Description of a new species of Aegla (Decapoda, Anomura) from the Paran 3 hydrographic basin, Brazil.

Freshwater crustaceans of the genus Aegla are endemic to southern South America, and present greater richness in the river basins of the state of Rio Grande do Sul, Brazil. However, recent studies have shown the enormous potential for discovering new species of Aegla in the state of Paran. In the last six year the number of species recorded has almost doubled, increasing from 9 to 16. In the present work, we expand the current knowledge about the diversity of Aegla in a set of poorly explored drainage basins in the western region of the state and describe a new species, Aegla urussanga n. sp., based on morphological and molecular evidence. A combination of morphological characters supports the new species: orbital spine absent, non-elevated epigastric prominences, robust protogastric lobes with scales, anterior dorsal margin of epimeron 2 armed and with pronounced concavity, sub-rectangular palmar crest of chelipeds, internal margin of the ventral face of the ischium of the cheliped with a proximal stout spine, a distal stout spine, and up to three tubercles with spiniform scales. The molecular data, based on partial COI sequences, also support the distinction of the new species from others that occur in adjacent river basins. The species with the smallest genetic distance from A. urussanga n. sp. is Aegla castro Schmitt, 1942 which occurs in the Iguau River basin. The new species occurs in distinct streams, probably interconnected in the past and currently isolated by the Itaipu reservoir and is the second species of Aegla described from the complex of drainage basins called Paran 3 basin.

Aegla buenoi n. sp. (Decapoda: Anomura): first record of aeglid crab from Cinzas River basin, Brazil.

A new species of freshwater anomuran crab, Aegla buenoi n. sp., is described. The new taxon was collected from two streams within the Cinzas River basin, Paran state, Brazil. We used morphological and molecular data (COI mtDNA) to distinguish the new species from its congeners. Aegla buenoi n. sp. is differentiated by morphological diagnostic features of the cephalothorax, chelipeds, second abdominal epimeron, and uropods. Molecular results confirm the separation of A. buenoi n. sp. from closely related species (A. castro Schmitt, 1942, A. lata Bond-Buckup Buckup, 1994, and A. jacutinga Marl Teixeira, 2020). Hence, our study increases the known diversity of aeglids and reports the first species of Aegla from the Cinzas River basin.

Isolation and characterization of microsatellite markers in two species of the neotropical Epicharis (Hymenoptera, Apidae, Centridini) genus and cross-amplification in related species.

Genetics can provide invaluable tools for management and conservation of bee populations, which are declining worldwide. Among these tools, microsatellite are very useful molecular markers for population analyses. The aim of this study was to isolate and characterize microsatellites for Epicharis (Anepicharis) dejeanii and Epicharis (Epicharis) nigrita, two Neotropical species of solitary bees, both exhibiting the habit of nesting in aggregations. Microsatellite loci were identified from two enriched genomic libraries. The characterization and analysis of loci were carried out using 35 females of E. dejeanii and 34 of E. nigrita. In total, we report the development of 12 microsatellite loci for E. dejeanii and 13 for E. nigrita. For E. dejeanii, all loci were polymorphic, the number of alleles per locus ranged from 2 to 12, averaging 8.7 and, observed and expected heterozygosity were 0.485 (range 0.229-0.857) and 0.633 (range 0.288-0.843), respectively. For E. nigrita, only nine out of 13 loci amplified were polymorphic, the number of alleles per locus ranged from 2 to 12, averaging 5.5. For this species, the observed and expected heterozygosity were 0.440 (range 0.118-0.676) and 0.545 (range 0.167-0.814), respectively. Cross-amplification of primers was successful in other Centridini species. The two sets of loci described for E. dejeanii and E. nigrita species are polymorphic and informative and show promising applicability for both population genetic approaches and relatedness on these and other Centridini species.

Phylogeny of the Neotropical Pacman catfish genus Lophiosilurus (Siluriformes: Pseudopimelodidae)

Lophiosilurus is a monotypic genus represented by L. alexandri, a species endemic to the São Francisco river basin, Brazil. In previous phylogenetic analyses, the genus has been recovered as the sister group of Cephalosilurus. However, few species of Cephalosilurus or few characters were included in those studies. Thus, the current study aims to test the monophyletic hypothesis of the genera Lophiosilurus and Cephalosilurus with a more comprehensive phylogenetic analysis, including all Cephalosilurus species and a representative number of characters. Phylogenetic analyses of 18 terminal taxa (15 ingroups and three outgroups) were conducted based on a combined 75 character matrix, including 70 discrete morphological characters concerning osteology and neuroanatomy, four continuous characters, and the geometric morphometry of the head. The monophyly of the family Pseudopimelodidae was highly supported, and Cephalosilurus is synonymized with Lophiosilurus. The recovered phylogeny of the genus was (L. albomarginatus (L. nigricaudus (L. apurensis (L. fowleri, L. alexandri)))).(AU)

Lophiosilurus é um gênero monotípico representado por L. alexandri, uma espécie endêmica da bacia do rio São Francisco, Brasil. Em análises filogenéticas anteriores, o gênero foi recuperado como grupo irmão de Cephalosilurus. No entanto, poucas espécies de Cephalosilurus ou poucos caracteres foram incluídos nesses estudos. Assim, este estudo tem como objetivo testar a hipótese de monofilia dos gêneros Lophiosilurus e Cephalosilurus, com uma análise filogenética mais abrangente, incluindo todas as espécies de Cephalosilurus e um número representativo de caracteres. As análises filogenéticas de 18 táxons terminais (15 do grupo interno e três grupos externos) foram realizadas com base em uma matriz combinada de 75 caracteres, incluindo 70 caracteres morfológicos discretos de osteologia e neuroanatomia, quatro caracteres contínuos e um de morfometria geométrica da cabeça. A monofilia da família Pseudopimelodidae foi altamente apoiada e Cephalosilurus foi sinonimizado como Lophiosilurus. A filogenia recuperada do gênero foi (L. albomarginatus (L. nigricaudus (L. apurensis (L. fowleri, L. alexandri))).(AU)

Electric eels galore: microsatellite markers for population studies

Fourteen novel microsatellite loci are described and characterized in two species of electric eels, Electrophorus variiand E. voltaifrom floodplains and rivers of the Amazon rainforest. These loci are polymorphic, highly informative, and have the capacity to detect reliable levels of genetic diversity. Likewise, the high combined probability of paternity exclusion value and low combined probability of genetic identity value obtained demonstrate that the new set of loci displays suitability for paternity studies on electric eels. In addition, the cross-amplification of electric eel species implies that it may also be useful in the study of the closely related E. electricus, and to other Neotropical electric fishes (Gymnotiformes) species as tested herein.(AU)

Catorze novos loci microsatélites são descritos e caracterizados em duas espécies de poraquês, Electrophorus varii e E. voltai de planícies alagadas e rios da floresta amazônica. Esses loci são polimórficos, altamente informativos e têm a capacidade de detectar níveis confiáveis de diversidade genética. Da mesma forma, o alto valor de exclusão de paternidade combinado com a baixa probabilidade de identidade genética demonstra que o novo conjunto de loci exibe adequação para estudos de paternidade em poraquês. Além disso, a amplificação cruzada de espécies de peixes elétricos implica que também pode ser útil no estudo da espécie intimamente relacionada E. electricus, e de outras espécies de peixes elétricos neotropicais (Gymnotiformes).(AU)

Reappraisal of the systematics of Microglanis cottoides (Siluriformes, Pseudopimelodidae), a catfish from southern Brazil.

The southern region of Brazil is characterized by high species diversity and endemism of freshwater fishes distributed across geographically isolated river basins. Microglanis cottoides has a widespread range across these river basins and occurs in sympatry with other endemic species of the genus (e.g. M. cibelae, M. eurystoma, and M. malabarbai). Herein we tested the monophyly of M. cottoides and presented for the first time information about the molecular phylogeny of species in the genus. The results suggest that M. cottoides currently forms a non-monophyletic group which includes populations endemic to the Uruguay River basin that are more closely related to M. malabarbai, and excludes M. cibelae, found to be nested within M. cottoides. Based on an integrative approach using morphological and molecular data, we propose M. cibelae as a junior synonym of M. cottoides, and the populations of the Uruguay River basin previously assigned to M. cottoides in fact belong to M. malabarbai. Our molecular phylogeny shows that M. cottoides is sister to M. parahybae, which is also a coastal species, and M. malabarbai is sister of M. garavelloi, both endemic to inland river basins. The time-calibrated phylogeny indicates that the separation between inland and the coastal clades occurred in the Tertiary period, and that the species within the coastal basins diverged in the Pliocene, which overlaps with the diversification times estimated for the two inland species as well. This pattern of diversification corroborates some previous studies with other fishes from the same region.

Genetic Diversity of the Endangered Neotropical Cichlid Fish (Gymnogeophagus setequedas) in Brazil.

Gymnogeophagus setequedas is a rare and rheophilic species of tribe Geophagini, considered endangered in Brazilian red lists. Its previously known geographical distribution range was the Paraná River basin, in Paraguay, and a tributary of the Itaipu Reservoir in Brazil. Since its description no specimens have been collected in the original known distribution area. However, recent records of G. setequedas in the lower Iguaçu River, in a region considered highly endemic for the ichthyofauna, extended the known geographical distribution and may represent one of the last remnants of the species. The aim of this study was to estimate the genetic diversity and population structure of G. setequedas, using microsatellite markers and mitochondrial haplotypes, in order to test the hypothesis of low genetic diversity in this restricted population. Muscular tissue samples of 86 specimens were obtained from nine locations in the Lower Iguaçu River basin, between upstream of the Iguaçu Falls and downstream of the Salto Caxias Reservoir. Seven microsatellites loci were examined and a total of 120 different alleles were obtained. The number of alleles per locus (NA) was 17.429, effective alleles (NE) 6.644, expected heterozygosity (HE) 0.675, observed (HO) heterozygosity 0.592, and inbreeding coefficient (FIS) 0.128. Twelve haplotypes in the D-Loop region were revealed, with values of h (0.7642) and π (0.00729), suggesting a large and stable population with a long evolutionary history. Thus, both molecular markers revealed high levels of genetic diversity and indicated the occurrence of a single G. setequedas population distributed along a stretch of approximately 200 km. The pattern of mismatch distribution was multimodal, which is usually ascribed to populations in demographic equilibrium. Nevertheless, the construction of a new hydroelectric power plant, already underway between the Salto Caxias Reservoir and Iguaçu Falls, could fragment this population, causing loss of genetic diversity and population decline, and for this reason it is necessary to maintain the Iguaçu River tributaries and downstream area from the Lower Iguaçu Reservoir free of additional dams, to guarantee the survival of this species.

A new species of Aegla Leach, 1820 (Crustacea, Anomura) from the Iguaçu River basin, Brazil.

A new species of aeglid crab, Aegla okora n. sp., is described. This species was found in the Iguaçu River basin in Paraná state, southern Brazil. Aegla okora n. sp. was discriminated based on morphological and molecular data (mitochondrial COI). Morphologically, the new species differs from congeners of the same river basin by the presence of a trapezoidal areola and the ventromesial border of the ischium having three tubercles, besides other exclusive additional morphological characteristics. Molecular results demonstrated that there is no overlap between the intraspecific distances of Aegla okora n. sp. and the interspecific distance of other species of Aegla added to the analysis, confirming the separation of species and increasing the known diversity of the Iguaçu River basin.

Development and characterization of microsatellite loci of Microglanis cottoides (siluriformes: pseudopimelodidae) and cross-species amplification

Thirteen microsatellite loci were isolated and characterized in Microglanis cottoides. Of these, two were monomorphic and 11 were polymorphic. These polymorphic loci tested on 24 individuals from a wild population produced a total of 108 different alleles, with levels of variability high, ranging from 2 to 20, with an average of 8.3 alleles per locus. The observed and expected heterozygosity ranged from 0.125 to 0.958 and from 0.119 to 0.931, respectively. A high combined probability of paternity exclusion value and a low probability combined genetic identity value obtained show that the set of loci described herein displays good suitability for paternity studies and differentiation of M. cottoides. Additionally, all thirteen microsatellite primers developed for M. cottoides were tested in four other Pseudopimelodidae species and successful cross-species amplification was achieved for the majority of loci.

Treze loci microssatélites foram isolados e caracterizados em Microglanis cottoides. Destes, dois foram monomórficos e 11 foram polimórficos. Estes loci polimórficos foram testados em 24 indivíduos de uma população selvagem e produziram um total de 108 alelos diferentes, com níveis de variabilidade alta, variando de 2 a 20, com uma média de 8,3 alelos por locus. A heterozigosidade observada e esperada variou de 0,125 a 0,958 e 0,119 a 0,931, respectivamente. Um elevado valor de exclusão de paternidade e um baixo valor de identidade genética foram obtidos, demostrando que o conjunto de loci descritos no presente trabalho exibe boa aplicabilidade no estudo de parentesco e diferenciação populacional em M. cottoides. Adicionalmente, os treze primers de microssatélites desenvolvidos para M. cottoides foram testados em outras quatro espécies de Pseudopimelodidae e a transferabilidade foi obtida para a maioria dos loci.

Cryptic species of the genus Pimelodella (Siluriformes: Heptapteridae) from the Miranda River, Paraguay River basin, Pantanal of Mato Grosso do Sul, Central Brazil

Specimens of Pimelodella captured in the Miranda River, Pantanal of Mato Grosso do Sul State, present morphological features that could indicate at least four species. Therefore, karyotype analysis and molecular biology provided evidence that they were only two species, one showing 2n = 46, and the other, 2n = 52 chromosomes, with only 18% genetic similarity. The morphological analysis evidenced that the dorsal filament is a male characteristic and that the upper lobe of the caudal fin was variable and might or might not be elongated in both species. With respect to morphometric characters, the formation of two groups was evident, but with a small overlap of specimens between them. Among the species with filaments on the dorsal fin observed in the Pantanal, the one with the lesser length of adipose fin base is P. griffini, which corresponds to that with 2n = 46 chromosomes, whereas the species P. taenioptera has 2n = 52 chromosomes. Thus, the accurate detection of these cryptic taxonomic units was only possible with the use of various analysis techniques. Furthermore, it is worth noting that the identification of cryptic species is important for obtaining correct estimates of fish diversity in the Pantanal.

Exemplares de Pimelodella capturados no rio Miranda, Pantanal do Mato Grosso do Sul, apresentavam características morfológicas que poderiam indicar, pelo menos, quatro espécies. Entretanto, com a análise cariotípica e da biologia molecular ficou evidente que se tratava de apenas duas espécies, uma apresentando 2n = 46 e a outra, 2n = 52 cromossomos, e com apenas 18% de similaridade genética. Pela análise morfológica foi observado que o filamento dorsal é uma característica de machos, e o lobo superior da nadadeira caudal se mostrou variável, podendo, ou não, ser alongado em ambas espécies. Com relação aos caracteres morfométricos, também houve a formação de dois grupos, mas com uma pequena sobreposição de exemplares entre eles. Das espécies com filamento na nadadeira dorsal apontadas para o Pantanal, a que possui menor comprimento da base da nadadeira adiposa é P. griffini, o que corresponde àquela com 2n = 46 cromossomos e, ao contrário, a espécie com 2n = 52 cromossomos, é P. taenioptera. Assim, apenas com o emprego de diversas técnicas de análise foi possível o reconhecimento seguro dessas unidades taxonômicas que se mostravam crípticas. Ressalta-se, ainda, que a identificação de espécies crípticas é importante para que estimativas da diversidade de peixes do Pantanal sejam feitas corretamente.