Lignobrycon myersi is a threatened freshwater fish species and endemic of a few coastal rivers in northeastern Brazil. Even though the Brazilian laws prohibit the fisheries of threatened species, L. myersi is occasionally found in street markets, being highly appreciated by local population. In order to provide a reliable DNA barcode dataset for L. myersi, we compared mitochondrial sequences of cytochrome c oxidase subunit I (COI) from fresh, frozen, and salt-preserved specimens. Phylogenetically related species (Triportheus spp.) and other fish species (Astyanax fasciatus) commonly mixed with L. myersi in street markets were also included to test the efficiency of molecular identification. In spite of the differences in conservation processes and advanced deterioration of some commercial samples, high-quality COI sequences were obtained and effective in discriminating L. myersi specimens. In addition, while populations from Contas and Almada River basins seem to comprise a single evolutionary lineage, the specimens from Cachoeira River were genetically differentiated, indicating population structuring. Therefore, DNA barcoding has proved to be useful to trace the illegal trading of L. myersi and to manage threatened populations, which should focus on conservation of distinct genetic stocks and mitigation on human impacts along their range.

Araucaria angustifolia is endemic to southern Brazil. Known as Brazilian pine, A. angustifolia is the only native conifer species with economic and social relevance in this country. Due to massive exploitation, it has suffered a significant population decline and currently is classified as critically endangered. This encouraged the scientific community to investigate genetic features in Brazilian pine to increase resources for management and preservation. In this work, RNA-Seq data was used to determine the complete nucleotide sequence of the A. angustifolia chloroplast genome (cpDNA). The cpDNA is 146,203 bp in length and contains 122 genes, including 80 protein-coding genes, 5 ribosomal RNA genes, and 37 tRNA genes. Coding regions comprise 45.02%, 4.96% correspond to rRNAs and tRNAs, and 50.02% of the genome encompasses non-coding regions. Genes found in the inverted repeat (IR) are present as single copy, with exception of the rrn5 and trnI-CAU loci. The typical LSC, SSC, IRa and IRb organization reported in several land-plant groups is not present in A. angustifolia cpDNA. Phylogenetic analyses using Bayesian and Maximum Likelihood methods clustered A. angustifolia in the Araucariaceae family, with A. heterophylla and A. columnaris as congeneric species. The screening of A. angustifolia cpDNA reveled 100 SSRs, 14 of them corresponding to tetrapolymer loci.

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Parrotfishes (Labridae, Scarinae) comprise a large marine fish group of difficult identification, particularly during juvenile phase when the typical morphology and coloration of adults are absent. Therefore, the goal of this study was to test cytogenetic markers and DNA barcoding in the identification of bucktooth parrtotfish Sparisoma radians from the northeastern coast of Brazil. Sequencing of cytochrome c oxidase subunit I (COI) confirmed all studied samples as S. radians, and all showed high similarity (99–100%) with Caribbean populations. The karyotype of this species was divergent from most marine Perciformes, being composed of 2n = 46 chromosomes. These consisted of a large number of metacentric and submetacentric pairs with small amounts of heterochromatin and GC-rich single nucleolar organizer regions (NORs) not syntenic to 5S rDNA clusters. These are the first data about DNA barcoding in parrotfish from the Brazilian province and the first refined chromosomal analysis in Scarinae, providing useful data to a reliable genetic identification of S. radians.