Biological control of Dolops carvalhoi (Crustacea:Branchiura) in pacu juveniles (Piaractus mesopotamicus)

Abstract

This work evaluated piauçu juveniles (Leporinus macrocephalus) efficiency on the control of Dolops carvalhoi in pacu (Piaractus mesopotamicus) under artificial infestation. A total of 30 fish was equally distributed in six aquaria and acclimated for seven days. After this period, the pacus were unnaturally infested with 20 D. carvalhoi per fish to four days. On the fifth day, each aquarium was added with five uninfected piauçus, and the fish were checked eight times to evaluate the total number of parasites in fish body and aquarium wall. After 24 hours in the aquarium with piauçus, the total number of Dolops was significant lower than in that with only pacus, suggesting that piauçu preyed the parasite. The parasite number was reduced 15 minutes after the addition of piauçus, and after 24 hours, no parasites was found in pacu body and aquarium walls, suggesting that piauçu fingerling may be used to branchiurans infestations in other species of fish.