First-order Streams Research Articles

A typical coastal plain taxon in central Brazil: Relationships and description of a new species of non-annual killifish (Cyprinodontiformes; Rivulidae) from the Paraná River basin

We describe a new species of the genus Atlantirivulus from a small first-order stream on the right margin of the Paraná River basin in the Mato Grosso do Sul, Brazil. The region of occurrence of the new species is known to be a hotspot for Melanorivulus species. This area, however, is approximately 700 km away from the record of occurrence of its closest congeners, which are distributed along the Brazilian coast in different hydrographic basins. Atlantirivulus enigmaticus, new species, is distinguished from all congeners by it s unique coloration, which consists of the flank being purplish grey with light green iridescence with brownish red dots scattered along of the body, by the neuromasts of the infraorbital series being aligned around eye, and by the presence of the short ventral process of the posttemporal. The phylogenetic position of the new species within the Atlantirivulus genus was based on molecular phylogenetic analysis using sequences of the mitochondrial gene cytochrome oxidase subunit 1. The results show that the new species is closely related to Atlantirivulus luelingi from the coastal drainages of the Brazilian state Santa Catarina. The phylogenetic position of the new species among congeners endemic to coastal river basins may be related to ancestral connections between coastal drainages and the Paraná River basin. The new species constitutes the westernmost record for the genus, and the first record of Atlantirivulus in the Paraná River basin. Insufficient collection efforts in areas of potential occurrence for the group and extinction processes in the broad region between the locality of the new species and the distribution areas of the remaining species may be a possible explanation for this disjunct distribution.

Field and laboratory life cycle studies of Malenka depressa (Banks, 1898) (Plecoptera: Nemouridae)

During 1982–1985, laboratory and field studies of 125 eggs, 8055 nymphs and 1426 adults indicated a univoltine slow life cycle for Malenka depressa (Banks, 1898) in a first-order perennial stream in the Mediterranean climate of the San Francisco Bay area. Nymphal growth and adult emergence were continuous throughout the year, further enhanced by a thick, protective tree canopy shading of the canyon that provided an insulated stabilised thermal tube of cool air, ground and stream water temperatures. Leaf senescence of the overhead California bay trees was a perennial source of allochthonous food for the immature stages. Maximum assimilation efficiency for middle to late-nymphal growth stages fed on bay leaves was 42% at 10 °C.

Lower diversity in benthic macrofaunal assemblages associated with increasing riparian deforestation in first-order lowland tropical streams

ABSTRACT In aquatic ecosystems, benthic macroinvertebrates are strongly influenced by riparian habitat quality. We investigated associations between riparian deforestation, stream habitat variables and benthic macroinvertebrate assemblage structure, particularly sensitive taxa. We sampled macroinvertebrates and physical-chemical variables during both the dry and wet seasons at three sites, each with low, medium, and high levels of riparian deforestation, in each of three first-order streams in the lower zone of the Caeté river in eastern Amazonia, Brazil. The relationships were examined using Generalized Linear Mixed-Models (GLMM) and multivariate analysis. Macroinvertebrate families most associated with deforestation levels were determined by Indicator Species Analysis. We hypothesized that lower riparian deforestation is associated with greater diversity, especially of sensitive taxa, and lower dominance. A total of 3,427 macroinvertebrates distributed in 54 families were found, of which 25 were sensitive taxa. Sites with high deforestation, associated with Glossiphonidae, Tubificidae, and Naididae, differed from those with medium (associated with Limnephilidae) and low (associated with Polycentropodidae and Hydropsychidae) deforestation. Families and abundance of EPTC (Ephemeroptera, Plecoptera, Trichoptera, and Coleoptera) were lower at high deforestation, with significant losses of taxa compared to the whole assemblage. In Caeté headwaters, deforestation is an important factor for structuring benthic macroinvertebrate assemblages.

Influence of a protected riparian corridor on the benthic aquatic macroinvertebrate assemblages of a small northern Michigan (USA) agricultural stream

The biotic integrity of streams is frequently compromised by anthropogenic disturbance; thus, it is important to study the potential mitigating effects of undisturbed riparian zones on streams within disturbed watersheds. In this study, two first-order northern Michigan streams located 1 km apart in adjacent agricultural watersheds, but with differing riparian land use, were compared to observe the effects of intact forest within the immediate 100 m stream corridor. Both streams had high specific conductance values associated with agricultural streams. The stream with a primarily forested riparian corridor, however, had greater canopy cover, faster stream velocity, greater coarse substrate, lower percentage of organic sediment, lower water temperatures, higher dissolved oxygen, higher taxonomic richness, higher relative biomass of shredders, lower relative biomass of gathering collectors, and more pollution intolerant taxa than the stream with a primarily agricultural corridor. Moreover, the benthic macroinvertebrate assemblages were highly distinct from each other, with the riparian forested stream dominated by aquatic insects like mayflies and caddisflies, and the agricultural stream by non-emergent isopods and amphipods. These results demonstrate the effects of a buffer zone on stream substrate composition, water physicochemistry, and benthic assemblages, and indicate the importance of preserving riparian zones within agricultural watersheds.

Ecological Significance of Aquatic Macroinvertebrates in Headwater Streams

Headwater streams are the starting points of river ecosystems, that consist of an array of unique microhabitats. Most of these stream segments are first-order streams and these aquatic ecosystems provide habitats for many macroinvertebrates including arthropods, mollusks, annelids, nematodes, and turbellarians. These species play a significant role in maintaining the ecological integrity of the river ecosystem. Specifically, their feeding habits of scraping, collecting, shuddering, and predating make a significant contribution to maintaining stable food webs within the stream ecosystems. These macroinvertebrates are highly sensitive to environmental changes and consequently, they have been used as indicators of environmental quality. Although the aquatic macroinvertebrates play a crucial role in headwater streams, they face stresses caused either by nature itself or man leading to their extinction on certain occasions. Global warming, acidification, deforestation, forest fires, industrialization, intensive agriculture, and livestock farming practices have been identified as potential stresses behind the extinction and biodiversity losses of macroinvertebrates in headwater streams. Therefore, the abundance and distribution of macroinvertebrates in headwater streams need to be critically considered in developing criteria for development projects, agricultural practices, and other environmental management strategies to protect and conserve these unique environmental creatures.

Ecological importance of low-order streams to macroinvertebrate community composition in Afromontane headwater streams

Low-order streams contribute to the abiotic and biotic character of large rivers and are renowned for harboring unique forms of aquatic flora and fauna. However, most studies on headwater streams mainly focus on the mainstems and overlook the contribution of the tributary systems. Moreover, low-order streams are generally overlooked in legislation and bioassessment programs, and consequently not protected in many countries. To contribute to the recognition of the ecological importance of low-orders streams, this study focused on determining whether river network characteristics and associated physico-chemical parameters can be used to effectively predict the variabilities in macroinvertebrate assemblage characteristics between first-order and second-order streams in the headwaters of the Nzoia River Basin, Kenya. The study quantified the structural and functional community composition, diversity, similarity, and richness of macroinvertebrate communities between the two river systems. Dissolved oxygen, coarse particulate organic matter, conductivity, stream width, depth, discharge and flow velocity were the main predictors of the diversity and distribution of macroinvertebrates in the first order and second-order streams. The first order streams recorded higher abundance of macroinvertebrates than the second-order streams. Taxa from families Ephydridae, Elmidae, Gomphidae, and genera Euthraulus, Neoperla, Orthothrichia and Prosopistoma were limited to the second-order stream sites while families Ceratopogonidae, Pisuliidae, Dytiscidae and genus Trichosetodes occurred exclusively in the first-order stream sites. Collector-filterers and collector-gatherers were the most abundant functional feeding groups (FFGs) in the two river systems. Scrapers were abundant in the second-order stream while shredders were abundant in the first order streams. The distinctness in the structural and functional composition of macroinvertebrates between the two river systems suggests that linkages among streams in a network as exemplified in the Nzoia River Basin, support and foster biodiversity.

Quantitative morphometric analysis of streams in extreme humid areas a case study of the Um-Mawiong river basin, Mawsynram, Meghalaya

Quantitative morphometric analysis of the drainage system is essential to characterising a watershed, as all the hydrologic and geomorphic processes occur within the watershed. Consequently, this plays a crucial role in understanding the geo-hydrological attributes of a drainage basin to the terrain feature and its flow patterns, thus enabling the estimate of the incidence of infiltration and runoff and other related hydrological characteristics of a watershed, which strongly impacts natural resource conservation. The study area selected is the Um-Mawiong River basin in Mawsynram, Meghalaya. The basin shows a dendritic pattern that highlights the homogeneity in the texture of the basin. Results suggest that the stream frequency of the basin is 19.10 km², suggesting a faster surface runoff and less infiltration. In addition, it has an Elongation ratio of 0.75 indicating an elongated basin shape. The current study demonstrates that the implementations of GIS techniques are trustworthy, efficient, and capable of managing extensive databases for managing river basins. The present study tries to analyse the linear, areal and relief aspects of the basin using a GIS environment and manipulated for different calculations. The analysis reveals that the total number of stream segments and length are maximum in first-order streams and decrease as stream order increases. The drainage density exhibits a high degree of positive correlation, i.e., 0.87, with its frequency suggesting an increase in stream population concerning increasing drainage density and vice versa.

Mapping Prospects for Artificial Groundwater Recharge Utilizing Remote Sensing and GIS Methods

The indiscriminate use of groundwater and its overexploitation has led to a significant decline in groundwater resources in India, making it essential to identify potential recharge zones for aquifer recharge. A study was conducted to determine such potential recharge zones in the Nandhour-Kailash River watershed. The study area included 1481 streams divided into 12 sub-basins (SWS). The results show that the downstream Saraunj sub-basins (SWS-11) and Odra sub-basins (SWS-12) were high priority and required immediate soil and water conservation attention. Sub catchments Lobchla West (SWS-4), Deotar (SWS-5), Balot South (SWS-8), Nandhour (SWS-9), and Nakoliy (SWS-10) had medium priority and were designated for moderate soil erosion and degradation. In contrast, sub-catchments Aligad (SWS-1), Kundal (SWS-2), Lowarnala North (SWS-3), Bhalseni (SWS-6), and Uparla Gauniyarao (SWS-7) had low priority, indicating a low risk of soil erosion and degradation. Using the existing groundwater level data, the potential map of groundwater was validated to confirm its validity. According to the guidelines provided by the Integrated Mission for Sustainable Development (IMSD), the results of the groundwater potential zones for good to very good zones have been integrated at the slope and stream order. In a 120.94 km2 area with a slope of 0–5% in first-order streams, 36 ponds were proposed, and in a 218.03 km2 area with a slope of 15% in first- to fourth-order streams, 105 retention dams were proposed and recognized as possible sites for artificial groundwater recharge. The proposed water harvesting structure may aid in continuously recharging these zones and benefit water resource managers and planners. Thus, various governmental organizations can use the results to identify possible future recharge areas.

A new species of Dimeragrion Calvert, 1913 (Odonata: Zygoptera: Heteragrionidae) from Northwestern Brazil.

Dimeragrion Calvert, 1913 is a genus with five species, restricted to the Pantepui region. Here, we describe Dimeragrion baniwa sp. nov. (Holotype. ♂ (LABECO, N° 12276), BRAZIL, Amazonas, São Gabriel da Cachoeira, (0.017, -66.891, 81 m a.s.l.), first-order stream inside Terra Firme Forest, in lateral swamps: 29.xi.2021, C. C. Mendoza-Penagos & M. Gonçalves, leg.), the sixth species of the genus from 13 males and 3 females collected in the municipality of São Gabriel da Cachoeira in the Brazilian Amazon, located at the southern extreme of the Pantepui region. Additionally, we provide photographs of the diagnostic characters of the male and female, photographs of live specimens as well as information on their biology. Finally, identification keys are provided, as well as a distribution map of the species of the genus.

Response of stream macroinvertebrate communities to forest harvesting in the Piedmont region of North Carolina

Forest disturbances have significant effects on water quality and quantity, river geomorphology, and the ecology of receiving waterbodies. Riparian forests provide numerous functions for aquatic communities including retaining fine sediments and nutrients, controlling water temperature, and providing food sources and habitat for aquatic organisms. Forestry Best Management Practices (BMPs) use riparian forests as buffers to mitigate potential sources of disturbance to aquatic ecosystems from forest management. The objective of this study was to quantify the impacts of timber harvest on stream macroinvertebrates in the Piedmont region. We assessed the changes in macroinvertebrate communities and identified their relationships with specific hydrologic and water quality parameters. We used a paired watershed approach to quantify the response of watershed hydrology and water quality to clearcut forest harvesting with the use of BMPs in the Hill Demonstration Forest and Umstead Research Farm in central North Carolina. We sampled macroinvertebrates and monitored water quality in the first-order streams, and surveyed vegetation within riparian zones one year preharvest (2010) and four years postharvest (2011–2014). We found more sensitive species (indicated by biotic index classifications), scrapers, and Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa from the harvested watershed than in the reference watershed at the Umstead Research Farm site. No differences were detected between the reference and treatment watersheds at the Hill Demonstration Forest site. More sensitive species were present in watersheds with the highest pine basal area and in-stream total organic carbon (TOC) loads. More scrapers were present in watersheds with low hardwood basal area, high stream flow, and more vines. EPT abundance was higher in watersheds with high stream flow, large pine trees, and thick leaf litter layer. EPT abundance was lower in watersheds with large hardwood trees and high TOC loads. Overall, sensitive species, scrapers, and EPT abundance were lower in the Umstead Research Farm reference watershed than in any other watershed. We conclude that, in contrast to similar studies in the region, clearcut harvesting with the use of BMPs did not cause detectable negative effects on macroinvertebrate communities. Moreover, water quality as determined by macroinvertebrates may even be improved in some cases following clearcutting. This study provides a better understanding of how macroinvertebrate communities in Piedmont streams change after harvesting and what watershed characteristics may be driving these changes. This information is useful in characterizing macroinvertebrates in headwaters in the Piedmont, and helps land managers protect aquatic resources across the region.

A Bibliometric Overview of the International Airports and Airlines ‘IAA’ Topic in Journals and Scientific Community

Background: The purpose of this study is to provide an assessment of international airports and airlines, ‘IAAs’, and to organize and classify the literature on air transport to stage the importance of this topic and encourage future research in the projection of the aviation and tourism sectors. Methods: It is a bibliographic study, and this work focuses on IAA documents published in major international journals, conferences, and books from 2000 to 9 June 2021; this topic is scattered across various journals and has secondary data in many disciplines. Results: The findings suggest a new paradigm applied to the IAA topic and are classified in four first-order research streams: airports; airlines; connectivity; and competition. This study identifies new challenges and opportunities for researchers, airport and airline operators, and stakeholders to make better future decisions. Conclusions: There is no agreement on an explicit definition of the IAA concept that captures the true nature of this topic. For this reason, this article is innovative in the new IAA concept and in how it will possibly change the theoretical frameworks in future scientific research in the aviation and tourism sectors. This study has been needed to better understand the effectiveness, projection, and different business strategies to be adopted by researchers and organizations in the aviation and tourism future.

Extreme climatic events alter the aquatic insect community in a pristine German stream

As a result of ongoing climate change, extreme climatic events (ECEs) are expected to become more frequent and severe. The high biodiversity of riverine ecosystems is susceptible to ECEs, especially to water temperature (extreme heat and extreme cold) and discharge-related (flood and drought) events. Long time series are needed to unravel the effects of ECEs on ecological communities. Here, we used 20 years (1986–2005) of unusually high-resolution data from a pristine first-order stream in Germany. Daily recordings of species-level identified aquatic insect (Ephemeroptera, Plecoptera, Trichoptera: EPT) emergence, water temperature and discharge data were used to examine the effects of four types of ECEs (extreme heat, extreme cold, flood, and drought events) on insect abundance, common taxonomic diversity metrics, and selected traits after five different time lags (2 weeks, 1, 3, 6, and 12 months). Extreme heat events increased from 1.8 ± 1.9 SE events per year before 2000 to 5.3 ± 1.9 SE events per year after 2000. Water temperature-related ECEs restructured the EPT community in abundance, species richness, and traits (community temperature index: CTI, and dispersal capacity metric: DCM). The strongest effects on the EPT community were found when it was exposed to multiple ECEs and 1 and 3 months after an ECE. The changing frequencies and durations of ECEs, especially the increasing frequency of extreme heat events and the negative cumulative effects of ECEs, paint a worrisome picture for the future of EPT communities in headwater streams. High-resolution, long-term data across sites is needed to further disentangle the effects of different ECE stressors.

The Trichoptera of Panama XX. Six new microcaddisflies (Trichoptera: Hydroptilidae) and two new country records

Six new species of microcaddisflies (Trichoptera: Hydroptilidae) are herein described and illustrated: Cerasmatrichia armitagei sp. n., Metrichia hocica sp. n., Neotrichia majagua sp. n., N. solapa sp. n., Ochrotrichia latigiza sp. n., and O. ngabebuglea sp. n. These species were collected in western Panama from the Río Majagua watershed descending from Volcán Barú and Quebrada Martínez, a first-order stream in the Río Guabo watershed of the Bosque Protector Palo Seco. Metrichia quadrata (Flint, 1972) and Ochrotrichia filiforma Flint, 1972 are recorded for the first time from Panama. Two recently described species, Metrichia trebeki Harris and Armitage, 2019 and Ochrotrichia alma Thomson and Armitage, 2021 are reported for the second time from the country. The Republic of Panama now has 487 species of caddisflies distributed among 15 families and 56 genera. http://www.zoobank.org/urn:lsid:zoobank.org:pub:C98A88C2-2626-41E5-B294-0DBA6135AF67

Salamander Movement Propensity Resists Effects of Supraseasonal Drought

Movement can act as an effective strategy used by amphibians to avoid detrimental environmental conditions, particularly drought. However, due to the unpredictable nature of droughts, evaluating the patterns and consequences of movement has rarely been investigated. In 2007–2008, the southeastern United States experienced a supraseasonal drought that resulted in 110 yr low flow levels among the first-order streams. In this study, 61 months of mark–recapture data collected from one first-order stream were used to examine the effects of drought on the movement frequency distribution, survival, and growth rates of adult Desmognathus fuscus (Northern Dusky Salamander). We hypothesized that salamanders would demonstrate a higher propensity to move during supraseasonal drought conditions and that moving salamanders would experience higher survival and growth rates. We found that salamanders were more likely to move immediately after the drought compared to the pre-drought and drought conditions. Although movement frequency was low during the drought, survival was higher for individuals who moved during drought conditions in comparison to individuals who remained in their original capture location. Although our model did not detect a trend, salamanders experienced slightly higher growth in the post-drought conditions compared to drought and pre-drought conditions. In addition, during the post-drought, salamanders that moved had slightly higher growth rates compared to salamanders who remained in their original capture location. Our results suggest that adult salamanders were potentially displaying an adaptive movement strategy to resist drought conditions by moving away from affected (i.e., dry) areas within the study stream. In addition, movement was likely utilized to access replenished resources in other areas after the severe effects of the drought ended. Therefore, both in-stream and riparian barriers that impede movement may inhibit resilience of stream amphibians during severe droughts.

Catchment-scale deer exclusion changes longitudinal patterns of macroinvertebrate communities through soil runoff mitigation

Deer overpopulation is occurring worldwide, and deer-induced soil runoff into streams increases levels of suspended sediment and fine sedimentation. While deer-induced fine sedimentation in depositional habitats including first- and fourth-order streams is known to alter macroinvertebrate communities, effects of drifting suspended sediment in erosional habitats between the stream orders are poorly understood. Here, habitat and macroinvertebrate community structures in first- to third-order streams were compared between deer-excluded and grazed catchments of a Japanese headwater system. Fine sediment cover on the streambed was significantly greater in the grazed catchments than the deer-excluded catchment only for first-order streams, while macroinvertebrate community structure differed distinctly between the deer-excluded and grazed catchments at all stream orders. Burrowing collector-gatherers, which inhabit fine streambed sediments, were less abundant in first-order streams in the deer-excluded catchment than the grazed catchments, while clinging collector-filterers, which are vulnerable to suspended sediment inputs, were more abundant in second- and third-order streams of the deer-excluded catchment than the grazed catchments. These results suggest that the effect of deer exclusion on stream ecosystems varies with longitudinal changes in sediment deposition and transport capacity. Hydro-geomorphological processes are thus fundamental to assessing the restoration of forest-stream ecosystems, particularly in spatiotemporally dynamic headwater systems.

Quantifying excess heavy metal concentrations in drainage basins using conservative mixing models

High concentrations of heavy metals and other pollutants in river sediments can have detrimental effects on the ecosystem and humans. The composition of river sediments throughout drainage basins therefore provides important information for environmental monitoring. An obvious first step for using river sediment compositions for monitoring is to quantify natural baseline concentrations. Once baselines have been quantified, it is straightforward to compare them to observations to identify excesses generated by, for example, anthropogenic inputs. In this study a new strategy for mapping element concentrations along rivers from discrete geochemical observations upstream is presented. We demonstrate our approach in a case study of the Clyde drainage basin in western Scotland, UK. First, continuous baselines are generated using simple forward models that conservatively mix source region concentrations along drainage networks. 1185 measurements of elemental concentrations from first-order streams are used to parameterise the source region. The calculated baselines are then compared to concentrations measured at 60 localities along the main channel of the Clyde river. For a range of major and trace elements (e.g., Mg, Sr, K, Mn), the downstream observations are in close agreement with baseline concentrations predicted by conservative mixing models. However, some heavy metal concentrations (Pb, Cu, Zn) tend to exceed predicted baseline concentrations. Therefore, the second part of our approach calculates element concentrations in source areas required to match the observed Pb, Cu and Zn concentrations measured along the river. An inverse approach is used to ‘unmix’ the observed concentrations utilising, again, a conservative mixing model. Model resolution is determined by the spatial distribution of the data. Resultant calculated natural baselines and heavy metal concentrations along the river can easily be compared to estimate excesses. We tentatively suggest that anthropogenic input to sediment composition along the river is equivalent to annual fluxes of 9.7, 1.5 and 5.7 t (106 g) of Pb, Cu and Zn, respectively.

Microbial source tracking to elucidate the impact of land-use and physiochemical water quality on fecal contamination in a mixed land-use watershed

Escherichia coli has been widely used as a fecal indicator bacterium (FIB) for monitoring water quality in drinking water sources and recreational water. However, fecal contamination sources remain difficult to identify and mitigate, as millions of cases of infectious diseases are reported yearly due to swimming and bathing in recreational water. The objective of this study was to apply molecular techniques for microbial source tracking (MST) to identify sources of fecal contamination in a representative mixed land-use watershed located in the Appalachian Mountains of the United States of America (USA). Monthly samples were collected over one year at 11 sites, including the confluence of key first-order streams in the study watershed representing distinct land-use types and anticipated fecal sources. Results indicated that coupled monitoring of host-specific MST markers with the FIB E. coli effectively identified sources and quantified fecal contamination in the study watershed. Human-associated MST markers were abundant primarily at developed sites, suggesting septic or sewer failure is a key source of fecal input to the watershed. Across the dataset, samples positive for E. coli and human MST markers were associated with a higher pH than those samples from which each target was not detected, thereby suggesting that acid mine drainage in the watershed likely contributed to inactivation or loss of culturability in E. coli. In addition, this research provides the first evidence that the BacCan-UCD marker is present in fox feces and can influence MST results in areas where substantial wildlife activity is present. Identifying the sources of fecal contamination and better understanding the impact of in-stream physiochemistry throughout this study will help to develop sustainable and effective watershed management plans to control fecal contamination to protect drinking water sources and recreational water.

Achieving fast interfacial solar vapor generation and aqueous acid purification using Ti3C2Tx MXene/PANI non-woven fabrics.

Acid rain is a worldwide problem because of the emission of acidic gases into the atmosphere, leading to the acidification of first-order streams and aggravation of fresh water shortage. Therefore, it is of great importance to develop an environmentally friendly method for removing acid from water. Herein, an advanced technology that can achieve aqueous acid purification using solar energy is realized with Ti3C2Tx MXene/polyaniline (PANI) hybrid non-woven fabrics (MPs) through interfacial solar vapor generation, with PANI acting as an acid absorber through the doping process. Benefiting from the porous structure and crumpled micro-surface of MPs, a high evaporation rate of 2.65 kg m-2 h-1 with an efficiency of 93.7% can be achieved under one-sun illumination. Moreover, MPs present an even higher evaporation rate of 2.83 kg m-2 h-1 in high concentration aqueous acid and can generate clean water with a pH higher than 6.5. More importantly, thanks to the unique reversible doping process of PANI, when used as an aqueous acid purifier, MPs show good stability and reusability after dedoping. Our work sheds light on an efficient strategy for dealing with aqueous acid and acid rain.

Ecological aspects of Rhinoclemmys punctularia punctularia (Testudines: Geoemydidae) in two localities in northern Brazil

ABSTRACT Rhinoclemmys punctularia punctularia is the only turtle of the family Geoemydidae with part of its range in Brazil. The species is semi-aquatic and widely distributed across the Amazon basin but is still poorly studied. We evaluated aspects of the population structure, habitat use, seasonal activity, and diet of the species during one year, from the beginning of the rainy season to the end of the dry season, in two headwater localities in the Tocantins and Tapajós river basins, in the state of Pará, Brazil. We captured 45 individuals, 14 in the Tocantins basin and 31 in the Tapajós basin. The size-class frequency distributions of captured individuals did not differ between the two samples. The turtles were most frequently captured in first-order streams, followed by lentic (third-order dammed streams) and second-order streams. The capture rate did not vary significantly between sampling periods (start and peak of the rainy season; start and end of the dry season). The trapping effort to capture a single individual was much higher in the Tapajós basin (1,215 trap-hours) than in the Tocantins basin (136 trap-hours). Overall, the low capture rates confirm the secretive nature of the species in Amazonia and its apparent rarity. The individuals analyzed in this study consumed mainly plants.

Fusing International Business and Marketing: A Bibliometric Study

This study aimed to provide an assessment of marketing on international business and to organize and classify the literature on marketing in order to clarify the importance of this tool and encourage future research in the projection of international business marketing (IBM) and the power of the ubiquity of this tool in the hands of the users. It is a bibliometric study, and this work focused on international business and marketing articles published in major international marketing, expansion, strategies, and business journals from 2000 to 2020; this topic is scattered across various journals and second data in many disciplines. The investigation reviewed and collected data on the specific paradigm of research that discusses, investigates, and evaluates the topic of IBM. The results showed a new paradigm applied to the topic of IBM and classified it into four first-order research streams: academic research, international business, international development strategies, and customers. The contribution of this study is important in order to identify new challenges and opportunities for marketers, researchers and international companies and in terms of disentangling existing contradictions, applying a new theoretical framework to make better future decisions by large companies, and providing a higher quality to new research in the context of IBM.