Ferramentas moleculares aplicadas na identificação do hidróide invasor Cordylophora caspia (Pallas, 1771)

Abstract

The establishment of invasive species is one of the main threats to the planet’s biodiversity due to their great potential to cause economic and ecological impacts. Considering aquatic species, a particularly problematic group is the one capable of fouling, as they can form biofilms (microfouling) or colonies (macrofouling) that quickly disrupt the communities composition where they settle, competing for substrate, releasing toxic compounds or even introducing associated diseases and pathogens alien in that ecosystem. These species can affect hydroelectric plants and water treatment plants, causing several economic losses related to energy generation and water capture. Cordylophora caspia (Pallas, 1771) is considered an invasive species, as an euryhaline hydroid, native to the Ponto-Caspian region and nowadays has a wide global distribution. In Brazil, it is relatively underreported and in the Minas Gerais state, was only reported at the hydroelectric plant of Funil and São Simão. A way to avoid or control recent invasions is with the rapid detection of the alien species, before it becomes densely established in a new location. Since visual identification demands specialized professionals, once Cordylophora can be easily mistaken for an algae or macrophyte for people who do not know it, an alternative would be the use of molecular identification techniques based on DNA barcoding. This work aimed to test molecular tools already described in the literature to be used in the identification of Cordylophora caspia. Our results indicated that primers described in the literature, designed based on sequences from phylogenetic related species, to amplify fragments of the main genes used in DNA barcoding (COI, 16S and 18S) did not allow to consistently identificate the specific sequences when used in DNA isolated from C. caspia hydrants and gonophores. Besides, this work presented a new record of the recently discovered population at the Volta Grande hydroelectric plant, in Grande river, on the border of Minas Gerais and São Paulo.