Effects of different fertilization patterns on the dietary composition of Procambarus clarkii in a rice-crayfish coculture system

Abstract

As an omnivorous species, crayfish (Procambarus clarkii) have varying feeding habits in different environments. However, little is known about the diet of crayfish under different fertilization patterns in rice-crayfish cocultures. In this study, we investigated the effect of fertilization on the growth performance, dietary composition and isotopic niche of crayfish in a rice-crayfish coculture system. Four experimental treatments were established: no fertilizer (CK), slow-release fertilizer (HS), crayfish rice fertilizer (XD) and compound fertilizer (FH). The results showed that HS and FH could significantly promote crayfish growth, and the growth of crayfish treated with HS was the best. Fertilization patterns had significant effects on the dietary composition of crayfish. The food source of unfertilized crayfish was relatively balanced. However, in the HS, XD and FH treatments, particulate organic matter increased with contribution rates of 34.04%, 56.89% and 42.86%, respectively. In addition, the artificial feed intake of crayfish in the FH group was the lowest. The isotopic niche revealed that crayfish in the HS group significantly increased in the direction of the δ15N axis. Based on routine economic indicators, slow-release fertilizer was suitable for the rice-crayfish coculture system. These findings could provide scientific guidance for the selection of fertilization modes in rice-crayfish coculture systems and the exploration of healthy crayfish culture models.

Keywords

• Procambarus clarkii
• Diet
• Rice-crayfish coculture
• Fertilization
• Stable isotope