RESUMO
The DNA barcoding proposes the use of a particular sequence from a single genomic region as the base for an identifying system capable to determine all animal species. This methodology comprises the analysis of a 655 base-pair region from the mithocondrial cytochrome C oxidase gene (COI). Its application in the species identification of fishery products has been very promising. However, in the last years some doubts about its usage have emerged. In this work, we make use of the DNA barcoding for the identification of some of the octopus species with higher commercial interest (Octopus membranaceus, Octopus vulgaris, Octopus aegina, Octopus cyanea) focusing the attention on the reliability and completeness of the available information on the databases. The study looked over 51 individuals apparently belonging to the Octopus genus. For the identification of O.aegina, O.cyanea, O.vulgaris species no particular problems were found. On the other hand, most of the samples of O.membranaceus, though they clearly presented the morphological characteristics of the species, were not identified with the biomolecular analyses.
RESUMO
Isoelectric focusing (IEF) was used to distinguish 4 freshwater fish species that are sold in the European Union under the generic label of "perch": Perca fluviatilis (European perch), Lates niloticus (Nile perch), Stizostedion lucioperca (European pikeperch), and Morone chrysops x saxatilis (Sunshine bass). These species have different commercial values but are easily interchangeable because they are sold already filleted, in view of the numerous bones of the whole fish. IEF of the water-soluble proteins extracted from fish muscle resulted in species-specific patterns. None of the bands was common to all 4 species. Intraspecies polymorphism was low and did not concern the bands identified as characteristic of the species.
