The genetic variability of four fish species (Pimelodus maculatus, Prochilodus lineatus, Salminus brasiliensis and Steindachneridion scripta) collected in the upper Uruguay River basin was analyzed using the

Barley (Hordeum vulgare L.) is widely used for brewing and animal feed. Recently, it has become desirable for human consumption due to its high nutritional significance, specially hull-less or naked barley. There are differences in nutritional and malting characteristics among barley varieties. RAPD procedure is able to separate barley varieties at various similarity levels. The aim of this work was the RAPD analysis of six Brazilian hull-less varieties and seven malting varieties. PCR reactions were performed with eleven random primers. A total of 34 RAPD fragments was obtained with five primers. A dendrogram was constructed based on the Jaccard similarity coefficient. Barley varieties displayed an average similarity coefficient of 0.53. Intravarietal monomorphic fragments allowed differentiation among varieties.

Lophius gastrophysus has important commercial value in Brazil particularly for foreign trade. In this study, we described the optimization of Random Amplified Polymorphic DNA (RAPD) protocol for identification of L. gastrophysus. Different conditions (annealing temperatures, MgCl 2 concentrations, DNA quantity) were tested to find reproducible and adequate profiles. Amplifications performed with primers A01, A02 and A03 generate the best RAPD profiles when the conditions were annealing temperature of 36ºC, 25 ng of DNA quantity and 2.5 mM MgCl 2 . Exact identification of the species and origin of marine products is necessary and RAPD could be used as an accurate, rapid tool to expose commercial fraud.