Distribution Of Fauna Research Articles

Diversity and Abundance of Aquatic Insect Fauna in an Urban Freshwater Lake, Hatirjheel, Dhaka, Bangladesh

Freshwater lakes are a crucial component of the urban ecology and offer several direct and indirect advantages to its people. Habitat degradation of native insects has happened because of development activities and unscientific natural resource management. As a consequence, many insects of freshwater lakes are now rare and endangered. A research was conducted to find out the abundance, variety and distribution of aquatic insect fauna in an urban freshwater lake, Hatirjheel, Dhaka during November 2015 to February 2016. A total of 3255 individuals of water insects comprising of 11 species and 31 genera under 20 families belonging 5 orders were recorded. The order Hemiptera contained the highest abundance (38.71%) including 7 families and 12 genera containing 5 species, while Trichoptera had the lowest (6.45%) including 2 families and 2 genera. The dominating species in the lake was Micronecta haliploides. The maximum 19 aquatic insect species were reported in the lake's vegetation-rich section near the Mouchak-Moghbazar flyover (Spot 1), whereas a minimum of 5 species were found near the Modhubagh bridge road (Spot 2). Species diversity index (H′ = 2.74), species richness (SR = 8.54), aquatic insect distribution evenness (J′ = 0.80), community dominance (CD = 46.94%), and Simpson’s index (λ = 0.17) were analyzed in this study to determine the diversity, abundance, distribution and dominance of aquatic insect fauna in this lake. Bangladesh J. Zool. 50(3): 363-372, 2022

Danian-Ypresian dinocyst biostratigraphy, fish fauna and depositional environment of the Akli Formation, Barmer Basin, western India

ABSTRACT Herein, we present a diverse record of dinoflagellate cysts from the lignite-associated sedimentary succession (belonging to the Akli Formation) at Sonari Lignite Mine, Barmer Basin, Rajasthan State, western India. The dinoflagellate cyst assemblage implies a Danian to Ypresian age for the investigated succession and argues that the deposition of lignitic sequences along India’s western margin is not coeval. We also identify two vertebrate (dominantly fish-yielding) units within the studied Akli Formation succession. The Ypresian fish genera (mainly represented by dental remains) include Ginglymostoma, Jaekelotodus, Brachycarcharias, Pycnodus and Myliobatis while the Selandian-Thanetian fish dental remains include Dasyatis. A discontinuous distribution of fish fauna during the early Paleogene (based on the temporal and spatial data) within the lignite-associated sedimentary successions of western and north India allows us to infer the prevalence of separated realms with variably restricted palaeoenvironmental conditions. Overall, the faunal evidence is indicative of dominantly estuarine to shallow marine conditions with enhanced freshwater influence during the Thanetian as compared to the Danian. Our study also argues in favour of the earliest appearance of dinoflagellate cyst Apectodinium in the near-equatorial region of the Tethys Ocean during the early Paleocene. (within Danian).

Composition and vertical distribution of agricultural soil Macrofauna community after an extreme high temperature event in the summer of 2022

Extreme high temperature (EHT) events are becoming more frequent and prolonged due to global climate change. Predicting the effects of EHT events on agricultural soil fauna remains a major challenge. In order to assess the response of community composition and vertical distribution of soil fauna to EHT events, this study investigated the soil macrofauna communities in facility agricultural farmlands at the end of an EHT event in East China in 2022 and eighteen days after. The results showed that the taxonomic richness and abundances of the soil macrofauna community were reduced eighteen days after the EHT event. However, changes in abundance were taxonomically dependent: individuals of ants (Pheidole indica), centipedes (Himantariidae) and crickets decreased significantly, while Enchytraeidae and earthworms increased. Soil water content was an important factor determining taxonomic richness at the end of the EHT event and the abundance of earthworms eighteen days after the EHT event. The maximum values of taxonomic richness and abundance of the soil macrofauna community were observed in the surface layer (0–10 cm) at the end of the EHT event and eighteen days after. Earthworms burrowed into the deeper layer at the end of the EHT event, but moved to the surface layer eighteen days after the EHT event. These results showed that most soil fauna taxa experienced adverse effects posed by EHT events, while the earthworm and Enchytraeidae had abilities to increase their abundances rapidly by EHT events. This study suggests that soil water content and vertical distribution should be considered when assessing the impact of an EHT event on soil biodiversity.

Habitat and benthic fauna of the Wallaby-Cuvier escarpment, SE Indian ocean

The Wallaby-Cuvier Escarpment is a 700 km long, NW-SE trending linear geological feature that marks the southern boundary of the Cuvier Plateau. The Plateau rises from the adjacent 5500 m deep abyssal plain to a topographical high of 3000 m, approximately 450 km off the coast of Western Australian. In 2021, a 50 km long segment of the escarpment, covering an area of 1700 km2, was mapped by a high-resolution full-ocean depth multibeam echosounder. The habitat of the study area was explored during two video surveys undertaken using the crewed submersible Limiting Factor. Using Benthic Terrain Modeler (BTM), we classified the seabed into five geomorphological classes; flat plains, depressions, broad slopes, steep slopes, and crest. Video footage was used to classify habitat types and to record benthic megafauna occurrences which revealed highly heterogeneous and rapidly changing habitats. Six habitats were proposed based on the nature of geomorphology, slope, and substrate textures. A total of 202 organisms comprising 52 morphotaxa were scored during 198 min of survey that included at least eight phyla and 29 families. Despite a high number of morphotaxa, the total abundance of organisms is considered low which we attribute to oligotrophic surface waters. However, the distribution of organisms and their feeding strategies were well-aligned with habitat type. This study documents faunal distribution and habitat diversity of a rarely explored type of deep-sea geomorphological feature, and in a largely unexplored area and depth of the Indian Ocean.

An overview of the Romanian Meessiidae, Eriocottidae and Tineidae (Lepidoptera, Tineoidea) summarizing the current knowledge in an updated and annotated checklist

An up-to-date reassessment of the Romanian Meessiidae, Eriocottidae and Tineidae fauna is presented. In the Romanian fauna a total of 7 Meessiidae species had been given, but only 6 species, all in Eudarcia Clemens, 1860, are currently accepted. Eudarcia balcanicum (Gaedike, 1988) is recorded in Romania for the first time and a photograph of the adult male is provided for the first time. The presence of E. pagenstecherella (Hübner, 1825) in Romania requires confirmation. The Eriocottidae is represented by only one species. From the total of 83 Tineidae species ever recorded, 76 are currently accepted for the Romanian fauna, 9 of them are the first records: Nemapogon falstriella (Haas, 1881), Matratinea rufulicaput Sziráki & Szőcs, 1990, Tinea basifasciella Ragonot, 1895, Niditinea truncicolella (Tengström, 1848), Monopis jussii Kaila, Mutanen, Huemer, Karsholt & Autto, 2020, M. weaverella (Scott, 1858), M. neglecta Šumpich & Liška, 2011, Pelecystola fraudulentella (Zeller, 1852) and Wegneria panchalcella (Staudinger, 1871). The presence of Nemapogon quercicolella (Zeller, 1852) needs confirmation. Two species, Tenaga nigripunctella (Haworth, 1828) and Monopis christophi Petersen, 1957, are deleted from the checklist in this paper, five others were deleted earlier. Of the three families treated a total of 29 additions and other corrections are provided for the regional distribution of the Romanian fauna. We recommend that the information about the Meessiidae and Tineidae in the latest Romanian checklist (Rákosy & Goia 2021) is replaced by that in this publication

Long-term changes in the composition and distribution of the Hungarian bumble bee fauna (Hymenoptera, Apidae, Bombus)

One of the most important pollinator taxa is Bombus (Hymenoptera, Apidae), the genus of bumble bees, since they are important, often specialized, pollinators of many plants. As a result of climate change, warming winters and changes in landscape structure, the distribution and frequency of Bombus species is constantly changing. To develop appropriate protection strategies, it is essential to monitor them and update the occurrence and threat status of the species. The last review of the distribution of Bombus species in Hungary was completed 20 years ago. Here we present updated distribution maps based on published data from the last 20 years together with unpublished data collected in 2018–2021. Based on the new data, we examine changes in the last two decades. In the case of 9 species further studies should be carried out to confirm the presence of stable populations, while 3 species are recommended for protection by law in Hungary. Seven species showed increasing frequency, B. argillaceus and B. haematurus.

An examination of how climate change could affect the future spread of Fusarium spp. around the world, using correlative models to model the changes

Climate change is predicted to have a significant impact on the geographic distribution of various flora, fauna, and insect species by expanding, contracting, or shifting their suitable climate environment. The plant pathogenic fungus Fusarium is known for causing crop diseases like blight, root and stem rots, and wilts, making it the most significant mycotoxigenic genus in weeds and food across various climatic zones worldwide. In this study, we hypothesize that crop diseases caused by Fusarium spp. will increase across all four corners of the world by 2050 and 2070 in response to future climate conditions. A series of correlative species distribution models (SDMs), including a generalized linear model (GLM), maximum entropy (MaxEnt), generalized boosting model (GBM), and surface range envelope, were employed to project and compare how the niche of Fusarium spp. will change from the present time to 2050 and 2070 under two Climate Change Representative Concentration Pathways (RCPs) of 8.5 and 4.5 (scenarios of high and low greenhouse gas emissions, respectively). Our approach (the ensemble predictions of 4 SDMs) minimizes the uncertainty (differences) of the projection results from each one of the models. The findings of this study have global implications because Fusarium spp. are associated with host species that are present on major continents such as Asia, Europe, Australia, and North and South America. The information gathered could be beneficial to farmers and planners when creating strategies to prevent the proliferation of Fusarium spp. as well as calculating the expenses associated with using pesticides to minimize contamination and increase yields.

Pemahaman Peta Konsep dan Miskonsepsi Siswa SMA Kelas X Semester 2 pada Materi Keanekaragaman Hayati

This descriptive research is motivated by the many problems that arise due to the low competence of students' knowledge in learning Biology on Biodiversity material in grade 10 senior high school semester 2 which is closely related to misconceptions. This study aims to analyze concept maps and find out which sub-materials have the most misconceptions experienced by students in the subject of enriching life in grade 10 Semester 2 with material topics which include: the concept of biological conservation, diversity levels (genes, species and ecosystems). ), as well as the distribution of flora and fauna in Indonesia. This research is a qualitative descriptive study with the data collection technique that the author uses is to use literature studies from several sources related to the misconceptions of 10th grade high school students semester 2 on biodiversity material. Based on data obtained from several sources related to misconceptions experienced by students, where the most dominant sub-material students experience misconceptions is located on the concept of conserving biodiversity, conserving biodiversity at the level (genes, species and species), and sub-material trade and distribution of flora and fauna in Indonesia. The conclusion from the results of this study is a misconception of biodiversity material caused by differences in learning support reference books.

Implication of middle Eocene to early Miocene ostracodes from the N. El Faras-1X Well, Qattara Depression, Egypt, for paleobathymetry and paleobiogeographic reconstruction

The subsurface middle Eocene - early Miocene succession in the N. El Faras - 1X Well, drilled in the Qattara Depression at the northern part of the Western Desert, Egypt (Southern Tethyan Province, STP), was studied for its ostracode content to infer changes in paleobathymetry as well as paleobiogeographic reconstructions. This succession is composed mainly of three lithostratigraphic units, as the upper part of the Apollonia Formation (middle to late Eocene), the Dabaa Formation (late Eocene and Oligocene) and the lower part of the Moghra Formation (early Miocene). The stratigraphical distribution, paleoenvironmental and paleobiogeographical significance of the ostracode faunas from the Oligocene interval of the study area are documented for the first time. Fifty seven ostracode species belonging to 36 genera were identified in this succession. Among them, two new species were described. The vertical distribution of these ostracode species enabled the recognition of seven local biozones. Qualitative and quantitative statistical analysis of ostracode associations revealed a depositional depth ranging from the inner to outer neritic setting. Considering the CONISS cluster analysis, six ecozones were established. During the middle and late Eocene, the paleobiogeographical affinities of the Egyptian ostracodes from N. El Faras-1X× Well succession with that of the Southern Tethyan countries suggest a direct connection between Egypt and the countries of the Southern Tethyan Province. This connection facilitated the dispersal and exchange within this province. The low ostracode similarity between the STP and the Northern Tethyan Province (NTP) suggests a slight connection and exchange between them. The in common occurrence of these ostracodes with that of Somalia is attributed to the connection between the STP and Somalia via the Tethyan Seaway, which facilitated the dispersal and exchange of the middle Eocene ostracodes. The similarity between the Egyptian ostracodes (STP) and that of South America and the Caribbean Sub-Province indicates a direct connection between those provinces across the Gibraltar Strait and through the North Equatorial Oceanic Water Current during that time. During the Oligocene, the low ostracode similarity between the STP and the NTP may be attributed to a more or less restricted connection. Also, the low similarity indicates a continuation of the mild connection between the STP and the South America and Caribbean Sub-Province across the Gibraltar Strait and through the North Equatorial Current. During the early Miocene, the similarity of the recorded ostracodes of the STP with that of the NTP suggests a continuous connection between the two provinces. Also, there was a connection between the South America and Caribbean Sub-Province and the North American Province through the North Equatorial Current and the warm Gulf Stream within the Caribbean Sea.

Anthropogenic predictors of varying Holocene occurrence for Europe's large mammal fauna.

Understanding how species respond to different anthropogenic pressures is essential for conservation planning. The archaeological record has great potential to inform extinction risk assessment by providing evidence on past human-caused biodiversity loss, but identifying specific drivers of past declines from environmental archives has proved challenging. We used 17 684 Holocene zooarchaeological records for 15 European large mammal species together with data on past environmental conditions and anthropogenic activities across Europe, to assess the ability of environmental archives to determine the relative importance of different human pressures in shaping faunal distributions through time. Site occupancy probability showed differing significant relationships with environmental covariates for all species, and nine species also showed significant relationships with anthropogenic covariates (human population density, % cropland, % grazing land). Across-species differences in negative relationships with covariates provide ecological insights for understanding extinction dynamics: some mammals (red deer, aurochs, wolf, wildcat, lynx, pine marten and beech marten) were more vulnerable to past human-environmental interactions, and differing single and synergistic anthropogenic factors influenced likelihood of past occurrence across species. Our results provide new evidence for pre-industrial population fragmentation and depletion in European mammals, and demonstrate the usefulness of historical baselines for understanding species' varying long-term sensitivity to multiple threats.

Spatial and temporal environmental heterogeneity induced by internal tides influences faunal patterns on vertical walls within a submarine canyon

Vertical walls of submarine canyons represent features of high conservation value that can provide natural areas of protection for vulnerable marine ecosystems under increasing anthropogenic pressure from deep-sea trawling. Wall assemblages are spatially heterogeneous, attributed to the high environmental heterogeneity over short spatial scales that is a typical feature of canyons. Effective management and conservation of these assemblages requires a deeper understanding of the processes that affect faunal distribution patterns. Canyons are recognised as sites of intensified hydrodynamic regimes, with focused internal tides enhancing near-bed currents, turbulent mixing and nepheloid layer production, which influence faunal distribution patterns. Faunal patterns also respond to broad-scale hydrodynamics and gradients in water mass properties (e.g. temperature, salinity, dissolved oxygen concentration). Oscillating internal tidal currents can advect such gradients, both vertically and horizontally along a canyon's walls. Here we take an interdisciplinary approach using biological, hydrodynamic and bathymetry-derived datasets to undertake a high-resolution analysis of a subset of wall assemblages within Whittard Canyon, North-East Atlantic. We investigate if, and to what extent, patterns in diversity and epibenthic assemblages on deep-sea canyon walls can be explained by spatial and temporal variability induced by internal tides. Vertical displacement of water mass properties by the internal tide was calculated from autonomous ocean glider and shipboard CTD observations. Spatial patterns in faunal assemblage structure were determined by cluster analysis and non-metric Multi-Dimensional Scaling plots. Canonical Redundancy Analysis and Generalised Linear Models were then used to explore relationships between faunal diversity and assemblage structure and a variety of environmental variables. Our results support the hypothesis that internal tides influence spatial heterogeneity in wall faunal diversity and assemblages by generating both spatial and temporal gradients in hydrodynamic properties and consequently likely food supply.

Characteristics of Fragments of Woodland and Their Influence on the Distribution of Soil Fauna in Agricultural Landscape

Fragments of woodland represent important natural and semi-natural elements that contribute to ecological stability and biodiversity in a landscape. In the Czech Republic, they are part of the Territorial System of Ecological Stability (TSES), which consists of bio-centers, bio-corridors, and interaction elements. The presence of fragments of woodland is of growing importance in the agricultural landscape, where they provide effective protection against soil erosion and serve as a refuge for many animals, whose presence is crucial in maintaining essential ecosystem functions. A functioning ecosystem is especially important in intensively farmed landscapes, which are exposed to frequent and heavy disturbance. Our aim was to evaluate the influence of certain habitat characteristics of fragments of woodland on the activity-density and species richness of selected groups of soil invertebrates (ground beetles, spiders, harvestmen, centipedes, millipedes, and isopods). The research was conducted in the agricultural landscape of South Moravia (Czech Republic) in the summers of 2016–2017, for which we used pitfall traps to collect soil invertebrates on preselected fragments of woodland. The results highlight a wide range of habitat preferences of individual groups of invertebrates, wherein it is not possible to clearly determine the most favorable environmental conditions for all organisms. Consequently, the priority should be to maintain the highest possible degree of heterogeneity among natural and semi-natural features, including with respect to their surrounding landscape. In addition, we found that due to their small size and width, fragments of woodland that are not included in the concept of bio-centers and bio-corridors can similarly support the activity-density and diversity of soil fauna.

Spatio-temporal distribution of benthic fauna in mangrove areas in the Bay of Vitória estuary, Brazil

The diversity and abundance of fauna may reflect the condition of the mangrove and be used as an indicator of habitat changes, thus the aim of this study is to analyze the distribution of fauna in mangroves under the influence of urban occupation, evaluating the types of forests (basin and fringe), sampling points along the estuary and effects of climatic seasonality through population parameters of crustacean and mollusc epifauna and infauna. Furthermore, this work assesses the influence of environmental variables on the diversity and composition of those communities in the studied forests. For the epifauna, three quadrats of 1 m2 were delimited at each point and the organisms were identified and quantified. For infauna, three sediment samples were collected at each point using a cylindrical sampler and os organisms retained was identified. The environmental variables analyzed were: salinity, standing crops and organic matter in the sediment and granulometry and vegetation data. There was a differentiated distribution of species between of fringe and basin, related to organic matter and standing crops as a consequence of the flooding frequency. The molluscs represented the community with the best response associated with these factors, an aspect justified by their eating and physiological habits. Crustaceans exhibited significant differences with higher diversity and richness in the rainy period, when their reproductive processes occur. For the plant community, Laguncularia racemosa was dominant in the basin and Rhizophora mangle in the fringes, also explaining the differences in the spatial distribution of the fauna. Data from ecological descriptors of crustaceans showed a positive correlation with the areas closest to urban occupation, while molluscs and infauna had a positive correlation with greater structural development of the forest. The mangrove in the Bay of Vitória, although with high anthropogenic pressure, has a diversified fauna and is integrated with vegetation and environmental factors.

Epizootological monitoring of rabbit parasitoses on the territory of Ukraine

One of the conditions for successfully managing rabbit breeding is ensuring the epizootological well-being of farms concerning invasive animal diseases. Helminthiases, protozooses, and acaroses cause significant economic damage to the industry due to a decrease in the biological value of rabbit meat and skins, a delay in growth, development, and a decrease in the growth of young animals, as well as their death. Carrying out epizootic monitoring and assessment of the epizootic situation in different regions of Ukraine is one of the main preventive measures, which, based on the results of the study of the epizootic state, analysis of veterinary reports, and the results of laboratory tests, will allow effective treatment and prevention of invasive diseases in rabbit farms. The purpose of the work was to conduct monitoring studies of the epizootic situation regarding rabbit parasitoses in the territory of some areas of Ukraine. It was established that the total incidence of domestic rabbits by parasitoses was 36.27 %. The weight of infestations caused by the simplest organisms was the highest, reaching 81.96 %. The specific weight of infestations caused by acariform mites, nematodes, and cestodes was insignificant and amounted to 9.88 %, 7.3 %, and 0.86 %, respectively. Among the protozooses – eimeriosis, nematodoses – pasalurosis, cestodoses – cysticercosis, acaroses –psoroptosis were found in rabbits. High indicators of the extensiveness of animal invasion were established for eimeriosis (50.23 %). Smaller values of infestation of rabbits were found for psoroptosis (18.0 %) and pasalurosis (16.87 %). For pysiform cysticercosis, the extent of invasion was insignificant – 5.97 %. Indicators of the extensiveness of invasions in different regions of Ukraine ranged from 15.28 to 100.0 % for eimeriosis, from 4.35 to 100.0 % for pasalurosis, from 50.0 to 100.0 % for cysticercosis, and from psoroptosis 11.54 to 100.0 %. The obtained results of monitoring studies on the epizootic status of invasive rabbit diseases on the territory of Ukraine indicate the relevance and perspective of further studying the distribution of parasite fauna in the population of domestic rabbits, taking into account the climatic conditions of different regions, the way rabbits are kept, their age and season.

Changing palaeobiogeography during the Ordovician Period

Abstract Owing to the increasing availability of data for many fossil groups and a generally accepted palaeogeographical configuration, palaeontologists have been able to develop progressively more robust palaeobiogeographical scenarios for the spatial distributions of Ordovician marine faunas. However, most research in Early Paleozoic palaeobiogeography centres on data derived from extensively studied localities in North America and Europe. Thus, clear patterns are emerging of regional biogeography for these areas. However, the fragmentary nature of data from other regions hinders the development of a detailed understanding of palaeogeographical schemes of many clades at the global level. Provincial patterns are now available for several fossil groups, but the global coverage remains generally fragmentary. Palaeobiogeographical investigations were traditionally focused on better understanding of palaeogeographical scenarios and often employed quantitative analyses of faunal similarity. More recently palaeobiogeographical analyses have expanded to investigate questions such as the location and pace of speciation and macroevolution together with macroecological change. For example, studies on the evolution of speciation levels in the frame of the taxonomic radiation of the Great Ordovician Biodiversification are now available. Future investigations, including modelling, will provide more integrative, global patterns of provincialism, including the location of Ordovician biodiversity hotspots and the recognition of latitudinal diversity gradients.

Habitat Suitability and Conflict Zone Mapping for the Blue Bull (Boselaphus tragocamelus) across Nepal.

Rapidly changing environmental conditions (bioclimatic, anthropogenic, topographic, and vegetation-related variables) are likely to alter the spatial distribution of flora and fauna. To understand the influence of environmental variables on the Blue bull's distribution and to identify potential conflict zones, the habitat suitability analysis of the Blue bull was performed using ensemble modeling. We modelled the distribution of the Blue bull using an extensive database on the current distribution of the Blue bull and selected 15 ecologically significant environmental variables. We used ten species distribution modeling algorithms available in the BIOMOD2 R package. Among the ten algorithms, the Random Forest, Maxent, and Generalized linear model had the highest mean true skill statistics scores, ensuring better model performance, and were considered for further analysis. We found that 22,462.57 km2 (15.26%) of Nepal is suitable for the Blue bull. Slope, precipitation seasonality, and distance to the road are the environmental variables contributing the most to the distribution of Blue bull. Of the total predicted suitable habitats, 86% lies outside protected areas and 55% overlaps with agricultural land. Thus, we recommend that the future conservation initiatives including appropriate conflict mitigation measures should be prioritized equally in both protected areas and outside protected areas to ensure the species' survival in the region.

Fuzzy combined effect time quantity dependent data matrix for predicting phytal fauna distribution and diversity

Fuzzy logic can be used to analyse and classify flora and faunal diversity. It uses fuzzy logic to describe richness and complexity of plant and animal life. Fuzzy logic can identify patterns in data to better understand diversity of an ecosystem. This study used a fuzzy combined effect time quantity dependent data matrix to predict the distribution and diversity of phytal fauna in Erayamanthurai coast. The method involved the use of Initial Raw Data Matrix (IRDM), Average Quantity Dependent Data Matrix (AQDM), Refined Quantity Dependent Data Matrices (RQDMs) and Combined Effect Quantity Dependent Data Matrix (CEQDM). Results showed that the high number of fauna was recorded in sites at α = 0.75 level and the faunal ranges were medium at α = 0.5 level. Negative values in the sites of S2, S3, and S4 indicated that faunal composition in these sites was not preferred. This fuzzy combined effect time quantity dependent data matrix was able to predict the exact place that had more anthropogenic disturbance to disturb the diversity and distribution of phytal fauna.

Human-Induced Impact on the Distribution and Diversity of Benthic Macroinvertebrates and Fish Fauna in the Tropical Ikang River, Nigeria

Abstract South-eastern Nigeria’s tropical water ecosystems typically consist of mangrove swamps and riparian forests, both of which have become endangered in the last six decades. The purpose of this research was to determine the extent of human-induced impact and activities on the effect of water quality on the distribution and diversity of benthic macroinvertebrates and fish fauna in the Tropical River (Ikang). The river’s surface water, benthic macroinvertebrates, and fish fauna were sampled and identified to create a database of reference information. Twelve (12) species of benthic macroinvertebrates from two (2) phyla were identified. Station 1 had the highest benthic macroinvertebrate abundance of 58 (35.65%), while Station 3 had the lowest abundance of 52 (31.70%). Uca tangeri was the most abundant benthic macroinvertebrate with a percentage abundance of 28 (17.07%), while Dinocras sp., Macromia sp., and Gomphus sp. were the least abundant benthic macroinvertebrates with a percentage abundance of 3.66%. In addition, seven (7) fish species from six (6) families were identified. During the study, the family Claroteidae was the most abundant, while the family Carangidae was the least abundant. The temperature of the river had a positive correlation with the families Carangidae and Mugilidae, a negative correlation with the family Clupeidae, and no correlation with the family Claroteidae. Total dissolved solids (TDS) correlated positively with the families Carangidae, Mugilidae, and Clariidae, while conductivity correlated positively only with the family Sciaenidae and negatively with the families Carangidae, Mugilidae and Clariidae. The abundance and diversity of benthic macroinvertebrates and fish fauna were generally influenced by the physical and chemical characteristics of the water, the availability of food, and the extent of human impacts and activities. In order to ensure sustainable water quality and biodiversity conservation in our environment, it is necessary to manage the river and the surrounding ecosystem appropriately.

Benthic biogeographic patterns on the deep Brazilian margin.

The Brazilian continental margin (BCM) extends from the Tropical to the Subtropical Atlantic Ocean, with much of its seafloor within deep waters, supporting rich geomorphological features and under wide productivity gradients. Deep-sea biogeographic boundaries on the BCM have been limited to studies that used water mass and salinity properties of deep-water masses, partly as a result of historical under sampling and a lack of consolidation of available biological and ecological datasets. The aim of this study was to consolidate benthic assemblage datasets and test current oceanographic biogeographical deep-sea boundaries (200-5,000 m) using available faunal distributions. We retrieved over 4,000 benthic data records from open-access databases and used cluster analysis to examine assemblage distributions against the deep-sea biogeographical classification scheme from Watling et al. (2013). Starting from the assumption that vertical and horizontal distribution patterns can vary regionally, we test other schemes incorporating latitudinal and water masses stratification within the Brazilian margin. As expected, the classification scheme based on benthic biodiversity is in overall agreement with the general boundaries proposed by Watling et al. (2013). However, our analysis allowed much refinement in the former boundaries, and here we propose the use of two biogeographic realms, two provinces and seven bathyal ecoregions (200-3,500 m), and three abyssal provinces (>3,500 m) along the BCM. The main driver for these units seems to be latitudinal gradients as well as water mass characteristics such as temperature. Our study provides a significant improvement of benthic biogeographic ranges along the Brazilian continental margin allowing a more detailed recognition of its biodiversity and ecological value, and also supports the needed spatial management for industrial activities occurring in its deep waters.

Middle Cenozoic micromammals from Linxia Basin, Gansu Province, China, and their implications for biostratigraphy and palaeoecology

We report late Oligocene to late Pliocene micromammal assemblages from 19 localities of the Linxia Basin of Gansu Province, China. Abundant material (> 7000 specimens) includes members of Eulipotyphla, Chiroptera, Rodentia and Lagomorpha, and comprises 121 species arranged in 24 families. The Yagou assemblage (basal part of the Jiaozigou Formation) is one of the few early Late Oligocene micromammalian faunas known from China. The Galijia (Dongxiang Formation) and Yihachi (“Liushu” Formation) assemblages represent the richest and most productive middle and late Miocene micromammal faunas known from northwestern China. These middle Cenozoic faunas show a closely similar community structure and taxonomic composition, and a similar pattern of faunal turnover, with contemporary faunas throughout the Mongol-Xinjiang Region, implying the existence of a unified biogeographic zone. The discoveries contribute to the temporal ordering of individual fossil assemblages of northern China and help develop a framework for Cenozoic biostratigraphy and biochronology in central Asia. Our palaeoenvironmental analysis suggests change towards warmer and moister equable habitats of the late Oligocene to early and middle Miocene, followed by the onset of drier temperate shrub-steppe environments. The composition of extant families of micromammals that developed during the Neogene reflects a faunal distribution analogous to the Holarctic Region today and suggests a shared ecology.