3种养殖模式下暗纹东方鲀的生长及水质变化

为探讨不同养殖模式对暗纹东方鲀生长及水质的影响,选取无损伤、健康的暗纹东方鲀7000尾,随机分成3种养殖模式:立体种养模式(模式Ⅰ)、单养模式(模式Ⅱ)和混养模式(模式Ⅲ),进行了为期56 d的养殖试验,比较3种养殖模式下暗纹东方鲀的生长速度、成活率以及养殖水质指标的变化。试验结果:模式Ⅰ暗纹东方鲀的成活率(97.10%)高于模式Ⅱ(92.35%)和模式Ⅲ(89.37%),特定生长率(1.83±0.12)%/d]显著高于模式Ⅲ(P<0.05),饲料系数(2.20)则低于其他2种模式;模式Ⅱ下养殖水体的三态氮(TAN、NO2^--N和NO3^--N)无明显变化,其质量浓度略低于模式Ⅰ和模式Ⅲ,模式Ⅲ下三态氮的质量浓度有所升高,而模式Ⅰ下TAN和NO2^--N质量浓度有降低的趋势;3种养殖模式下,池塘水体的化学需氧量(COD)呈现先升后降再升的变化趋势,总悬浮物(TSS)呈现先升高后降低的趋势,其中模式Ⅰ的COD和TSS质量浓度均低于模式Ⅱ和模式Ⅲ;模式Ⅱ和模式Ⅲ下总氮(TN)质量浓度先降后升,而模式Ⅰ的TN质量浓度则是先降后升再降,且在14 d后均显著低于其他2种模式(P<0.05);模式Ⅱ和模式Ⅲ下总磷(TP)质量浓度无明显变化,模式Ⅰ下TP质量浓度在养殖初期有所升高,呈现先升后降的变化趋势,并在56 d时降至最低,显著低于模式Ⅱ和模式Ⅲ(P<0.05)。结果表明,在立体种养模式下,暗纹东方鲀不仅生长快,成活率高,而且栽种蕹菜对池塘养殖水体具有较好的净化作用,能减少池塘养殖水体富营养化,立体种养模式较单养和混养模式更适合暗纹东方鲀养殖。

Growth performance of Takifugu obscurus and water quality variation in three aquaculture modes

To investigate the effects of three different aquaculture modes on growth of Takifugu obscurus and water quality of ponds,a total of 7000 non-damaged and healthy dark Takifugu obscurus were randomly divided and cultured under three modes:planting and farming mode(modeⅠ),individual farming mode(modeⅡ)and hybrid farming mode(modeⅢ),and a 56-days aquaculture trial was conducted.The results showed that the highest survival(97.10%)and the lowest feed coefficient(2.20)were both observed in modeⅠ,and the specific growth rate(1.83±0.12)%/d]of modeⅠwas significantly higher than that of modeⅢ(P<0.05).Among the changes in water quality,the concentration of three-state nitrogen(TAN,NO 2--N and NO 3--N)did not change significantly in modeⅡ,and increased slightly in modeⅢ.The lowest concentration of the three-state nitrogen was observed in modeⅡ.TAN and NO 2--N concentration showed a decreasing trend in modeⅠ.The chemical oxygen demand(COD)showed an apparent trend of“low-high-low-high”in three modes.The total suspended solids(TSS)showed an apparent trend of“low-high-low”with time.The lowest COD and TSS concentrations were observed in modeⅠ.The total nitrogen(TN)concentrations in modeⅡandⅢdecreased first and then increased,while the TN concentration in modeⅠwas increased first and then decreased.The TN concentration in modeⅠwas significantly lower than that in modeⅡandⅢafter 14 days of culture(P<0.05).There was no significant change in total phosphorus(TP)in modeⅡandⅢ.However,the TP concentration in modeⅠincreased first and then decreased,which was decreased to less significantly than modeⅡandⅢafter 56 days of culture(P<0.05).This research shows that among the three aquaculture modes,the Takifugu obscurus of planting and farming mode not only grows fast and had a high survival rate,but also had a better purification effect on eutrophic water in pond culture process,which is more suitable for Takifugu obscurus cultivation than individual farming mode and hybrid farming mode.