Museu Paraense Emílio Goeldi

Habitat complexity influences the diversity and structure of biological communities by determining the availability and heterogeneity of environmental resources. Spiders, widely recognized as effective environmental bioindicators, are particularly sensitive to changes in habitat structure. This study evaluated how habitat complexity, measured through multiple environmental variables, affects the ground-dwelling spider community in gallery forests, and identified threshold points in species frequency and abundance in relation to these variables. Spiders were sampled using pitfall traps, and environmental variables including canopy cover, understory complexity, grass cover, soil pH and moisture, and litter cover, depth, weight, and composition were measured. A total of 36 samples were collected, yielding 1474 specimens distributed among 112 species/morphospecies and 31 families. The results showed significant interaction effects between canopy cover, litter depth, and litter composition on spider abundance. Furthermore, critical changes in variables such as canopy cover, grass cover, and litter cover, depth, and composition indicate that habitat structure plays a relevant role in the frequency and abundance of individual species. Leprolochus mucuge , Nosferattus sp.1, and Camillina sp.1 were identified as potential indicator species for monitoring environmental degradation in forested areas, while Epicratinus pikachu may serve as an indicator of forest conservation. These findings emphasize the importance of habitat structural for shaping species-specific responses and support the use of ground-dwelling spiders as bioindicators. The identification of indicator species provides valuable information for monitoring programs, management actions, and conservation planning in the Cerrado domain. • Habitat complexity shapes diversity in ground-dwelling spider communities. • Litter and canopy cover significantly affect spider abundance. • Thresholds identified for species response to habitat structure changes. • Key spider species indicate forest degradation or conservation status.

Assessing how the disturbances affect the physical structure and biodiversity of freshwater ecosystems has become a critical research priority. Bauxite mining is economically important in the Amazon, but associated infrastructure may influence freshwater biodiversity. We evaluated the effects of a bauxite ore pipeline on the community structure of semiaquatic bugs (Heteroptera: Gerromorpha) in 40 streams of the eastern Amazon, including 20 sites crossed by the pipeline and 20 control sites. We tested whether (i) species abundance and richness upstream and downstream of control sites would be higher than in pipeline sites, (ii) upstream sites would show greater abundance and richness due to species sensitivity and habitat alteration in sites crossed by the pipeline, (iii) community composition would differ between pipeline and control sites, with characteristic species for each treatment, and (iv) the pipeline would indirectly influence communities through changes in habitat quality, riparian cover, and abiotic variables. Multivariate analyses indicated clear differences in community composition, with indicator species characterizing each condition, including the species Rhagovelia jubata in pipeline streams and Stridulivelia alia and Stridulivelia strigosa in control streams. Abundance showed a tendency to be higher in control streams, whereas richness was associated with abundance but not with habitat integrity. These findings indicate that, although diversity metrics remained similar, pipeline installation is linked to changes in species composition, reflecting shifts in local environmental conditions.

The genus Siparuna Aubl. (Siparunaceae) comprises aromatic species widely distributed in the Neotropics and traditionally used in folk medicine to treat fever, inflammation, malaria, gastrointestinal and respiratory disorders, and as natural repellents. These plants are rich in essential oils (EOs), mainly composed of monoterpenes and sesquiterpenes, which exhibit a broad spectrum of biological properties. The present study analyzes the variability in the chemical composition and biological activities of EOS from species of the genus Siparuna . A review of the current literature revealed that the chemical composition of Siparuna essential oils (EOs) is characterized by a predominance of compounds, including bicyclogermacrene, germacrene D, β-myrcene, α-pinene, spathulenol, and curzerenone. It is evident that there is notable chemical variability among species and geographical locations. In contrast, despite the presence of chemical variability, antioxidant activity remained consistently low or absent. Significant antimicrobial, antifungal, insecticidal, antiparasitic, and anti-inflammatory activities were documented. Siparuna guianensis demonstrated notable synergistic antimicrobial properties in combination with antibiotics, a pronounced larvicidal effect against Aedes aegypti when nanoencapsulated, and acaricidal activity against Rhipicephalus microplus . Additionally, it exhibited ethnopharmacological relevance as an antimalarial agent. Other species, including Siparuna brasiliensis , Siparuna muricata, and Siparuna thecaphora , also demonstrated promising biological activities. The employment of technological strategies, including nanoemulsions and encapsulation, has been demonstrated to enhance the stability and efficacy of EOs, thereby reinforcing their potential as bioinsecticides and phytotherapeutics. However, significant knowledge gaps persist, particularly concerning standardization of extraction methods, toxicological safety, mechanisms of action, and conservation strategies for sustainable use. The evidence presented in this study underscores the significance of Siparuna as a promising reservoir of bioactive metabolites, offering substantial pharmaceutical, agricultural, and industrial applications. This analysis emphasizes the necessity for integrative approaches that integrate ethnobotanical knowledge with contemporary biotechnological tools to facilitate the exploration of this genus potential.

<title>Abstract</title> Molecular phylogenetic evidence demonstrate the monophyly of five genera ( <italic>Bowdichia, Diplotropis, Guianodendr on, Leptolobium</italic> and <italic>Staminodianthus</italic> ) into a recircumscribed Leptolobieae. Even though recognition of the tribe is highly supported by molecular data, morphological characterization of its taxa is still challenging. In this context, our study aimed to study the seedling morphology of eleven species from all genera of Leptolobieae. The seedling morphology of <italic>Staminodianthus racemosus</italic> is here described for the first time. The observed characters were scored into a morphological matrix and mapped onto a phylogeny in order to detect potential synapomorphies for major clades. Three morphological types of seedlings were observed and described: phanero-epigeo-foliaceous seedlings (PEF) in <italic>Bowdichia virgilioides</italic> and <italic>Leptolobium</italic> spp., crypto-hipogeo-reserve seedlings (CHR) in <italic>Guianodendron praeclarum</italic> and <italic>Diplotropis martiusii, and</italic> phanero-hipogeo-reserve seedlings (PHR) in <italic>S. racemosu</italic> s. PEF morphotype was reconstructed as the mostly likely state in the most recent common ancestor (MRCA) of Leptolobieae, with subsequent transitions to the CHR morphotype in <italic>Diplotropus</italic> and <italic>Guianodendron</italic> , and to the PHR morphotype in <italic>S. racemosus</italic> . Another five seedling characters were reconstructed as potential synapomorphies for clades in Leptolobieae: hypocotyl shape and length, epicotyl length, presence of glands at the eophyl axyl and the number of leaflets at the seedling first node. For <italic>Leptolobium</italic> , the phyllotaxy, number of eophylls from first to third node, leaflet shape, apex and base form, and the presence of stipels are diagnostic characters within species and could be used for taxonomic purposes.

ABSTRACT Semiaquatic bugs (Hemiptera, Heteroptera, Gerromorpha) are predatory insects currently represented in Brazil by five families, 38 genera, and 250 species. Studies in the northern portion of the country are concentrated between the two largest cities in the region, Manaus and Belém, resulting in knowledge gaps. Based on material recently collected in the states of Acre and Amazonas, we present here the description of five new species: Rheumatobates acreanus Rodrigues and Moreira, sp. nov., R. apurina Rodrigues and Moreira, sp. nov., R. bicolor Rodrigues and Moreira, sp. nov., R. chicomendesi Rodrigues and Moreira, sp. nov., and Tachygerris septentrionalis Rodrigues and Moreira, sp. nov., Additionally, we detected synonymy between Euvelia discala Polhemus and Polhemus, 1984 (senior) and E. meta Molano, Moreira and Morales, 2016 (junior), and between R. bonariensis (Berg, 1898) (senior) and R. minimus Drake, 1958 (junior). Furthermore, we provide figures of the type specimens of R. bonariensis, R. klagei Schroeder, 1931, R. minimus, and R. wrighti Drake and Harris, 1937. Finally, new records from northern Brazil are provided for 29 species of semiaquatic bugs, of which four are first recorded from Brazil (Metrobates fugientis Drake and Harris, 1945, Telmatometra indentata Kenaga, 1941, Trepobatoides boliviensis Hungerford and Matsuda, 1958 and Hydrometra williamsi Hungerford and Evans, 1934), 26 from Acre, and three from Amazonas. Our study increases to 258 the number of gerromorphan species recorded from Brazil, to 29 those known from Acre, and to 92 those from Amazonas. https://zoobank.org/urn:lsid:zoobank.org:pub:FB2B6A2E-C36E-46B0-B94C-C486ED3D0A7B

Twelve new species of the genus Stethorrhagus Simon, 1896 are described: S. bradypus sp. nov. (♂♀), S. callithrix sp. nov. (♂♀), S. loxodonta sp. nov. (♂♀), S. naja sp. nov. (♂♀), S. papilio sp. nov. (♀) and S. sylvilagus sp. nov. (♂♀) from Colombia; S. canis sp. nov. (♀), S. felis sp. nov. (♂♀), S. mandrillus sp. nov. (♂♀), S. ovis sp. nov. (♂♀), S. sciurus sp. nov. (♀) and S. tremarctos sp. nov. (♂♀) from Ecuador, increasing the number of known species in the genus from 15 to 27. Detailed morphological descriptions, photos of the body and copulatory organs, illustrations of copulatory organs, and comparisons with closely related species are given for all new species, along with emended diagnoses, distribution maps and an updated key to all currently accepted species in the genus. The geographical distribution of S. lupulus and S. oxossi are updated with new records from Brazil and Peru, and Brazil, respectively. Additionally, photographs of the type material of S. limbatus Simon, 1896, S. nigrinus (Berland, 1913), S. maculatus (L. Koch, 1866), S. hyula Bonaldo &amp;#38; Brescovit, 1994, S. planada Bonaldo &amp;#38; Brescovit, 1994, S. duidae Gertsch, 1942, S. roraimae Gertsch, 1942, S. peckorum Bonaldo &amp;#38; Brescovit, 1994, and S. archangelus Bonaldo &amp;#38; Brescovit, 1994 are supplied.

Abstract Species descriptions in taxonomy have become increasingly comprehensive, yet disparities persist across taxa and regions. We assess temporal trends in mammal species descriptions (1990–2022) using four proxies of comprehensiveness—counts of examined specimens and compared taxa, number of pages (only from the Methods/Results sections), and number of evidence lines (i.e., analytical tools and techniques). Using generalised linear models, we assessed how these proxies are explained by factors associated with species’ biology, geography, and taxonomic practice. Most new species derive from tropical regions, particularly rodents and bats, reflecting global discovery hotspots. Descriptions have grown more rigorous over time, with expanded specimen sampling, broader taxonomic comparisons, and integrative methods. However, disparities emerge along geographic and biological axes: temperate-region descriptions incorporate more evidence lines, while small-bodied and tropical species (especially bats) remain understudied due to sampling biases and resource limitations. Body size inversely correlates with description length, as smaller species often require advanced diagnostics. Species-rich genera show greater comprehensiveness, likely due to heightened diagnostic scrutiny, though bats exhibit the opposite trend, possibly due to taxon-specific sampling challenges. Our findings highlight progress in taxonomic rigor but underscore persistent gaps tied to geography, body size, and accessibility of analytical tools. Addressing these disparities requires targeted investments in local capacity, equitable collaboration, and accessible methodologies to strengthen global taxonomic infrastructure and support conservation priorities.

The uncertain identities of Hyla geographica Spix, 1824 (= Boana geographica) and Hyla geographica var. sive semilineata Spix, 1824 (= Boana semilineata) are long-standing problems in the taxonomy of the Boana semilineata species group. Several factors have contributed to this issue, such as the loss of specimens upon which both original descriptions were based, unclear identities of various synonyms, the morphological characters that vary widely and are used for diagnosis, and the scarcity of topotypical samples. Herein, we reanalyze the phylogenetic relationships among species within the B. semilineata group based on genetic data from the mitochondrial genes 16S and COI. We also report on additional topotypical material, including topotypes of most taxa under the synonymy of both B. geographica and B. semilineata. To alleviate some of the taxonomy confusion in the group, we designate neotypes for B. geographica and B. semilineata and review the taxonomy of the group.

ABSTRACTMangrove forests are a relevant coastal ecosystem, and Brazil holds the second‐largest mangrove area worldwide, with over two‐thirds of it located in the Amazon region. However, despite their singular environmental characteristics and ecological importance, macroalgal communities in Amazonian mangroves remain poorly understood. Therefore, this study investigates the composition and biomass of macroalgae from two mangrove forests on the Brazilian Amazon coast and their temporal variation. Overall, higher precipitation was observed in May and lower in September, while air temperatures were higher in November and lower in January. Estiva tidal creek exhibited higher salinity and conductivity, while Taici had higher turbidity, NO2−, and PO4−3 levels. Seven Rhodophyta species were identified, with Bostrychia calliptera, B. moritziana, and Catenella caespitosa being the most frequent and dominant in terms of biomass across all months and substrates at both sites. Richness and biomass varied significantly across months, with the highest values observed in the dry season (September) and at the innermost site (Taici). Among the substrates, rhizophores had significantly higher biomass in Taici, whereas pneumatophores showed similar biomass across both sites. DistLM analysis indicated that salinity, precipitation, NO2− concentrations, and substrate type were the main drivers of macroalgal biomass. These findings highlight the significant spatial and temporal variations in environmental conditions and macroalgal biomass in mangrove ecosystems, emphasizing the need for site‐specific management and conservation strategies.