南海北部陆坡水域尾明角灯鱼生物学特征的初步研究

尾明角灯鱼Ceratoscopelus warmingii是南海北部陆坡水域中层鱼类的重要种类之一,本试验中根据2015年6月南海北部陆坡水域综合调查中的中层拖网数据,对尾明角灯鱼生物学特征及分布进行了初步研究。结果表明:夏季南海北部陆坡水域尾明角灯鱼的体长范围为30~64 mm,体长由3个股群组成,其体长平均值分别为(37.52±2.39)、(44.62±2.84)、(49.80±3.17)mm,其体长与体质量关系式为W=8.418×10~(-6)L~(3.0985);性腺成熟度以Ⅱ期、Ⅲ期居多,50%性腺发育为Ⅱ期及以上的尾明角灯鱼体长为42.54mm,雌、雄比为1∶0.7,较大个体中雌性居多;夜间其平均摄食等级随时间的延长逐渐增加,20:00、22:00、4:00时尾明角灯鱼的平均摄食等级分别为0.82、1.58、2.53;本次调查白天在600 m以浅水层多未捕获尾明角灯鱼,傍晚开始捕获少量样品,夜间在上层捕获的量较大,该现象反映了南海北部陆坡水域尾明角灯鱼昼夜垂直移动的习性,同时佐证了该鱼白天多分布于700 m以深水域的相关研究结果。本研究结果可为南海北部陆坡水域尾明角灯鱼的进一步研究提供基础参数及资料。

Biology of lanternfish Ceratoscopelus warmingii in waters of the northern slope in South China Sea

The distribution and biological characteristics of lanternfish Ceratoscopelus warmingii as an important species were studied based on the catches of mesopelagic fish survey conducted in the northern slope in the South China Sea during June of 2015 . It was found that the lanternfish had body length from 30 mm to 64 mm and three cohorts with overlapping body length, (37. 52±2. 39), (44. 62±2. 84) and (49. 80±3. 17)mm. The relationship between body length and body weight was expressed as W=8. 418×10-6L3.0985. Over half of the lanternfish with body length of 42 . 54 mm collected in June had gonads which developed into maturity at stageⅡand stageⅢ, with sex ratio of 1:0. 7 ( female :male), smaller in male than in female. The average degree of stomach fullness ( ADSF) of the lanternfish was found to be increased with time during night,with ADSF of 0. 82 at 20:00, 1. 58 at 22:00, and 2. 53 at 4:00. No lanternfish were collected at over 600 m depth during the daytime. However, a few lanternfish were caught during evening, and more fish were collected at night at over 650 m depth except one sta-tion,indicating that the diel vertical migration is one of important feature of lanternfish and that agrees with the other research results during day time most species aggregated in water deeper than 700 m depth. The findings will help to analyze the biology and distribution of the lanternfish in waters of the northern slope in South China Sea.