摘要
报导了对长江口中华绒螯蟹 (河蟹 ,Eriocheirsinensis)蟹苗汛期预报的研究结果。蟹苗汛期决定于河蟹胚胎及溞状幼体发育的生物学因素、水温条件和潮汐?そ诘暮有芳性?2月底 3月初交配抱卵 ,5月初孵出溞状幼体。 1970～ 1981年的资料表明 ,从 3月 1日河蟹开始交配抱卵至大眼幼体 (蟹苗 )回归淡水 ,约需 12 77度日。按这一标准估算 ,在± 2d的变差下 ,12年中有 11年的发汛起始日在估算范围内 ,而若允许将变差时间提高到± 3d ,则 12年中的发汛起始日全部在预测范围内。长江口的大眼幼体要入江 ,必须借助潮汐的动力。而在潮汐半月周期的潮位曲线上 ,只有从起汛期至大汛期 (农历廿七到初三 ;十二到十八 ) ,潮位逐日上升 ,蟹苗才有可能从河口浅海进入江段。综合考虑度日和潮汐两个因素 。
The research result on forecast of fishing season of Chinese mitten-handed crab ( Eriocheir sinensis )seeds at the mouth of Yangtze River is reported. The occurrence of fishing season of megalopa relates to the development of embryo and zoeae of mitten-handed crab, water temperature and tidal period. The crab mates at the mouth of Yangtze River and has berried eggs mainly during the end of February to early March and zoeae hatched in early May. The record from 1970 to 1981 shows that, it needed 1277 days for megalopa to migrate to freshwater after the mating and egg-berrying of the crab on March 1. According to this standard, if the estimable error is allowed of ±2 days, the correct rate of forecasting fishing season could be 92%, whereas the estimable error is allowed of ±3 days, the correct rate could raise to 100%. It is necessary for megalopa to migrate to freshwater with the help of tidal power. However, based on the half a month tidal level curve, the tidal level rises day by day from 27th to 3rd and 12th to 18th of lunar year, and only on such days can megalopa enter the river section through the river estuary and shallow sea. Take the above-mentioned two factors into consideration, the forecast of fishing season of megalopa can be made.
出处
《水产科技情报》
2002年第2期56-60,共5页
Fisheries Science & Technology Information
关键词
长江口
中华绒螯蟹
蟹苗
汛期预报
Eriocheir sinensis Megalopa Tide Fishing season Forecast
