Flowing Water Bodies Research Articles

Identification and quantification of microplastic particles in drinking water treatment sludge as an integrative approach to determine microplastic abundance in a freshwater river

Microplastic (MP) has been detected ubiquitously in freshwater systems. Until now MP sampling, however, is predominantly based on short-term net or pumping and filtration systems which can only provide snapshots of MP abundance; especially in flowing water bodies. To improve representativeness in the determination of MP occurrences in these aquatic compartments, an integrative approach that covers larger water volumes for a longer period of time is required. In this regard, surface water supplied drinking water treatment plants (DWTPs) represent an opportunity. In DWTPs, suspended solids from thousands of cubic metres of raw water are continuously removed over several hours and enriched in coagulation/flocculation and filtration processes. Our hypothesis was that MP is also removed to a full extent, like suspended solids, and that an integrative approach for identification and quantification in raw water can be derived from the analysis of MP in the treatment sludge. To prove this hypothesis, treatment sludge from a riverside DWTP (Warnow river, North-Eastern Germany) was analysed for MP > 50 μm. A sample purification protocol overcoming potential matrix effects caused by coagulants and flocculants was developed and validated. MP was analysed using micro-Raman spectroscopy. MP occurrence determined for the Warnow river was compared with in situ reference sampling using an established pumping and filtration system at relatively stable flow conditions. As result, the number of MP particles derived from treatment sludge was extrapolated to 196 ± 42 m−3 for the Warnow river and is statistically insignificantly different from 233 ± 36 m−3 identified by conventional water sampling. In addition, the polymer distribution and particles shape indicated the validity of the integrative concept. Consequently, the determination of MP abundance for freshwater systems based on DWTP treatment sludge represents an adequate method to estimate MP concentrations in flowing waters in an integrative way.

Macrospatial structure and biodiversity of bat communities (Chiroptera) of the European fauna in the forest-steppe habitat

Twelve bat species of seven genera of the family Vespertilionidae were studied in conditions of the Central Forest-steppe of Ukraine (Myotis nattereri, M. daubentonii, M. dasycnemе, Barbastella barbastellus, Plecotus auritus, Pl. аustriacus, Pipistrellus pуgmaeus, P. kuhlii, P. nathusii, Nyctalus noctula, N. leisleri, Vespertilio murinus, and Eptesicus serotinus). The data were collected during decade-long surveys (2007–2016) in the Central Forest-Steppe (Cherkasy, Kirovohrad, and Kyiv Oblasts, Ukraine) at 23 localities. The census route included 680 km walked along the surveyed territory. The species composition of different habitats was determined during faunal and indoor surveys, when a certain type of landscape changes to another, and also by comparing the species composition of communities in different types of habitats. For species diversity comparison, five types of habitats were selected: forest (W), towns and villages (A-W), wood lines and fields (F-W), wetland areas (A-W), and fores parks (W-P). The analysis of record localities of bats and the character of their biotopic distribution shows that most species prefer floodplains with trees (wetland areas (A-W) and forest parks (W-P)), where the maximum number of species was noted. Quite high diversity was also noted for settlements (T-W). Based on abundance, a noticeable decrease of the diversity index occurs during the transfer from the area of wetland types to fields and wood lines. Due to the character of differences between groups of local bat species, relative to spatial distribution of species on topical and trophic levels, the performed analyses helped us to outline four groups of species. The first group includes species united by open type habitats (N. noctula and N. leisleri). The second group comprises V. murinus, E. serotinus, P. pуgmaeus, and P. kuhlii, which are very hard to relate to a separate type of locality. The third group includes species that prefer closed habitats: M. nattereri, M. daubentonii, Pl. auritus, P. nathusii, and B. barbastellus. The fourth group comprises M. dasycnemе, a species that is relatively rare in the studied territory and is related to lakes and slow flowing water bodies.

Оценка экологического благополучия рек Среднего Урала в зонах с повышенной техногенной нагрузкой

Abstract. The purpose of our work was to assess the chemical composition and physicochemical properties of surface water bodies exposed to industrial enterprises and located in close proximity to agricultural land. The environmental condition of industrial regions is determined by the specifics of their development. Recently, vast territories of cities and agricultural lands have been subjected to a high degree of technogenic pollution, which is caused by excessive concentration of production and its continuous and long-term negative impact on natural complexes, which causes a sharp reduction in natural resource potential and its degradation [1, p. 200]. Methods. The article examined the ecological status of flowing water bodies in some areas of the Sverdlovsk region. Assessment of the ecological state of the rivers was assessed by physicochemical and chemical indicators, which included mineralization, hydrogen, and the concentration of salts of heavy metals. Results. During the study, we took water samples from 5 rivers flowing in areas with different technogenic loads. In the hot study, violations were identified by physico-chemical and chemical indicators. At the same time, excesses in mineralization were noted in the rivers of the Artinskiy district, indicators here ranged from 335, which refers to the average mineralization group up to 509 mg/dm3, which refers the river to the group of mineralization increased, almost all the rivers under study have a neutral reaction in terms of hydrogen value. The excess of MPC was noted in the rivers mainly cobalt, manganese, copper, nickel, lead and zinc, while the excess for various metals ranged from 1 to 32 MPC. Scientific novelty. As a result of the study, the most polluted of the rivers studied by us was determined, which is located in the zone of increased technogenic load and it is noted that the maximum concentration of pollutants falls on the Kamenskiy district.

Distribution characteristics of trifluoroacetic acid in the environments surrounding fluorochemical production plants in Jinan, China

Trifluoroacetic acid (TFA) is a ubiquitous and extremely stable contaminant in the ambient environment and may be discharged during fluorochemical production processes. However, the impacts of fluorochemical production on surrounding areas have seldom been evaluated. We focused on Jinan, the capital of Shandong Province, China, and measured TFA levels in water, soil, and air samples. Our results showed that the average TFA concentrations in flowing water bodies were lower than those in landscape water bodies. The average TFA concentrations in soils were significantly higher than the background concentration. As for atmospheric TFA levels, the mean concentrations in the gas phase were higher than those in the particle phase, and average daytime levels were slightly higher than nighttime levels. In addition, the quotient method was used to assess the ecological risk of TFA in water in Jinan. The ratio of pollutant environmental concentration to predicted no-effect concentration (PEC/PNEC) for TFA was greater than 1, indicating that TFA does potentially damage the aquatic ecosystem of Jinan. Our findings suggest that TFA pollution around fluoride production plants is a serious problem and that actions are required to avoid exacerbating the local ecological and environmental risks of TFA.

Mechanism of accelerated dissolution of mineral crystals by cavitation erosion

Cavitation, a phenomenon produced by a moving fluid, is ubiquitous in the water environment of the Earth’s surface and its related mechanical action in the process of cavitation leads to the widespread erosion of rock in nature. Although the mechanical action of flowing water body that accelerates the rock mass loss and fragmentation of rock (abrasion, erosion, and etching) and other phenomena have been much studied, its acceleration of mineral crystal dissolution is rarely reported. The physical mechanism of effect is not yet clear. The cavitation bubble produced in the cavitation process is at the micron level, and its related mechanical action leading to the accumulation of rock mineral dissolution is manifested in time and space in the process of the chemical element’s migration between water and rock minerals. Cavitation erosion may be one of the important driving forces for the migration of geochemical elements within the lithosphere and hydrosphere. In this paper, based on the crystal dissolution stepwave dynamic theory and the theoretical derivation and calculation of Gibbs free energy change of the mineral crystals plastic deformation which caused by the mechanical action of cavitation erosion, we give the possible mechanism of accelerating the transient dissolution of mineral crystals by cavitation erosion—the cavitation bubbles on the surface of the near crystal release the high speed micro-jet and shock wave perpendicular to the surface during the collapsing, in which the water hammer pressure produced by micro-jet at the solid–liquid interface causes instantaneous plastic deformation on the crystal surface under the condition that it is larger than the yield stress of the crystal. Under the influence of the thermal effect of the plastic deformation process and the change of Gibbs free energy (the dislocation elastic strain energy of plastic deformation on the crystal surface may be included), the local instantaneous dissolution rate of the mineral surface is accelerated. The continuous cavitation erosion eventually causes fracture and breaking of the mineral crystal, meanwhile, the Gibbs–Thomson effect may enhance the dissolution of mineral crystals more prominently. At the same time, the correctness of the mechanism is verified qualitatively by the acoustic cavitation experiment with the same erosion mechanism.

Riparian plant species composition alternates between species from standing and flowing water bodies – Results of field studies upstream and downstream of weirs along the German rivers Lahn and Fulda

Regulation measures like the installation of weirs led to distinct shifts in riparian plant communities and to a decline of typical riparian plant species occurring along the river shoreline, which is naturally poor in woody plants. These regulation measures include also run-of-river impoundments or weirs that cause distinct differences in hydrodynamic conditions in their direct proximity upstream and downstream. In the course of the year, the downstream reaches are exposed to significantly higher water level fluctuations than upstream. Thus, these reaches are assumed to provide also suitable habitat for riparian plant species of habitats being exposed to frequent disturbance by alternating water levels.We investigated the riparian vegetation in direct proximity upstream and downstream of nine weirs along the two regulated rivers Lahn and Fulda. Sampling was conducted in the transition zone from water to land directly above the actual water level during the summers 2016 and 2017. Differences in species composition were analyzed by means of NMS and indicator species analysis. Results of the indicator species analysis were used for further analyses regarding species’ functional traits and species’ habitat origin.A grouping of the relevés in accordance to the weir reach, dissimilarities in site conditions, significant indicator species for each weir reach and common indicator species upstream along both rivers point towards differences in species composition upstream and downstream. Due to rather constant water levels, upstream species composition consisted mainly of perennial species from reeds of still waters, swamp and alluvial forests and terrestrial habitats that were mainly competitors. By contrast, species from reeds of flowing waters, flooded meadows and grasslands and typical riparian plant communities (Bidention tripartitae, Chenopodion rubri) occurred more frequently downstream. Species downstream exhibited also less competitive power and short life cycles as a result of higher water level fluctuations.Upstream and downstream species composition clearly reflect the observed hydrodynamic conditions, restricting continuity to the area within two weirs. This distinctly differs from natural conditions, which leads to the establishment of novel riparian plant communities. As downstream reaches in direct proximity to weirs are related to higher water level fluctuations in the course of the year, these areas are of essential meaning as refuge for typical riparian species. Against this background, we recommend to decrease bank steepness downstream to increase the effect of water level fluctuations, which would lead to the establishment of suitable habitats for typical riparian plant species.

Regulatory Modeling of Pesticide Aquatic Exposures in California's Agricultural Receiving Waters.

For the aquatic exposure assessment of pesticides, the USEPA uses the Variable Volume Water Model (VVWM) to predict the estimated environmental concentrations (EECs) of a pesticide in a water body that receives runoff inputs from the Pesticide Root Zone Model (PRZM). The standard farm pond and additional generalized static and flowing water bodies used in endangered species assessment (aquatic bins) are used by USEPA to model the worst-case aquatic exposure for the nationwide exposure assessment. However, whether or not model results are relevant to state-specific conditions has not been validated. In this study, the USEPA water body scenarios are examined for their capability of providing a conservatively realistic estimate of pesticide aquatic exposures in California's agricultural settings. The sensitivity of modeled EECs to key water body parameters (dimensions, flow, and mass transfer) was explored with a one-at-a-time approach by using the standard farm pond as a baseline. The EECs generated from different USEPA water bodies for the worst-case loading were compared with the monitoring data observed in California's agriculturally influencing water bodies. Results showed that the farm pond EECs well captured the worst-case monitoring data, whereas the aquatic bins EECs, especially the flowing bins, tended to overestimate data. The conceptual model of the standard farm pond was also found to be relevant to the highly vulnerable water bodies in California's agricultural areas. The study confirms that VVWM with the standard farm pond scenario is appropriate for the screening-level regulatory exposure assessment in California's agricultural settings.

Seroprevalence of Rickettsia rickettsii and Rickettsia parkeri in dogs during a Brazilian Spotted Fever outbreak in the State of Rio de Janeiro

ABSTRACT The present paper is the first to perform this evaluation in dogs from the cities of Natividade, Porciuncula and Varre-Sai. The aim of this study is to search for Spotted Fever Group Rickettsia in canine sera using indirect immunofluorescence assay and to identify the probable causative agent of sera reactions in animals. Of the 253 sampled canines, 67.59% (171/253) were seroreactive for Rickettsia rickettsii and 11.07% (28/253) for Rickettsia parkeri, both in dilution 1:64. Titration of tested sera against R. rickettsii antigens reached 1:131.072 and, for R. parkeri, 1:4.096. We conclude that dogs are important sentinels for R. rickettsii infection, and can be infected regardless of sex, age, the habit of visiting woodlands or being in direct contact with equines and capybaras. Serological diagnosis has highlighted many dogs infected by R. rickettsii, and ambient conditions, such as the presence of flowing water bodies, was important for the occurrence of Brazilian Spotted Fever in the northwestern of Rio de Janeiro State.

Soil and Water Assessment Tool model predictions of annual maximum pesticide concentrations in high vulnerability watersheds.

Recent national regulatory assessments of potential pesticide exposure of threatened and endangered species in aquatic habitats have led to increased need for watershed-scale predictions of pesticide concentrations in flowing water bodies. This study was conducted to assess the ability of the uncalibrated Soil and Water Assessment Tool (SWAT) to predict annual maximum pesticide concentrations in the flowing water bodies of highly vulnerable small- to medium-sized watersheds. The SWAT was applied to 27 watersheds, largely within the midwest corn belt of the United States, ranging from 20 to 386 km2 , and evaluated using consistent input data sets and an uncalibrated parameterization approach. The watersheds were selected from the Atrazine Ecological Exposure Monitoring Program and the Heidelberg Tributary Loading Program, both of which contain high temporal resolution atrazine sampling data from watersheds with exceptionally high vulnerability to atrazine exposure. The model performance was assessed based upon predictions of annual maximum atrazine concentrations in 1-d and 60-d durations, predictions critical in pesticide-threatened and endangered species risk assessments when evaluating potential acute and chronic exposure to aquatic organisms. The simulation results showed that for nearly half of the watersheds simulated, the uncalibrated SWAT model was able to predict annual maximum pesticide concentrations within a narrow range of uncertainty resulting from atrazine application timing patterns. An uncalibrated model's predictive performance is essential for the assessment of pesticide exposure in flowing water bodies, the majority of which have insufficient monitoring data for direct calibration, even in data-rich countries. In situations in which SWAT over- or underpredicted the annual maximum concentrations, the magnitude of the over- or underprediction was commonly less than a factor of 2, indicating that the model and uncalibrated parameterization approach provide a capable method for predicting the aquatic exposure required to support pesticide regulatory decision making. Integr Environ Assess Manag 2018;14:358-368. © 2017 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Evaluation of Watershed-Scale Simulations of In-Stream Pesticide Concentrations from Off-Target Spray Drift.

The estimation of pesticide concentrations in surface water bodies is a critical component of the environmental risk assessment process required by regulatory agencies in North America, the European Union, and elsewhere. Pesticide transport to surface waters via deposition from off-field spray drift can be an important route of potential contamination. The spatial orientation of treated fields relative to receiving water bodies make prediction of off-target pesticide spray drift deposition and resulting aquatic estimated environmental concentrations (EECs) challenging at the watershed scale. The variability in wind conditions further complicates the simulation of the environmental processes leading to pesticide spray drift contributions to surface water. This study investigates the use of the Soil Water Assessment Tool (SWAT) for predicting concentrations of malathion (O,O-deimethyl thiophosphate of diethyl mercaptosuccinate) in a flowing water body when exposure is a result of off-target spray drift, and assesses the model's performance using a parameterization typical of a screening-level regulatory assessment. Six SWAT parameterizations, each including incrementally more site-specific data, are then evaluated to quantify changes in model performance. Results indicate that the SWAT model is an appropriate tool for simulating watershed scale concentrations of pesticides resulting from off-target spray drift deposition. The model predictions are significantly more accurate when the inputs and assumptions accurately reflect application practices and environmental conditions. Inclusion of detailed wind data had the most significant impact on improving model-predicted EECs in comparison to observed concentrations.

Enhanced CE-QUAL-W2 model to predict the fate and transport of volatile organic compounds in water body: Gheshlagh reservoir as case study

Intentional and/or accidental volatile organic compound (VOC) spill into water bodies may lead to severe contamination and health problems in water infrastructures. The importance and widespread use of petroleum products and the threats posed by these products on surface water resources in Iran necessitates the access to numerical hydrodynamic and water quality simulation models with appropriate capabilities. Simulation the fate and transport of VOC in both flowing and standing water bodies is a fairly complex problem. In this research, CE-QUAL-W2 model is modified to simulate the fate and transport of VOC [i.e., Methyl tert-butyl ether (MTBE), benzene] in standing and flowing water bodies. The performance of the modified CE-QUAL-W2 model is evaluated in a MTBE pollution spill at Khalife-Tarkhan river along the headwaters of Gheshlagh reservoir, Kordestan, Iran. The results show the modified CE-QUAL-W2 model’s capability to depict the spatial and temporal variation of MTBE in comparison with recorded data from MTBE spill event of Gheshlagh reservoir. Based on the simulation results of modified CE-QUAL-W2 model, reservoir cleanup time in different meteorological and hydrological scenarios is evaluated. The results show Gheshlagh reservoir cleanup time reduced in scenarios that included air temperature reduction, wind speed increasing, and high inflow condition.

The study of the variability of biomass from plants of the Elodea genus from a river in Germany over a period of two hydrological years for investigating their suitability for biogas production

BackgroundAquatic plants are an important component of aquatic ecosystems. They are valuable for the oxygen and carbon dioxide household and generate habitats especially for small fish and other small organisms. However, problems for the maintenance of water bodies can result from mass occurrences of these plants. Invasive neophytes - such as members of the Elodea genus - are particularly problematic in this regard. Aquatic plants need to be harvested regularly to ensure that water bodies remain usable and to safeguard flood protection for flowing water bodies. Energy can be produced from the harvested material by anaerobic digestion in biogas plants. Therefore, it is beneficial to know the best time for harvesting in this context.MethodsTo identify the best time for harvesting, samples of the Elodea stock in the river Parthe in Leipzig-Schönefeld were taken each week over the course of the two hydrological years 2015 and 2016. The composition of these samples was analyzed in the laboratory. In the second hydrological year, three samples from surface areas of 1 m2 were also harvested once each month in order to determine the biomass yield per unit area.ResultsThe best harvesting time for energy production from Elodea biomass in Germany is in the summer months (June to September). During this period, the specific yield of 0.5–0.7 kg VS/m2 is relatively high and the Elodea biomass contains the highest fractions of volatile solids (80.1 ± 2.3%), high contents of plant nutrients (N 35.9 ± 4.0 g/kg TS; P 6.1 ± 1.4 g/kg TS; and K 47.7 ± 8.0 g/kg TS), and low concentrations of heavy metals (Cr ≤8.9 mg/kg TS, Cd ≤0.9 mg/kg TS, Cu ≤120 mg/kg TS, Ni ≤30 mg/kg TS, Pb ≤8.6 mg/kg TS, and Zn ≤439 mg/kg TS).ConclusionsEnergy production from Elodea biomass is feasible. This biomass also provides the nutrients and trace elements necessary for the digestion in the anaerobic process.

Gibel carp Carassius auratus (Cyprinidae, Actinopterygii) in flowing water bodies of the Don River basin and the Lower Volga River basin

Data on the occurrence of Gibel carp in flowing water bodies of the Don River basin and the Lower Volga River basin are given. It is shown that gibel carp actively seeks for habitats with flowing water and can persist for a long time in streams with a current velocity from 1.0 to 1.3 m/s and overcome chutes with a current velocity of 2.6 m/s and streams with a depth of less than the body depth of the fish. Therefore, gibel carp is proposed to be considered as a lake–river fish. The outbreak of this species in streams is associated with its spawning period, when it moves in search of spawning grounds. It is assumed that these movements may contribute to its settling in rivers.

Mycobacterium ulcerans Persistence at a Village Water Source of Buruli Ulcer Patients

Buruli ulcer (BU), a neglected tropical disease of the skin and subcutaneous tissue, is caused by Mycobacterium ulcerans and is the third most common mycobacterial disease after tuberculosis and leprosy. While there is a strong association of the occurrence of the disease with stagnant or slow flowing water bodies, the exact mode of transmission of BU is not clear. M. ulcerans has emerged from the environmental fish pathogen M. marinum by acquisition of a virulence plasmid encoding the enzymes required for the production of the cytotoxic macrolide toxin mycolactone, which is a key factor in the pathogenesis of BU. Comparative genomic studies have further shown extensive pseudogene formation and downsizing of the M. ulcerans genome, indicative for an adaptation to a more stable ecological niche. This has raised the question whether this pathogen is still present in water-associated environmental reservoirs. Here we show persistence of M. ulcerans specific DNA sequences over a period of more than two years at a water contact location of BU patients in an endemic village of Cameroon. At defined positions in a shallow water hole used by the villagers for washing and bathing, detritus remained consistently positive for M. ulcerans DNA. The observed mean real-time PCR Ct difference of 1.45 between the insertion sequences IS2606 and IS2404 indicated that lineage 3 M. ulcerans, which cause human disease, persisted in this environment after successful treatment of all local patients. Underwater decaying organic matter may therefore represent a reservoir of M. ulcerans for direct infection of skin lesions or vector-associated transmission.

Scenario of Genotoxicity in Fishes and Its Impact on Fish Industry

Genotoxicity is a property possessed by some substances that makes them harmful to the genetic information contained in organisms. Heavy metal ions and polycyclic hydrocarbons are the most influencing genotoxicants for fishes. A large proportion of genotoxicants are disposed in free flowing water bodies and the funa particulary, fishes are highly affected. Accumulation of genotxicants not only effects the growth of fishes but also decrease the fecundity capacity. Liver and kidney are two important organs affected as enzymes like MT and ALT are playing pivotal role in detoxification of genotoxicants. Genotoxicants have pronounced influence on liver histology and biochemistry which resulted in structural damage to the vital organ. Screening and development of microbial strains and phytoplankton as bioaccumulating agents will help in decreasing pronounce of toxins leading to genetic material damage. The second level effect of genotoxins can be carcinogens, or cancer-causing agents, mutagens, or mutation-causing agents, or teratogens, birth defect- causing agents. The importance of the fisheries sector has been highlighted as a major food source. As an important activity allied to agriculture, it strengthens the productive base of agricultural economy and generates self- employment. Fish makes a vital contribution to the survival and health of a significant portion of the world's population. Fish is especially important in the developing world. In some of Asia's poorest countries (Bangladesh, Cambodia) people derive as much as 75% of their daily protein from fish. In West Africa fish accounts for 30% of animal protein intake, and this number would be larger if the poor could afford to buy more. Fish provides essential nourishment, especially quality proteins and fats (macronutrients), vitamins and minerals (micronutrients). Second, for those involved in fisheries, aquaculture and fish trade, fish is a source of income which can be used to purchase other additional food items. The fish industry has been threatened by natural and human activities. Aquatic ecosystems are continuously loaded with anthropogenic pollutants of which heavy metal ions, microbial toxins, and polycyclic aromatic hydrocarbons form an important group of concern. These pollutants are affecting stages of the aquatic food chain which may lead to the disturbance of the whole ecosystem. Fish

Analyzing near water surface penetration in laser bathymetry – A case study at the River Pielach

Abstract. Recent developments in sensor technology yielded a major progress in airborne laser bathymetry for capturing shallow water bodies. Modern topo-bathymetric small foot print laser scanners do no longer use the primary near infrared (NIR) signal (λ=1064 nm) but only emit and receive the frequency doubled green signal (λ= 532 nm). For calculating correct water depths accurate knowledge of the water surface (air-water-interface) is mandatory for obtaining accurate spot positions and water depths. Due to the ability of the green signal to penetrate water the first reflections do not exactly represent the water surface but, depending on environmental parameters like turbidity, a certain penetration into the water column can be observed. This raises the question if it is even feasible to determine correct water level heights from the green laser echoes only. In this article, therefore, the near water surface penetration properties of the green laser signal are analyzed based on a test flight of the River Pielach (Austria) carried out with Riegl's VQ-820-G (532 nm) and VQ-580 (1064 nm) scanners mounted on the same airborne platform. It is shown that within the study area the mean penetration into the water column is in the range of 10–25 cm compared to the NIR signal as reference. However, as the upper hull of the green water surface echoes coincides with the NIR signal with cm-precision, it is still possible to derive water surface models from the green laser echoes only via statistical analysis of aggregated neighboring echoes and robustly keep the underestimation of the water level below 6 cm. This especially holds for still and stationary flowing water bodies.

Osteology of the South Asian Genus Psilorhynchus McClelland, 1839 (Teleostei: Ostariophysi: Psilorhynchidae), with investigation of its phylogenetic relationships within the order Cypriniformes

Members of the genus Psilorhynchus are small benthic fishes, commonly referred to as torrent minnows, which inhabit the fast to swift flowing water bodies of the Indo-Burma region and the Western Ghats of Peninsular India. Despite being described scientifically in the mid 18th century, the morphology of Psilorhynchus remains poorly known and its phylogenetic placement within the order Cypriniformes is a matter of considerable debate. In this paper the osteology of Psilorhynchus sucatio is described and illustrated in detail. Notes and/or illustrations on the osteology of 12 other species of Psilorhynchus are also provided for the first time. A phylogenetic investigation of the position of Psilorhynchus within the order Cypriniformes is also conducted. Analysis of 127 morphological characters scored for 52 ingroup taxa (including 12 species of Psilorhynchus) and four outgroup taxa resulted in 14 equally parsimonious cladograms (287 steps long; consitency index, CI = 0.48; retention index, RI = 0.88). Psilorhynchus is recovered as the sister group to the family Cyprinidae, and is regarded as a member of the superfamily Cyprinoidea, which forms the sister group to the Cobitoidea (including all other cypriniform families). The sistergroup relationship between Psilorhynchus and Cyprinidae is supported by eight derived characters (five of which are homoplastic within the order Cypriniformes). The monophyly of Psilorhynchus is supported by 16 derived characters (eight of which are homoplastic within Cypriniformes). Three species groups of Psilorhynchus are proposed, the Psilorhynchus balitora group (including P. amplicephalus, P. balitora, P. breviminor, P. nepalensis, P. rahmani, P. pavimentatus, and P. brachyrhynchus), the Psilorhynchus gracilis group (including P. gracilis, P. melissa, P. robustus, and P. tenura), and the Psilorhynchus homaloptera group (including P. arunachalensis, P. homaloptera, P. microphthalmus, and P. pseudecheneis). The continued use of the family group name Psilorhynchidae is recommended. Comments on the interrelationships of the Cypriniformes are also provided. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011.

Effect of sex and age on temporal variation in the frequency and direction of platypus (Ornithorhynchus anatinus) captures in fyke nets

Fyke netting is currently the method mainly used to describe the demographic attributes of platypus (Ornithorhynchus anatinus) populations occupying relatively shallow, flowing water bodies. Based on fieldwork carried out in Victoria from 1995 to 2010, fyke netting surveys conducted in the month when the highest frequency of nightly captures was recorded (July) resulted in nearly three times as many adults and subadults entering nets as compared with those scheduled in the months when the fewest nightly captures were recorded (April and May). Significant sex-specific variation was apparent in relation to monthly capture frequencies: males were captured most often in August (the start of the breeding season), whereas females were captured most often in January (the peak period of lactation). The frequency of platypus captures also varied significantly when considered on a nocturnal time scale, with 63% of adult and subadult captures and 73% of juvenile captures being recorded in the first half of the night. Both juveniles (<11 months) and older animals also showed a significant tendency to travel upstream in the first half of the night. These potential sources of bias in datasets need to be considered when analysing and comparing the results of platypus fyke netting studies.

Osteology of the South Asian Genus Psilorhynchus McClelland, 1839 (Teleostei: Ostariophysi: Psilorhynchidae), with investigation of its phylogenetic relationships within the order Cypriniformes

Members of the genus Psilorhynchus are small benthic fishes, commonly referred to as torrent minnows, which inhabit the fast to swift flowing water bodies of the Indo-Burma region and the Western Ghats of Peninsular India. Despite being described scientifically in the mid 18th century, the morphology of Psilorhynchus remains poorly known and its phylogenetic placement within the order Cypriniformes is a matter of considerable debate. In this paper the osteology of Psilorhynchus sucatio is described and illustrated in detail. Notes and/or illustrations on the osteology of 12 other species of Psilorhynchus are also provided for the first time. A phylogenetic investigation of the position of Psilorhynchus within the order Cypriniformes is also conducted. Analysis of 127 morphological characters scored for 52 ingroup taxa (including 12 species of Psilorhynchus) and four outgroup taxa resulted in 14 equally parsimonious cladograms (287 steps long; consitency index, CI = 0.48; retention index, RI = 0.88). Psilorhynchus is recovered as the sister group to the family Cyprinidae, and is regarded as a member of the superfamily Cyprinoidea, which forms the sister group to the Cobitoidea (including all other cypriniform families). The sistergroup relationship between Psilorhynchus and Cyprinidae is supported by eight derived characters (five of which are homoplastic within the order Cypriniformes). The monophyly of Psilorhynchus is supported by 16 derived characters (eight of which are homoplastic within Cypriniformes). Three species groups of Psilorhynchus are proposed, the Psilorhynchus balitora group (including P. amplicephalus, P. balitora, P. breviminor, P. nepalensis, P. rahmani, P. pavimentatus, and P. brachyrhynchus), the Psilorhynchus gracilis group (including P. gracilis, P. melissa, P. robustus, and P. tenura), and the Psilorhynchus homaloptera group (including P. arunachalensis, P. homaloptera, P. microphthalmus, and P. pseudecheneis). The continued use of the family group name Psilorhynchidae is recommended. Comments on the interrelationships of the Cypriniformes are also provided.

Single Nucleotide Polymorphism Typing of Mycobacterium ulcerans Reveals Focal Transmission of Buruli Ulcer in a Highly Endemic Region of Ghana

Buruli ulcer (BU) is an emerging necrotizing disease of the skin and subcutaneous tissue caused by Mycobacterium ulcerans. While proximity to stagnant or slow flowing water bodies is a risk factor for acquiring BU, the epidemiology and mode of M. ulcerans transmission is poorly understood. Here we have used high-throughput DNA sequencing and comparisons of the genomes of seven M. ulcerans isolates that appeared monomorphic by existing typing methods. We identified a limited number of single nucleotide polymorphisms (SNPs) and developed a real-time PCR SNP typing method based on these differences. We then investigated clinical isolates of M. ulcerans on which we had detailed information concerning patient location and time of diagnosis. Within the Densu river basin of Ghana we observed dominance of one clonal complex and local clustering of some of the variants belonging to this complex. These results reveal focal transmission and demonstrate, that micro-epidemiological analyses by SNP typing has great potential to help us understand how M. ulcerans is transmitted.