LAUSR

Abstract Brycon orbignyanus is a neotropical fish found in several South American countries. This species has high ecological importance and is included in the list of fish threatened with extinction. In this study, we report the development and characterisation of 12 microsatellite primers of B. orbignyanus for future genetic studies. Screening of the 12 markers in a sample of 35 individuals identified seven polymorphic loci and 22 alleles, with one to three alleles per locus. The polymorphic information content ranged from 0.054 to 0.542, with four loci showing significant deviation from Hardy–Weinberg equilibrium. Two loci possessed null alleles. Cross-species amplification tests in two closely related species showed that 11 loci are transferrable to Brycon gouldingi (B. gouldingi) and nine are transferrable to B. falcatus. The microsatellite primers designed may be used for genetic variability and population structure studies in wild populations, fish farms and restocking programmes of B. orbignyanus and the two related species.