to variation in ground contact and/or a slightly higher footrope in trawls with the 10-mmØchain.By comparison,installing the tickler chain had no effect on eastern king prawns,but increased catches of school prawns(by 1.13×)and bycatches of blue swimmer crabs,Portunus armatus(1.52×;a species with a low discard mortality)and jellyfish(1.23×),while reducing bycatches of two species with high discard mortalities:southern herring,Herklotsichthys castelnaui(by 38%)and squid,Uroteuthis sp.(37%).The results were attributed to the tickler chain producing(1)mechanical stimuli that augmented the capture of benthic-orientated school prawns(but not eastern king prawns owing to diel variations in emergence from the substrata),blue swimmer crabs and jellyfish;and(2)visual stimuli that possibly enabled some southern herring and squid to detect the trawl and escape.The data show tickler chains can improve trawl efficiency for penaeids with at least some positive effects on bycatch that should be rationalised in terms of species-specific vulnerabilities to unaccounted fishing mortality.
