中华鲟自然繁殖行为发生与气象状况的关系

对中华鲟历史及现存产卵场共55次自然繁殖活动发生起始日的天气类型和气象要素(包括风、降水量、气温、气压、日照时数、湿度和云)状况及其变化进行了统计分析.结果表明;中华鲟自然繁殖行为的发生对阴雨天具有一定的选择性,而对多云天气则具有一定的回避性;产卵起始日前后天气类型的剧烈变化是诱导中华鲟自然繁殖行为发生的一个有利因素,现存产卵场内连续晴天天气也较容易诱发中华鲟自然繁殖行为的发生;除现存产卵场产卵起始日平均气温在第1批和第2批产卵活动之间表现出极显著差异外,产卵起始日其余气象要素在第1批产卵活动、第2批产卵活动和产卵起始日时间窗(最早和最晚产卵起始日的时间跨度范围)范围内,三者之间并没有表现出显著的差异;第1批和第2批产卵活动产卵起始日的气压变动呈现出一定程度的相反趋势;与历史产卵场不同,现存产卵场产卵起始日的日照时数与水位和含沙量之间并不具有相互制约和补充的关系.结果显示气象状况也是影响中华鲟自然繁殖行为发生的重要因素.

Relationship Between Meteorological Conditions and Natural Reproduction Behavior of Chinese Sturgeon

In order to explore the relationship between meteorological conditions and the commencement of natural spawning of Chinese sturgeon (Acipenser sinensis), a total of 7 meteorological elements (including wind, rainfall, temperature, air pressure, sunshine hours, humidity and cloud) in the initial spawning day of 55 spawning activities within the years(1963-1965, 1970-1975, historical) and (1983-2006, present) in respective spawning areas were studied. The results show that the commencement of spawning activities of Acipenser sinensis has some selectivity for the rainy day, but shies away from the cloudy day. The dramatic variation of weather type around the initial spawning day may be an inducement to the commencement of spawning activities, and consecutive sunny days in the present spawning area also have the same effect to the commencement of spawning activities. While the average temperature on the initial spawning day in the first and second spawning periods within the present spawning area shows a significant variation, other meteorological elements on the initial spawning day within both historic and present spawning areas do not differ significantly among the first spawning period, the second spawning period and the variation range (extent of date between the early and the late initial spawning days) of the initial spawning days. The variation trend of average air pressure on the initial spawning days in the first and second spawning periods is in the other diection to a certain extent. The sunshine hours, water level and silt content in the present spawning area do not have mutual relationship between each other as those in the historical spawning areas. Meteorological conditions may be an important factor for the commencement of the natural spawning behavior of Acipenser sinensis.