Journal of Zhejiang Agricultural Sciences ›› 2026, Vol. 67 ›› Issue (8): 1855-1859.DOI: 10.16178/j.issn.0528-9017.20250811

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Effect of breeding density on the temporary breeding of Procambarus clarkii juveniles

CHENG Shun1(), ZHANG Peixin2, JIANG Wenping1, CHI Meili1, ZHENG Jianbo1, LIU Shili1, ZHU Chao1, XIN Jianmei1, LI Fei1()   

  1. 1.Zhejiang Institute of Freshwater Fisheries,Key Laboratory of Healthy Freshwater Aquaculture,Ministry of Agriculture and Rural Affairs,Key Laboratory of Freshwater Aquaculture Genetics and Breeding,Huzhou 313001,Zhejiang
    2.Zhejiang Hechugui Ecological Farm Co. ,Ltd. ,Huzhou 313215,Zhejiang
  • Received:2025-11-03 Online:2026-08-11 Published:2026-08-20
  • Contact: LI Fei

Abstract:

Procambarus clarkii is one of the important aquaculture species in China,and releasing large-sized seedlings in March-April is currently a relatively stable farming model. To address the supply issue of large-sized seedlings,studying the temporary breeding of P. clarkii juveniles has practical significance. This study set up four treatment groups(100,200,300,and 400 individuals per square meter)to investigate the effects of different breeding densities on juveniles. After 21 days of breeding,the survival rate and weight gain rate of each group were recorded. The molting,feeding,and fighting behaviors of P. clarkii juveniles were observed,and the activities of trypsin and α-amylase as well as ecdysteroid content were measured. The results showed that treatment 1(100 individuals per square meter)achieved a survival rate of 85.71%,significantly(p<0.05)higher than the other treatments. Treatment 4(400 individuals per square meter)exhibited a weight gain rate of only 35.34%,significantly lower than the other treatments. In treatment 1,juveniles displayed stable feeding,minimal fighting,fewer molts,and lower ecdysteroid content. Treatment 4 juveniles frequently engaged in food competition and fighting,experienced more molts,and higher ecdysteroid content. Treatment 1 showed higher trypsin and α-amylase activity,while treatment 4 exhibited lower activity for these two enzymes. It is speculated that lower breeding density may help reduce food competition and fighting frequency among juveniles,thereby improving their digestive absorption capacity and survival rate. High breeding density may stimulate food competition and fighting among juveniles,potentially promote molting,but could lead to the predation of faster-growing molting juveniles by conspecifics,resulting in reduced survival rate and weight gain rate. In summary,it is recommended that the temporary breeding density for P. clarkii juveniles be set at 100 individuals per square meter to maintain higher survival rate and eight gain rate.

Key words: Procambarus clarkii, density, temporary breeding

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