莱州湾口虾蛄的生物学特征与时空分布

Fishery biology characteristics,temporal and spatial distribution of Oratosquilla oratoria in Laizhou Bay,Bohai Sea

根据2011年5月-2012年4月期间进行的9个航次（月份）的底拖网采样,研究了莱州湾水域口虾蛄的生物学特征、资源密度的时空分布以及环境因子的影响,以期为口虾蛄资源的利用和保护提供理论依据。结果显示,口虾蛄资源密度（生物量和个体数）月间变化为8月〉7月〉9月〉10月〉5月〉11月〉6月〉4月〉3月。口虾蛄体长范围为41~171 mm,平均体长5月最低（102 mm）,7月最高（118 mm）;体重范围为0.30~68.00 g,平均体重5月最低（13.64g）,11月最高（17.67g）。雌、雄个体肥满度均以10月最高,分别为1.49和1.56,肥满度的月间变化趋势为5-7月下降,8-10月上升,11月以后再次下降。肥满度的性别差异不显著（P〉0.05）。除5月雌体数量高于雄体外,其他月份雌、雄比均小于1。口虾蛄于5-7月（产卵期）主要分布在黄河口、龙口近岸等浅水区,8月开始向深水区迁移,9月至翌年3月主要分布在深水区,4月开始返回近岸水域。Pearson相关分析表明,口虾蛄个体数密度与海表温度相关性最高,其次是盐度、水深、浮游动物及其他渔获生物量,与底层溶解氧、浮游植物的相关性最低;口虾蛄平均个体重量在8-9月与水深分别呈极显著相关（P〈0.01）和显著相关（P〈0.05）关系,与其他渔获生物量在2011年7-8月及2012年4月呈显著相关（P〈0.05）,与其它环境因子的相关性在各月份均不显著（P〉0.05）。

M onthly variation of biology characteristics,density and its spatial distribution of O. oratoria in Laizhou Bay,together with the influence of environmental factors,were analyzed according to the bottom trawl data of 9 surveys from M ay 2011 to April 2012,in order to provide theoretical basis for utilizing and protecting the resources of O. oratoria. The monthly variation of density（ both biomass and individual number） was August July September October M ay November June April M arch. The body length of O. oratoria was 41- 171 mm and the average body length was the lowest in M ay by 102 mm and the highest in July by 118 mm. The body weight of O. oratoria was 0. 30- 68. 00 g and the average body weight was the lowest in M ay by 13. 64 g and the highest in July by 17. 67 g. The individual fatness coefficient was the highest in October both for the female（ 1. 49） and the male（ 1. 56）. The trend of the monthly change of fatness coefficient was on the decline in M ay- July,on the rise in August-October and on the decline after November again. The difference of fatness coefficient was not significant（ P 0. 05）between the male and the female. The ratio of the female to the male was less than 1. 0 in every month except in M ay. O. oratoria was mainly distributed in shallowwaters in spawning seasons（ M ay- July）,such as the YellowRiver estuary and they started to migrate to profundal zone in August and inhabited the areas from September to next M arch,then returned to shallowwaters in April. Pearson correlation analysis indicated that environmental factor that best matched the density of O. oratoria was sea surface temperature（ SST）,then the salinity（ Sal）,the water depth（ Dep）,the zooplankton and other fishing catch biomass. The correlation coefficient was the lowest between the density of O. oratoria with dissolved oxygen（ DO） and phytoplankton. The correlation between the average individual weight of O. oratoria with environmental factors was not significant（ P 0. 05）,except with the Dep in August（ P 0. 01）,September（ P 0. 05）and with other fishing catch biomass in July,August and next April（ P 0. 01）.