Interspecific cytogenetic relationships in three Acestrohynchus species (Acestrohynchinae, Characiformes) reveal the existence of possible cryptic species

The karyotypes and chromosomal characteristics of three Acestrorhynchus Eigenmann et Kennedy, 1903 species were examined using conventional and molecular protocols. These species had invariably a diploid chromosome number 2n = 50. Acestrorhynchus falcatus (Block, 1794) and Acestrorhynchus falcirostris (Cuvier, 1819) had the karyotype composed of 16 metacentric (m) + 28 submetacentric (sm) + 6 subtelocentric (st) chromosomes while Acestrorhynchus microlepis (Schomburgk, 1841) had the karyotype composed of 14m+30sm+6st elements. In this species, differences of the conventional and molecular markers between the populations of Catalao Lake (AM) and of Apeu Stream (PA) were found. Thus the individuals of Para (Apeu) were named Acestrorhynchus prope microlepis. The distribution of the constitutive heterochromatin blocks was species-specific, with C-positive bands in the centromeric and telomeric regions of a number of different chromosomes, as well as in interstitial sites and completely heterochromatic arms. The phenotypes of nucleolus organizer region (NOR) were simple, i. e. in a terminal position on the p arm of pair No. 23 except in A. microlepis, in which it was located on the q arm. Fluorescence in situ hybridization (FISH) revealed 18S rDNA sites on one chromosome pair in karyotype of A. falcirostris and A. prope microlepis (pair No. 23) and three pairs (Nos. 12, 23, 24) in A. falcatus and (Nos. 8, 23, 24) in A. microlepis; 5S rDNA sites were detected in one chromosome pair in all three species. The mapping of the telomeric sequences revealed terminal sequences in all the chromosomes, as well as the presence of interstitial telomeric sequences (ITSs) in a number of chromosome pairs. The cytogenetic data recorded in the present study indicate that A. prope microlepis may be an unnamed species. © 2020, Alber Sousa Campos et al

Two novel species of Lactifluus subg. Pseudogymnocarpi (Russulaceae) from Brazil

Two new species in Lactifluus subg. Pseudogymnocarpi, Lf. umbilicatus and Lf. venosellus were collected from Amazonian and Atlantic forests of Brazil, respectively. Detailed macro- and micromorphological descriptions, including scanning electron microscopy images of the basidiospores, are provided. The putative phylogenetic placement of these taxa was investigated based on ITS sequence analyses. Comparisons with related taxa are discussed. Copyright © 2020 Magnolia Press

Honey botanical origin of stingless bees (Apidae Meliponini) in the Nova América community of the Sateré Mawé indigenous tribe, Amazon, Brazil

This study analysed the pollen present in honey samples collected from colonies of stingless bees (Meliponini) from the meliponary of the Nova América community of the Sateré Mawé tribe, located on the Maruá River, Maués municipality, Amazonas state, Brazil (03° 39ʹ 45.00″ S, 57° 20ʹ 17.99″ W). Collections were made directly from honey storage pots. A total of 47 pollen types were identified, belonging to 22 plant families. Bees with the largest number of pollen types were Melipona seminigra (31 collected pollen types), followed by Melipona sp. (27 pollen types), Scaptotrigona sp. (25 pollen types), and Melipona dubia (19 pollen types). Plant families most commonly collected were: Anacardiaceae, Arecaceae, Burseraceae, Chrysobalanaceae, Dichapetalaceae, Dilleniaceae, Euphorbiaceae, Fabaceae, Lecythidaceae, Melastomataceae, Myrtaceae, Rhamnaceae and Salicaceae. Scaptotrigona sp. had the highest pollen types diversity (H′ = 2.32) and, consequently, greatest between-collection uniformity. Trophic niche overlap was significant between the following pairs of bees: M. seminigra and M. dubia (Oi = 0.93); M. seminigra and Scaptotrigona sp. (Oi = 0.79) and M. dubia and Scaptotrigona sp. (Oi = 0.69). These data demonstrate the importance of these shared groups of plants for the maintenance of these bees and, consequently, for the development of meliponiculture in Brazilian Amazonia. © 2020, © 2020 Collegium Palynologicum Scandinavicum

Unveiling geographical gradients of species richness from scant occurrence data

Aim: Despite longstanding investigation, the gradients of species richness remain unknown for most taxa because of shortfalls in knowledge regarding the quantity and distribution of species. Here, we explore the ability of a geostatistical interpolation model, regression-kriging, to recover geographical gradients of species richness. We examined the technique with an in silico gradient of species richness and evaluated the effect of different configurations of knowledge shortfalls. We also took the same approach for empirical data with large knowledge gaps, the infraorder Furnariides of suboscine birds. Innovation: Regression-kriging builds upon two cornerstones of geographical gradients of biodiversity, the spatial autocorrelation of species richness and the conspicuous association of species with environmental factors. With this technique, we recovered a simulated gradient of richness using < 0.01% of sampling sites across the region. The accuracy of the regression-kriging is higher when input samples are more evenly distributed throughout the geographical space rather than the environmental space of the target region. Moreover, the accuracy of this method is more sensitive to the sufficiency of sampling effort within cells than to the quantity of sampled localities. For Furnariides birds, regression-kriging provided a geographical gradient of species richness that resembles purported patterns of other groups and illustrated ubiquitous shortfalls of knowledge about bird diversity. Main conclusions: Geostatistical interpolation, such as regression-kriging, might be a useful tool to overcome shortfalls in knowledge that plague our understanding of geographical gradients of biodiversity, with many applications in ecology, palaeoecology and conservation. © 2020 John Wiley & Sons Lt

Feeding of Arapaima sp.: integrating stomach contents and local ecological knowledge

The giant arapaima (Arapaima sp.) has been described as a fish of change in Amazonia because of its important role in the conservation of floodplains, food security and income generation for rural communities. Nonetheless, despite the cultural, ecological and economic importance of arapaima, data on diet are scarce. Aiming to expand knowledge about arapaima diet in western Amazonia, scientific knowledge was integrated with the knowledge of local dwellers. During the low-water period (September 2018) and the falling-water period (June 2019), arapaima stomachs were collected from 11 floodplain lakes in the middle Juruá River. All fishes were measured [TL (total length)] and sexed. Food items from each stomach were categorized as fishes, invertebrates, plants and bone remains and weighed. Also, in the latter period, experienced local fishers were interviewed about arapaima feeding. This integrated approach revealed that young arapaima eat fish and invertebrates but adult arapaima eat fish of a wide range of species, which were mainly of low and intermediate trophic positions. This study reports the first case of cannibalism for arapaima and also shows that during the low-water period, many individuals had empty stomachs or only some small fish-bone remains and/or plant material. Arapaima sex and TL had no influence on the absence of prey in stomach contents. Overall, it can be concluded that local people had consistent ethnobiological knowledge of arapaima feeding ecology that could be useful within management projects in the region. © 2020 The Fisheries Society of the British Isle

Neuromast distribution and its relevance to feeding in Neotropical freshwater stingrays (Elasmobranchii: Potamotrygonidae)

The mechanosensory system in batoids has a unique sensory canal distribution located on both dorsal and ventral surfaces of the body. Due to the opposite position of eyes and mouth, ventral lateral-line canals are essential to detect and capture prey buried in the substrate. The present study analyzes the density of neuromasts in ventral lateral-line canals as well as their specific distribution patterns to help to understand the mechanisms involved in the foraging activities in potamotrygonid stingrays. The organization of the lateral-line canals was described in Potamotrygon albimaculata, P. jabuti and P. schroederi. Neuromasts were quantified in each canal of the ventral surface and endemic their densities were compared among P. albimaculata, P. jabuti, P. schroederi, P. wallacei, and Paratrygon aiereba. The orbito-nasal component of the infraorbital canal was examined for all genera of Potamotrygoninae to understand its origin and connection patterns. Despite similarities in the morphology of the lateral line in the examined potamotrygonid species, differences of the densities of neuromasts were observed. The distinct web-like infraorbital canal in Paratrygon aiereba held a significantly higher number of neuromasts, which apparently compensates the lower density of neuromasts along its ventral surface. The orbito-nasal component of the infraorbital canal presents connections between infraorbital and nasal canals, except for P. aiereba, which has a supra-infraorbital canals’ connection. The complex distribution of lateral line canals and their neuromasts indicate distinct sensory abilities that probably provide a high capability to detect a variety of prey in different types of substrate. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature

Terpenos de culturas in vitro de Duroia saccifera (Rubiaceae) e avaliação das atividades antibacteriana, antiangiogênica e antioxidante dos extratos

Duroia saccifera (Mart. Ex Roem. & Schult.) K. Schum. (Rubiaceae) occurs in the Amazon rainforest. In natura plant extracts of the species have shown antioxidant, antimicrobial even against Mycobacterium tuberculosis activity, showing their medicinal potential. Based on this, the objective of this work was to study phytochemically and some biological activities of extracts of in vitro D. saccifera cultures, as well as to describe differences involved in in vitro propagation methods and calogenesis induction time, based on the chemical profile of the extracts hexanes, ethyl acetate (EtOAc) and methanolic (MeOH) from seedlings, calli, and cell suspensions. Seedlings of D. saccifera were used to prepare seedling extracts and as a source of explants to initiate the establishment of callus and cell suspension cultures. The plant material was extracted with the organic solvents hexane, EtOAc and MeOH. Callus EtOAc and seedling MeOH extracts were fractionated in open column. All extracts and fractions were analyzed by Comparative Thin Layer Chromatography (TLC). Callus extracts and suspensions were tested in antimicrobial and antioxidant assays; cell suspension extracts were tested for angiogenic activity. Callus extracts and cell suspensions had a similar chemical profile, and the seedling extracts were remarkably different, however, all extracts were rich in terpenoids. The comparison of the chemical profile of the extracts of the cultures and explants with different degrees of differentiation made it possible to verify the presence of iridoids only in cultures with differentiated cells. A mixture of β-sitosterol, stigmasterol and oleanolic and ursolic acid were obtained from the EtOAc extract. Seedling fractionation resulted in the isolation of the iridoid monotropein methyl ester, obtained for the first time in the species. Of the extracts tested, the EtOAc extracts of callus and suspensions and hexanic callus extract showed bacteriostatic activity. EtOAc extract from cell suspensions showed significant antiagiogenic activity. The results found in this work demonstrate the great potential of D. saccifera in vitro cultures for the supply of mainly terpenoid active secondary metabolites and stimulate the continued fractionation of callus EtOAc extract and seedling MeOH to isolate, identify and analyze other possible active substances that may lead to the discovery of new drugs for the treatment of tuberculosis.Duroia saccifera (Mart. Ex Roem. & Schult.) K. Schum. (Rubiaceae) ocorre na floresta Amazônica. Extratos de plantas in natura da espécie têm apresentado atividade antioxidante, antimicrobiana inclusive frente a Mycobacterium tuberculosis mostrando seu potencial medicinal. Com base nisso, esse trabalho teve como objetivo estudar fitoquímica e algumas atividades biológicas de extratos de culturas in vitro de D. saccifera, além de descrever diferenças envolvidas nos métodos de propagação in vitro e no tempo da indução da calogênese, baseando-se no perfil químico dos extratos hexânicos, acetato de etila (AcOEt) e metanólicos (MeOH) de plântulas, calos, e suspensões celulares. Mudas de plântulas de D. saccifera foram utilizadas para a preparação dos extratos de plântulas e como fonte de explantes para iniciar o estabelecimento dos cultivos de calos e suspensões celulares. O material vegetal foi extraído com os solventes orgânicos hexano, AcOEt e MeOH, os extratos AcOEt dos calos e MeOH das plântulas foram fracionados em coluna aberta. Todos os extratos e frações foram analisados por Cromatografia em Camada Delgada Comparativa (CCDC). Os extratos dos calos e as suspensões foram testados em ensaios antimicrobiano e antioxidante, os extratos das suspensões celulares foram testados frente a sua atividade angiogênica. Os extratos de calos e suspensões celulares apresentaram um perfil químico semelhante, sendo os extratos das plântulas notavelmente diferentes, porém, todos os extratos se mostraram ricos em terpenoides com os reveladores testados. A comparação do perfil químico dos extratos das culturas e de explantes com diferentes graus de diferenciação, possibilitou verificar a presença de iridoides somente nas culturas com células diferenciadas. Do extrato AcOEt obteve-se uma mixtura de β-sitosterol e estigmasterol e outra de ácido oleanólico e ursólico, obtidas pela primeira vez em culturas in vitro desta espécie. O fracionamento do extrato MeOH de plântulas resultou no isolamento do iridoide éster metílico de monotropeína, obtido pela primeira vez na espécie. Os extratos AcOEt dos calos e suspensões, e o extrato hexânico dos calos apresentaram atividade bacteriostática. O extrato AcOEt das suspensões celulares apresentou atividade antiangiogênica significativa. Os resultados encontrados neste trabalho demonstram o grande potencial das culturas in vitro de D. saccifera para o suprimento de metabólitos secundários ativos, principalmente terpenoides, e estimulam a continuação do fracionamento do extrato de AcOEt dos calos e MeOH das plântulas, para isolar, identificar e analisar outras possíveis substâncias ativas que podem levar à descoberta de novos medicamentos para o tratamento da tuberculose

Pre-Columbian soil fertilization and current management maintain food resource availability in old-growth Amazonian forests

Aims: The extent and persistence of pre-Columbian human legacies in old-growth Amazonian forests are still controversial, partly because modern societies re-occupied old settlements, challenging the distinction between pre- and post-Columbian legacies. Here, we compared the effects of pre-Columbian vs. recent landscape domestication processes on soils and vegetation in two Amazonian regions. Methods: We studied forest landscapes at varying distances from pre-Columbian and current settlements inside protected areas occupied by traditional and indigenous peoples in the lower Tapajós and the upper-middle Madeira river basins. By conducting 69 free-listing interviews, participatory mappings, guided-tours, 27 forest inventories, and soil analysis, we assessed the influences of pre-Columbian and current activities in soils and plant resources surrounding the settlements. Results: In both regions, we found that pre-Columbian villages were more densely distributed across the landscape than current villages. Soil nutrients (mainly Ca and P) were higher closer to pre-Columbian villages but were generally not related to current villages, suggesting past soil fertilization. Soil charcoal was frequent in all forests, suggesting frequent fire events. The density of domesticated plants used for food increased in phosphorus enriched soils. In contrast, the density of plants used for construction decreased near current villages. Conclusions: We detected a significant effect of past soil fertilization on food resources over extensive areas, supporting the hypothesis that pre-Columbian landscape domestication left persistent marks on Amazonian landscapes. Our results suggest that a combination of pre-Columbian phosphorus fertilization with past and current management drives plant resource availability in old-growth forests. © 2020, The Author(s)

Review of the new world genus acrotaphus townes, 1960 (Hymenoptera: Ichneumonidae: Pimplinae), with descriptions of fifteen new species

Acrotaphus Townes, 1960 is a moderately large New world genus of spider attacking parasitoid wasps. Previously, it comprised 11 species. The present study aims to review the genus, and includes descriptions of 15 new species: A. amajari sp. n., A. amazonicus sp. n., A. bodoquenaensis sp. n., A. cuzconus sp. n., A. dolichopus sp. n., A. homeofranklini sp. n., A. jackiechani sp. n., A. kourou sp. n., A. micrus sp. n., A. monotaenius sp. n., A. nambilloensis sp. n., A. pseudoamazonicus sp. n., A. pseudomexicanus sp. n., A. venezuelanus sp. n. and A. zampieronae sp. n.. In addition, we present new characters for the study of the genus and describe the male genitalia for the first time. An illustrated key and maps to the species of the genus are provided. Acrotaphus franklini Gauld, 1991 and A. pseudoamazonicus sp. n. were recorded from the nests of Trypoxylon (Trypargilum) lactitarse Saussure, 1867 (Hymenoptera: Crabronidae). © 2020 Magnolia Pres