Microsatellites for the Amazonian Fish Hypophthalmus marginatus

We isolated 41 and characterized 17 microsatellite loci for evaluating the genetic structure of the Amazonian fish Hypophthalmus marginatus, from the Tocantins and Araguaia River in the Eastern Amazonia. Of the 17 selected microsatellite sequences, 15 were dinucleotide repeats, 9 of which were perfect (5–31 repetitions) and 6 were composite motifs. Among these 17 microsatellites, only two were polymorphic. The average number of alleles (Na) observed in the five examined populations ranged from 3.5 to 4.5, while the average observed heterozygosity (Ho) ranged from 0.3 to 0.6. The allelic frequency was less homogeneous at the locus Hm 5 than that for the Hm 13. Genetic diversity was measured in three upstream and two downstream populations under the influence of the Tucuruí Hydroelectric Dam. Our findings provide evidence for low levels of genetic diversity in H. marginatus of the Tocantis basin possibility related to the Dam construction. The Fst and Rst analysis fits well with migratory characteristics of H. marginatus, suggesting the existence of a gene flow mainly in the upstream or downstream directions. To test the hypothesis that the Dam was responsible for the detected reduction on this species genetic diversity, a large number of genetic markers are recommended, covering geographic distribution range of the fish species

Discovery or Extinction of New Scleroderma Species in Amazonia?

The Amazon Forest is a hotspot of biodiversity harboring an unknown number of undescribed taxa. Inventory studies are urgent, mainly in the areas most endangered by human activities such as extensive dam construction, where species could be in risk of extinction before being described and named. In 2015, intensive studies performed in a few locations in the Brazilian Amazon rainforest revealed three new species of the genus Scleroderma: S. anomalosporum, S. camassuense and S. duckei. The two first species were located in one of the many areas flooded by construction of hydroelectric dams throughout the Amazon; and the third in the Reserva Florestal Adolpho Ducke, a protected reverse by the INPA. The species were identified through morphology and molecular analyses of barcoding sequences (Internal Transcribed Spacer nrDNA). Scleroderma anomalosporum is characterized mainly by the smooth spores under LM in mature basidiomata (under SEM with small, unevenly distributed granules, a characteristic not observed in other species of the genus), the large size of the basidiomata, up to 120 mm diameter, and the stelliform dehiscence; S. camassuense mainly by the irregular to stellate dehiscence, the subreticulated spores and the bright sulfur-yellow colour, and Scleroderma duckei mainly by the verrucose exoperidium, stelliform dehiscence, and verrucose spores. Description, illustration and affinities with other species of the genus are provided. IntroductionWe are grateful to the Conselho Nacional de Desenvolvimento CientõÂfico e TecnoloÂgico (CNPqÐBrazil, process PVE/407474/2013-7 and PPBio/457476/2012-5), and FundacËão de Amparo à Pesquisas do Estado do Amazonas (FAPEAM-Brazil) for the financial support; as well as to Centro de Estudos Integrados da Biodiversidade AmazoÃnica (INCT-CENBAM).Peer reviewe

Phylogenetic tree obtained from Bayesian analysis of <i>Scleroderma</i> species.

<p>Numbers above branches are parsimony bootstrap (MP-BS), maximum likelihood bootstrap (ML-BS) and posterior probability (PP) values. The position of the three new species described in this paper are marked in colours, indicated by the herbarium number (UFRN = UFRN-Fungos); the rest of branches indicated with their respective GenBank accession numbers, indicated in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167879#pone.0167879.t001" target="_blank">Table 1</a>.</p

<i>Scleroderma</i> species included in the molecular analyses with their herbarium and/or isolate numbers, country and GenBank accession numbers of internal transcribed spacer (ITS) nuclear ribosomal DNA.

<p>(n.d.: no data). In bold, new species described in this study.</p

<i>Scleroderma duckei</i>.

<p>(A) Fresh basidiomata in the field, bar = 20 mm. (B) Detail of verrucose exoperidium surface, bar = 2 mm. (C) Basidioma cut away side view, bar = 2 mm. (D) Exoperidium hyphae, bar = 20 μm. (E) Basidiospores under LM, bar = 10 μm. (F) Basidiospores under SEM, bar = 2 μm.</p

<i>Scleroderma camassuense</i>.

<p>(A) Fresh basidiomata in the field, bar = 10 mm. (B) Detail of verrucose exoperidium surface, bar = 2 mm. (C) Basidioma cut away side view, bar = 2 mm. (D) Exoperidium hyphae, bar = 20 μm. (E) Basidiospores under LM, bar = 10 μm. (F) Basidiospores under SEM, bar = 2 μm.</p

<i>Scleroderma anomalosporum</i>.

<p>(A) Fresh basidiomata in the field, bar = 30 mm. (B) Detail of reticulation in exoperidium of young basidioma, bar = 2 mm. (C) Basidioma cut away side view, bar = 2 mm. (D) Exoperidium hyphae, bar = 20 μm. (E) Basidiospores under LM, bar = 10 μm. (F) Basidiospores under SEM, bar = 2 μm.</p