Relations between morphological traits and body weight of shortbelly eel, Dysomma anguillare (Actinopterygii: Anguilliformes: Synaphobranchidae), from coastal waters of Zhoushan, East China Sea, determined by multivariate analyses

Abstract

The shortbelly eel, Dysomma anguillare Barnard, 1923, is an essential component in the food chain of the marine ecosystem and plays an important role in nearshore fisheriesand biodiversity in the East China Sea. In order to provide theoretical support for fisher resource assessment and sustainable utilization of D. anguillare, an important bycatch in the offshore area of China, the relations be- tween morphological traits and body weight were investigated based on the measurement of 28 metric traits for the firsttime. The cor- relation analysis showed that 25 morphological traits were significantly(P < 0.05) correlated with the logarithm of body weight (lgX ), in which the correlation coefficientof the total length (X ) was the largest with the extremely high significance(P < 0.01). The optimum multiple regression equation of morphological traits was constructed after deleting redundant independent variables: lgX = 0.367 + 0.003X + 0.010X – 0.010X + 0.011X + 0.042X + 0.006X + 0.024X – 0.004X . The total length (X ) had the highest positive direct relation with lgX (0.699), which was in accordance with the results of determinate coefficientanalysis, while the indirect effect of body height (X ) through lower jaw length (X ) to lgX was the greatest. The gray correlation analysis indicated that body length (X ) and distance from snout to dorsal finorigin (X ) were the most closely related to body weight. The comprehensive comparison showed that X , X , and X should be used as the ideal morphometric traits for measuring the body weight of D. anguillare, and the conclusions obtained from this study will provide valuable references for fisheryresource management of this commercial fishspecies.