MORPHOLOGICAL DEVELOPMENT AND ALLOMETRIC GROWTH PATTERN OF KONOSIRUS PUNCTATUS AT LARVAE AND JUVENILE STAGES

This study investigated the morphological development and allometric growth pattern in early life cycle of Konosirus punctatus and illustrated their crucial ecological meanings for survival. Results showed that the average total length of larvae fish was (3.18±0.52) mm with water temperature at (21.5±0.5)℃. The morphological development of K. punctatus was divided into larvae stage (0—43 day age, from hatching to keeled scales appearing) and fry stage (44—55 day age, from keeled scales appearing to scales covering the body). Morphological changes and organ diffe-rentiations mainly occurred in the larval stage. Key morphological characteristics including rostrum length, trunk length, intestinal length, pectoral length and pelvic fin length exhibited allometric growth patterns, in which the growth infle-xion point were 42 day age (TL: 25.47 mm), 24 day age (TL: 15.57 mm), 31 day age (TL: 21.41 mm), 41 day age (TL: 25.47 mm), 42 day age (26.41 mm), respectively. The growth rate in rostrum length and pectoral length changed from the positive allometry (before inflexion point) to the same rate (after inflexion point); the growth rate in pelvic fin length changed from the positive allometry to the negative allometry. These variations could enhance the capacities of breathing, feeding and escaping. The growth rate in intestinal length changed from negative allometry to the same rate, which is related to the dietary conversion of K. punctatus. To adapt to the complex environments, key organs involved in growth and survival were preferentially developed at the early stage, which facilitated the survival rate of K. punctatus. All the findings provide a fundamental evidence for artificial breeding and seedling cultivation in the future.