Detecção da Branquinha Cascuda (Psectrogaster rutiloides Kner, 1858) em DNA Ambiental

Abstract

The seasonal hydrological changes that occur in the Amazon basin are part of the habitat of the native ichthyofauna, these geographical alterations are characterized as a flood pulse, and allow a greater interaction of fish species with the environment. Identifying the location of these shoals and monitoring the range of occurrence of many species currently depends on methods that include the collection of genetic material from fish carcass tissues, a method considered invasive, and which depends on capture and often on the consequent mortality. of individuals. In this sense, a new technique has been applied in the neotropical region and used as a non- invasive method, the environmental DNA (aDNA), which can serve as an aid in the monitoring of species, molecular identification, among other problems. For this reason, the present study aimed to detect the fish species Psectrogaster rutiloides (Kner, 1858) using aDNA present in four floodplain lakes in Central Amazonia (Ressaca, Piranha, Cacau and Preto). The present study aimed to carry out an in vitro test of the specific detection system for Psectrogaster rutiloides (Kner, 1858) and related species (Psectrogaster essequibensis, Psectrogaster amazonica and Psectrogaster ciliata), verifying whether the target species can be detected (test in vivo) both in the flood and in the dry season in DNAa of floodplain lakes connected and not connected with the Solimões River. To obtain results, the extraction of DNAa collected in water samples from the sampled lakes and DNAg from individuals of the target species and related species were performed, then quantification and amplification were performed in conventional PCR and real-time PCR, using the detection system developed for the target species. Although some species were detected in conventional PCR, these species were not detected in hydrolysis probe qPCR assay, which confirms the specificity of the species-specific detection system. It was possible to detect the presence of the Psectrogaster rutiloides species in aDNA, both in the dry season and in the flood season in all four lakes and in the analyzed annual periods. These elements, when well developed, can serve as an efficient detection system, being a non-invasive alternative for future scientific research aimed at detecting and/or monitoring species in the environment.