In recent decades, Brazilian hydroelectric reservoirs have been stocked with hundreds of millions of juvenile migratory fish, but almost no research on stocking has been conducted. In order to study stocking it is essential to tag the fish to be stocked. In this investigation we determined handling-induced mortality, tag retention rate, and absolute growth rate of hatchery-reared juvenile curimbatá (Prochilodus lineatus) tagged with coded wire tags (CWT), a tag widely used on stocked fish. We injected CWT into the dorsal musculature just below the first dorsal fin ray. Despite the need for frequent tag injector maintenance, this tagging location proved to be suitable for tagging juvenile curimbatá. We found no short-term mortality of juvenile curimbatá handled for CWT tagging, high retention rate for CWT (≥ 98.2%) even after 174 d of tagging, and no influence on absolute growth rate by CWT. We conclude that CWT is effective at tagging juvenile curimbatá, and we expect that it will also be effective for many other Brazilian fish species used for stocking.
Neotropical fish; Passive tag; Stocking; Tag retention; Tagging mortality
