北部湾春季多齿蛇鲻生物学特征及其年际变化

Biological characteristics and inter-annual changes of Saurida tumbil in spring in the Beibu Gulf, South China Sea

中文关键词: 北部湾  多齿蛇鲻  生物学特征  50%性成熟体长  肥满度  年际变化

英文关键词: Beibu Gulf  Saurida tumbil  Biological characteristics  Length at 50% maturity  Fatness  Inter-annual change

中文摘要:

      根据北部湾渔港采样及海上调查生物学测定与数据分析，研究了北部湾多齿蛇鲻(Saurida tumbil)春季生物学特征及其年际变化。结果显示，2008~2018年春季，多齿蛇鲻个体呈小型化趋势，各年度平均体长范围为15.8~16.9 cm，平均体质量范围为48.8~77.5 g，2018年的平均体长和平均体质量比2008年分别降低了6.5%和34.5%。体长–体质量关系式中的异速生长参数b的范围为3.03~3.42，表明春季群体主要呈正异速生长状态(b>3)。性成熟体长年际变化分析表明，北部湾多齿蛇鲻存在性成熟提前的现象，雌性群体50%性成熟体长从2008年(19.0 cm)至2018年(16.6 cm)整体呈减小趋势，10年间减小比例为12.6%，其中，2011~2015年海上采样的样品对比显示，50%性成熟体长减小比例为3.8%。2008~2018年北部湾多齿蛇鲻的肥满度整体呈下降趋势，均值变化范围为1.09~1.29，渔港采样样品和海上采样样品的肥满度年际变化皆呈下降趋势。

英文摘要:

      Using data from the spring fishing port samples and bottom trawl surveys in the Beibu Gulf, the biological characteristics and inter-annual changes of Saurida tumbil were investigated. The population structure of S. tumbil in the Beibu Gulf had a miniaturization trend - the average standard length (SL) and body weight (BW) decreased from 2008 to 2018, with ranges of 15.8~16.9 cm and 48.8~77.5 g, respectively. There were also temporal variations in SL and BW; the average values decreased by 6.5% and 34.5% from 2008 to 2018, respectively. The range of the allometric parameter b was 3.03~3.42, indicating that S. tumbil had positive allometric growth (b>3) in the Beibu Gulf in spring. Analysis of the inter-annual change in length at 50% maturity (L50) in females showed that the S. tumbil population maturated before the L50, decreasing 12.6% from 2008 (19.0 cm) to 2018 (16.6 cm). Compared to 2011 (18.6 cm), the 2015 female L50 reduced by 3.8% (17.9 cm). Fatness also declined from 2008 to 2018 (range: 1.09~1.29), as evidenced by consistent downward trends in the fatness samples from both fishing methods. However, fatness had an overall increasing trend with increasing SL.