瘤背石磺产卵规律与天文潮汐关系

The relationship between Onchidium struma's spawning regularity and astronomical tides

为了开展瘤背石磺人工增养殖技术以满足日益增长的市场需求,弄清瘤背石磺的产卵规律是至关重要的。该实验比较三年来瘤背石磺产卵规律趋势,以及潮汐潮高与产卵周期关系,从2013年至2015年,在每年的7月到9月间连续购进同地区的野生瘤背石磺,选取同等规格的瘤背石磺暂养后记录每批瘤背石磺产卵情况,并与潮汐规律以及潮位高度相比较。结果显示:按农历计算,瘤背石磺在每个月的小潮(初七、二十三)前后集中大量产卵,维持6~7 d,在大潮(初一、十五)来临之前一至两天结束产卵,趁大潮时的潮水运动将已出膜的幼体带入海洋。在海水中经过15 d左右的发育,待瘤背石磺发育至大面盘幼虫期时再随下一次大潮回到滩涂。根据结果可以得出以下结论:(1)瘤背石磺的产卵规律与天文潮汐相关,呈现出伴随着小潮出现一次产卵高峰,并且会在开始产卵后的两至三天内出现峰值;(2)理论上说,从小潮到下一个小潮为14 d 19 h55 min,实际上,由于潮汐的迟滞性等原因,瘤背石磺的产卵周期为14 d 21 h 20 min。

In order to develop Onchidium struma’ s artificial aquaculture technology and meet the growing market demand,it is crucial to know O.struma’ s spawning law very well.This study investigated the spawning characteristics within three years and comparatively studied the relationship between spawning and astronomical tides.During three years,O.struma in the same regions was obtained from July to September from 2013 to 2015,and the spawning was recorded each time.After that,the spawning and tidal height was comparatively analyzed.The results showed that O.struma spawned mostly at the neap tide（7 th,23 rd） every month,and this spawning could last 6-7 days by lunar calendar.The spawning stopped at the advent of 1-2 days before the next spring tide,while the tide would take O.struma larva hatched into the ocean.After about 15 days’ development in the sea,O.struma developed into the big veliger and then came back to the beach along with the next tide.It can be concluded that：（1） O.struma spawning rules were related to the tide which showed a peak spawn within the neap tide and reached peak 2-3 days after spawn.（2）Theoretically,it takes 14 d 19 h 55 min from one neap to another neap theoretically.However,in fact,O.struma’s spawning cycle was 14 d 21 h 20 min because of the tidal hysteresis.