Ontogenetic development in the morphology and behavior of loach （Misgurnus anguillicaudatus） during early life stages

• Published in: 中国海洋湖沼学报：英文版 2014 (5), p.973-981
• Main Author: 高雷 段明 程飞 谢松光
• Format: Article
• Language: English
• Subjects: 个体; 形态特征; 早期幼鱼; 泥鳅; 生产过程; 生命; 育发; 行为特征
• ISSN: 0254-4059; 1993-5005

Loach （Misgurnus anguillicaudatus） is a commercially important fish in China and an ideal aquaculture species. However, culturists experience high larval and juvenile mortality during mass production. To provide insight into ways to improve larviculture techniques, we describe the morphological characteristics and behavior of loach during the larval and early juvenile stages. Yolksae larvae ranged from 2.8 to 4.0 mm body length （BL） between days 0 to 4; preflexion larvae ranged from 3.6 to 5.5 mm BL between days 4 to 6; flexion larvae ranged from 4.8 to 8.1 mm BL between days 5 and 14; and post-flexion larvae ranged from 7. l to 15.7 mm BL between days 11 to 27; the minimum length and age of juveniles was 14.1 mm BL and 23 d, respectively. Loach are demersal from hatch through to the early juvenile stages. A suite of morphological characteristics （e.g., external gill filament and ventral mouth opening） and behavioral traits have developed to adapt to demersal living. We observed positive allometric growth in eye diameter, head length, head height, and pectoral fin length during the early larval stages, reflecting the priorities in the development of the organs essential for survival. Our results provide a basis for developing techniques to improve the survival of larval and juvenile loach during mass production.