Growth and Morphological Development of Larval and Juvenile Sinibrama taeniatus

Abstract:

Sinibrama taeniatus, a cyprinidae fish belonging to Cultrinae, inhabits only the upper reaches of the Yangtze River, mainly in the Sichuan Province. Due to habitat loss associated with the Three Gorges Project and overfishing, sharp decreases in S. taeniatus populations have been forecast. Surveys of larval and juvenile S. taeniatus were conducted to accumulate developmental data to perfect large-scale artificial breeding technologies and provide a theoretical basis for conservation and recovery of this endemic species. Morphological and anatomic development of larval and juvenile S. taeniatus were with a digital camera system. Newly hatched larvae measured (4.54±0.04) mm at (25.0±0.5)℃. The volume of yolk sacs was (0.26±0.01) mm3, the anterior portion of which was oval and the posterior portion of which was rod-shaped. The development of yolk sac larvae from hatching to yolk absorption took approximately 8 days and the special growth rate of total length was 5.99%. During that period, larvae started feeding on the third day and the mixed nutrition stage lasted 5 days. The relationship between yolk sac volume (V) and age (D) can be expressed as V = −0.0049 D3 + 0.0369 D2 − 0.1333 D + 0.2583 (R2＝0.9947). Late larvae with disappeared yolk sacs completely relied on exogenous material to obtain energy until scales appeared. This developmental stage lasted 25 days and the special growth rate of total length was 2.16%. During the juvenile period, scale development lasted 53 days, and the special growth rate of total length was 0.90%. The relation between total length (TL) and D of larval and juvenile S. taeniatus can be described by TL = −7 × 10−7 D3 −0.0011 D2 + 0.2820 D + 4.7083 (R2＝0.9957).