A thermosolar nursery for tilapia (Oreochromis niloticus L.)

摘要

A thermosolar nursery development for rural producers was built and tested in three different operational conditions. The system consisted of a solar collector connected to a coiled heat exchanger inside a fish culture tank. A pump activated by two thermostats was used to circulate water throughout the heating circuit. A short-term pilot test was performed to probe the maximum heating of the system. Two more tests (Tests A and B) were carried out to evaluate the effect of heat insulation covering on the thermosolar fish tank. A student´s t-test was performed to assess the statistical difference in temperature and fish growth between the thermosolar tank and the control tank (which lacked thermal heating). The maximum temperature achieved by the system was 37.94°C. In Test A, the mean temperature of the thermosolar and control tanks after 49 days were 27.50 and 25.02°C, respectively. In Test B, the mean temperature after 38 days was 25.84 and 20.06°C, respectively. Differences in the weight and length of the fish were found. On test B, daily growth rate, survival and total biomass were higher in the thermosolar system than in control. The results suggest that the system can improve the growth performance and survival of the fingerlings.