1.Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences，Wuxi 214081, China; 2.College of Wuxi Fisheries, Nanjing Agricultural University, Wuxi 214081, China
Abstract: Juvenile and adult red swamp crayfish (Procambarusclarkii) were reared in tanks (60 cm × 40 cm × 40 cm) at a rate of 20 individuals per tank and fed 5 aquatic plant species (Alternantheraphiloxeroides,Eichhorniacrassipes, Lesser duckweedLemnaminor,Elodeanuttallii, and pondweedVallisnerianatans) to evaluate food items and changes in food filling in stomach and intestines during day and night. In addition, the growth was compared in th crayfish reared in a paddyfield and fed three diets (crayfish feedstuff with 30% protein, aquatic grasses and trash fish). The food in the intestine of the juvenile crayfish was found to be primarily comprised of zooplankton and phytoplankton. The adult crayfish was shown to have lower food preference, almost all of edible aquatic animals and plants, organic detritus, and artificial feed available in waters being consumed, and aquatic plants constituting their main food due to wide distribution, and easy ingesting. The feeding rhythm was observed during day and night in the crayfish culture pond, the two peaks at 8:00-10:00 and 19:00-22:00. There was significantly better growth in the adult crayfish fedElodeanuttallii, Lesser duckweed andVallisnerianatansthan that in the crayfish fedAlternantheraphiloxeroidesandEichharniacrassipes(P<0.01). However, there was no significant difference in growth in the crayfish fedElodeanuttallii, Lesser duckweed andVallisnerianatans(P>0.05), even though the crayfish fed Lesser duckweed had slightly better growth than the crayfish fedElodeanuttallii, andVallisnerianatansdid. There was significant difference in daily weight gain rate in the juvenile crayfish fed lesser duckweed,Elodeanuttallii,Vallisnerianatans,Alternantheraphiloxeroides,Eichhorniacrassipes(P<0.05). In the rice field, however, the crayfish fed trash fish was shown to have much better growth than that the crayfish fed pelleted food, and pelleted feedstuff combined with aquatic plants.
2012, Vol. 27 
