Isolation and characterization of microsatellites loci for “piramutaba” (Brachyplatystoma vaillantii, Siluriformes: Pimelodidae), one of the commercially most important migratory catfishes in the Amazon Basin

Abstract

The piramutaba (Brachyplatystoma vaillantii) is one of the largest and most important migratory catfishes of the Amazon Basin. Due to its historical commercial importance, this species is now considered overfished. Fifteen polymorphic microsatellite markers were characterized in order to be used as tools to address aspects of the biology and conservation of this species. The number of alleles varied from 4 to 26 per locus, with an average of 11.33 alleles per locus, in 36-48 individuals tested. The observed and expected heterozygosities varied from 0.30176 to 0.95281, and from 0.25532 to 0.97778, respectively. All the microsatellites were found to be in HardyWeinberg equilibrium, and no linkage disequilibrium was observed. The transferability of these markers was tested in others Brachyplatystoma with seven to 12 loci being polymorphic per species. The results indicate that these markers are adequate for genetic studies applied to the management and conservation of the piramutaba, and others Brachyplatystoma species.

Goliath catfish spawning in the far western Amazon confirmed by the distribution of mature adults, drifting larvae and migrating juveniles

“…The geographical genetics of three goliath catfish species have been studied, but only B. platynemum presented clear population segregation for the Amazon River mainstem and Madeira River 33 , whereas B. vaillantii showed no genetic segregation 46 47 . Genetic studies of B. rousseauxii presented mixed results but indicated a relatively homogenous population in the Amazon Basin, although homing behavior could not be totally excluded 48 49 .…”

A Multilocus Approach to Understanding Historical and Contemporary Demography of the Keystone Floodplain Species Colossoma macropomum (Teleostei: Characiformes)

“…A compilation of average H E values for microsatelite loci obtained from the literature for exploited Amazonian migratory fish shows average H E values ranging from 0.50 of Brachyplatystoma platynemum (Ochoa et al, 2015 ), to 0.87 of Semaprochilodus insignis (Passos et al, 2010 ). Between this minimum and maximum, one can observe H E = 0.61 of Brachyplatystoma rousseauxii (Batista, 2010 ), H E = 0.75 of Brachyplatystoma vaillantii (Rodrigues et al, 2009 ), and H E = 0.83 of Brycon amazonicus (Oliveira et al, 2018 ). An average of these values (mean H E = 0.72) is not in agreement with DeWoody and Avise ( 2000 ), who report an average H E = 0.54 for freshwater fishes.…”