Allometric growth pattern and point of no return for starvation of Furong crucian carp （Carassius auratus Furong carp ♀×Cyprinus carpio red crucian carp ♂）

【Objective】To provide a reference for the breeding of Furong crucian carp larvae（Carassius auratus Furong carp ♀×Cyprinus carpio red crucian carp ♂ ），the allometric growth pattern and starvation tolerance of Furong crucian carp have been explored.【Method】In this paper，the morphological length of function organs （total length，eye diameter，sount，head，body height，trunk，dorsal fin，anal fin，caudal fin）of Furong crucian carp larvae were measured conti-nuously to study its allometric growth pattern and initial feeding rate under the state of starvation.【Result】The results showed that Furong crucian carp larvae opened mouths for feeding at 3 days of age，and the yolk sac disappeared completely at 9 days of age. The relative ratio of mixed nutrition stage of larvae was 2.0，which indicated that Furong crucian carp larvae had strong starvation tolerance. Furong crucian carp larvea preferentially developed organs related to digestion，feeding，breathing，and swimming balance such as body height，snout，head，dorsal and anal fins to adapt to the early artificial breeding environment. The growth inflection points in the allometric growth pattern of Furong crucian carp mainly occurred in the flexion and post-flexion stages. Eye diameter，snout，head，body height，trunk，dorsal fin， anal fin and caudal fin appeared growth inflection points at 16 days of age（total length 14.00 mm），12 days of age（total length 11.42 mm），14 days of age（total length 11.96 mm），12 days of age（total length 11.38 mm），16 days of age（total length 13.96 mm），14 days of age （total length 12.10 mm），15 days of age （total length 13.20 mm）and 23 days of age （total length 17.21 mm）respectively. Relative to the total length，body height was positive allometric growth before the growth inflection point，and was isokinetic growth after the growth inflection point. The snout，dorsal fin and anal fin were all positive allometric growth before and after the growth inflection point. The trunk was negative allometric growth before and after the growth inflection point. Head and eye diameter changed from isokinetic growth to positive allometric growth. Growth inflection points were not observed for pectoral fins，body length and caudal length. Furong crucian carp starvation experiment found that the initial feeding rate was appeared at 3 days of age and the rate was only 10.0%. The initial feeding rate reached the highest（90.0%）at 8 days of age，and then rapidly decreased to 45.0% at 10 days of age， indica-ting that the point of no return（PNR）was reached.【Conclusion】The growth inflection points of various organs of Furong crucian carp larvae mainly appear in 12-16 days of age. The organs related to feeding，digestion，respiratory system and swimming balance，such as body height，snout，head，dorsal fin and anal fin are preferentially developed in Furong crucian carp larvae. The Furong crucian carp larvae open mouths for feeding at 3 days of age，PNR is 10 days of age，and the relative ratio of mixed nutrient stage is 2.0，indicating that the larvae have strong starvation tolerance. Therefore，under the condition of water temperature of（19.90±2.83） ℃，3-4 days of age is the best time to cultivate Furong crucian carp in the pond after stripping of fish eggs，and it should not be later than 9 days of age at the latest.