广西北部湾滩涂施氏獭蛤中培及养成期养殖密度比较研究

Comparative study on breeding density of Lutraria sieboldii in nursery culture and adult culture in Beibu Gulf beaches of Guangxi Province, China

为探索施氏獭蛤(Lutraria sieboldii)高效的中间培育模式及合理养殖密度,于2021年2月—2022年4月在广西北部湾海域——北海、钦州和防城港海区滩涂,以相同密度梯度采用箱式和筐式两种养殖模式进行中间培育,中培结束后以筐式养殖进行养成实验,对比各阶段施氏獭蛤的生长性能和成活率。结果表明:中培期北海和防城港海区箱式养殖模式比筐式养殖模式表现更佳,而钦州海区筐式养殖模式表现更佳;北海海区适宜养殖密度为1500粒·箱^(−1),防城港海区为1000粒·箱^(−1),钦州海区为500粒·筐^(−1)。养成期北海适宜养殖密度为40粒·筐^(−1),钦州和防城港海区结束养成时成活率为0。3个养殖海区的环境因子调查结果表明:北海海区的水温、滩温、盐度、pH和溶解氧(DO)变化最小,水质环境最稳定,钦州、防城港海区的水质环境变化较大且较不稳定;北海滩涂的底质粒径以粗砂和中砂为主,防城港滩涂以中砂和细砂为主,钦州滩涂以细砂为主。浮游植物调查结果显示,藻属种类和数量由大到小均为北海>防城港>钦州。研究表明,施氏獭蛤海区中培适宜以箱式养殖模式在北海和防城港海区进行,适宜在北海进行海区养成。

In order to investigate the efficient nursery culture mode and reasonable breeding density of Lutraria sieboldii,we had carried out an experiment at three different beaches in Beibu Gulf,Guangxi Province(Beihai,Qinzhou and Fangchenggang)using the same density gradient from February 2021 to April 2022.Two nursery culture modes,box and basket,were employed,followed by adult culture in baskets to compare the growth performance and survival rate of L.sieboldii at each stage.The re-sults indicate that the box culture mode was more effective than the basket culture mode in Beihai and Fangchenggang,while the basket culture mode was more suitable for Qinzhou.The appropriate densities in Beihai,Fangchenggang and Qinzhou were 1500,1000 grains·box^(−1) and 500 grains·basket^(−1),respectively.At the adult culture stage,the appropriate density in Beihai was 40 grains·basket^(−1),and the survival rates at the end of the culture period in Qinzhou and Fangchenggang were 0.The results show that the changes of water temperature,beach temperature,salinity,pH and dissolved oxygen(DO)in Beihai are the smallest and the water quality environment is the most stable.Besides,the water quality environment in Qinzhou and Fangchenggang changes greatly and is unstable.The sediment particle size of Beihai beach is dominated by coarse sand and medium sand,whereas Fangchenggang and Qinzhou beaches is dominated by medium sand and fine sand,and Qinzhou beach is dominated by fine sand.The results of phytoplankton survey indicate that Beihai has the highest quantity and diversity of algae,followed by Fangchenggang and Qinzhou.Thus,it is showed that L.sieboldii is suitable for nursery culture in both Beihai and Fangcheng-gang sea areas,and for adult culture in Beihai sea area.