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Most studies on black flies focus on the taxonomy and ecology of their aquatic stages. Despite posing a public health threat, the adults remain poorly studied in many countries, including Malaysia. The present study represents the first investigation of the distribution of wild-caught black flies from various ecological landscapes and climatic conditions in Malaysia. CO 2 -baited Malaise traps were set randomly at 41 sampling sites across Peninsular Malaysia from 2020 to 2023. In total, 532 black flies belonging to 14 species of four subgenera were captured. To ensure taxonomic rigor, specimens were identified to species morphologically and molecularly. The subgenus Gomphostilbia was the most abundant (71.43 %), followed by Simulium (14.28 %) and Davieselleum and Nevermannia each representing 7.14 % of the total captures. These species represented 14.74 % of the total species recorded from Malaysia. The most frequently collected species were Simulium roslihashimi (24.39 %), followed by S. aureohirtum, S. vanluni, and S. (Gomphostilbia) sp. 1 with 7.32 % each. The highest relative abundance was found for S. vanluni (86.09 %) and S. roslihashimi (7.14 %). Most species were found at elevation below 300 m (78.57 %); fewer were at elevation higher than 1,000 m (21.43 %). Two principal components accounted for 85.3 % of the total intersite variance. Simulium roslihashimi was found at almost every site, with a maximum relative humidity of 90 %. Simulium aureohirtum and S. vanluni were found at sites with relative humidity up to 73 %, but S. aureohirtum was found at higher temperatures (31 °C) compared with S. roslihashimi (28 °C) and S. vanluni (29 °C). The present study establishes the groundwork for further studies of wild adults in Malaysia and identifies the need to use more traps over the range of seasons and environmental conditions, particularly near breeding sites., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Nodding syndrome is one of several forms of onchocerciasis-associated epilepsy (OAE) seen among children in areas formerly hyperendemic for the transmission of Onchocerca volvulus. These forms of epilepsy are highly prevalent and clustered in certain villages located close to blackfly (Diptera: Simuliidae) breeding sites. OAE presents with a wide spectrum of seizures, including generalized tonic-clonic and head nodding seizures, impaired cognitive function, growth stunting and delayed puberty. In 2014, the present authors published a perspective paper in this journal which hypothesized that nodding syndrome may be caused by either a neurotropic virus transmitted by blackflies or an endosymbiont present within the O. volvulus parasite. Seven years later, this critical review presents progress in nodding syndrome research, and assesses whether it is still plausible that a neurotropic virus or endosymbiont could be the cause.

Mermithids are parasites of black flies that cause host mortality along with physical and behavioural changes in infected hosts. However, there is a lack of knowledge on the distribution of mermithids infecting black fly larvae and the factors that influence these distributions in Asia, including Malaysia. A total of 13,116 mid- to late-instar black fly larvae belonging to 42 species were collected from 138 streams across East and West Malaysia and screened for the presence of mermithid parasites. Overall, 121 mermithids were obtained from 107 (0.82%) larvae of nine (21.4%) black fly species. The average number of mermithids per black fly host was 1.10 ± 0.04 (SE), ranging from one to three mermithids per host. Mermithid infection was highest in Simulium trangense, with a frequency of occurrence of 6.5%, followed by S. cheongi (5.8%) and S. angulistylum complex (2.9%). Infection was lowest in S. brevipar and S. tahanense, with a frequency of occurrence of 0.7% each. Regression analysis indicated that mermithid infections in larval black flies were significantly associated with cooler and shallower streams with more canopy cover, dense riparian vegetation, high dissolved oxygen, and lower conductivity and complete pH. Forward logistic regression further indicated that infections in S. cheongi were associated with shaded, cooler, slightly acidic streams with higher conductivity and dissolved oxygen. These findings suggest that mermithid infections in larval black flies in Malaysia are not randomly distributed and are influenced by the breeding habitat of their hosts., (Copyright © 2022. Published by Elsevier B.V.)

Black flies (Diptera: Simuliidae) are among the most bothersome blood-sucking dipterans causing severe irritation and distress to poultry, wild birds, animals, and humans globally. These insects are vectors of viruses, bacteria, parasitic protozoans, and nematodes of humans and animals. Parasitic protozoa belonging to Haemosporida (Apicomplexa) are distributed worldwide and black flies are the principal vectors of avian haemosporidian parasites of the genus Leucocytozoon, a common parasite of birds. Based on the detection of parasite DNA in insects, 13 black fly species were reported to be potential vectors of Leucocytozoon in Europe. Information about which species of Simulium can play a role in the transmission of Leucocytozoon parasites is insufficient and needs to be developed. The aim of our study was to determine which black fly species are involved in the transmission of Leucocytozoon parasites in the Eastern Europe. The black fly females were collected in Lithuania using entomological net. They were morphologically identified, dissected to prepare salivary glands preparations, and then screened for the presence of Leucocytozoon parasites using microscopy and PCR-based methods. In all, we collected 437 black fly females belonging to eight species. The DNA of Leucocytozoon (genetic lineage lCOCO18) was detected in one of analysed females identified as Simulium maculatum. All salivary gland preparations were negative for the presence of Leucocytozoon sporozoites. Our results included S. maculatum as a potential vector of Leucocytozoon parasites. Increasing the knowledge on vector ecology, behaviour and improving collection methods may be the key to understand the evolution and diversity of these parasites., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The species status of two cytoforms of two species complexes in the Simulium (Simulium) tuberosum species-group, which are almost indistinguishable in the pupal stage, was morphologically and genetically evaluated. Cytoform 'L' of the S. (S.) tani Takaoka & Davies complex, previously recognized as S. (S.) suzukii Rubtsov in Taiwan, is described as a new species, S. (S.) jianshiense. It is morphologically distinguishable as adults from two members of the S. (S.) suzukii complex: cytoform 'C' from Hokkaido, selected to represent the type of S. (S.) suzukii sensu stricto, and cytoform 'D' from Okinawa Island and, based on our chromosomal analysis, also from Amami Island. This new species is genetically separated from both cytoforms of the S. (S.) suzukii complex with a genetic distance of 5.31-6.67%. Cytoform 'D' is distinguished from cytoform 'C' by the color of the male forecoxa and relative length of the female sensory vesicle to the third maxillary palpomere. Accordingly, the name S. (S.) ryukyuense Ogata, once regarded as a synonym of S. (S.) suzukii, is revalidated and applied to cytoform 'D'. The genetic distance between S. (S.) ryukyuense and S. (S.) suzukii sensu stricto is 1.24-1.60%., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The microtrichia of the labral fan primary rays, considered as the finest structure of the larval filter mechanism in Simuliidae, and the posterior proleg hooks, a structure used for substrate attachment, were describe using Scanning Electron Microscopy for the first time in 14 Neotropical species of black flies. Four patterns of primary rays microtrichia and two types of hooks barbs disposition were found. The present study provides new morphological information for Neotropical black fly species, compares it with previous information for worldwide species. Also, shows that the presence of posterior proleg hooks barbs is common among black fly species, that these barbs are not related with the larval habitat or with the primary ray microtrichia pattern, and that flow conditions may influence the last-instar larvae microtrichial patterns, at least in most of the Neotropical species studied here., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Onchocerciasis elimination is within reach in many countries but requires enhanced surveillance of the Simulium vectors of Onchocerca volvulus. Collection of sufficient numbers of adult Simulium to detect infective O. volvulus larvae is hindered by limited sampling tools for these flies. Here, we tested for the first time the Host Decoy Trap (HDT), an exposure free method previously developed for Anopheles vectors of malaria parasites, as a potential sampling tool for adult Simulium. In three replicates of a randomized Latin square experimental design, the HDT was compared to Human Landing Catches (HLC) and the Esperanza Window Trap (EWT). A total of 8,531 adult S. damnosum sensu lato blackflies (S. squamosum group) were found in catches from the three different trapping methods. The HDT (mean catch 533 ± 111) caught significantly more S. squamosum than the EWT (mean catch 9.1 ± 2.2), a nearly 60-fold difference. There was no significant difference between the HLC (mean catch 385.6 ± 80.9) and the HDT. Larvae indistinguishable from those of O. volvulus were dissected from 2.86% of HDT samples (n = 70) and 0.35% of HLC samples (n = 285); a single infective third-stage larvae (L3) was  found during dissection of a sample from the HDT. Owing to its very high capture rate, which was comparable to the HLC and significantly greater than EWT, alongside the presence of infected flies in its catch, the HDT represents a potentially valuable new tool for blackfly collection in elimination settings, where thousands of flies are needed for parasite screening., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Three new species of black flies from Thailand, Simulium wangkwaiense, S. tadtonense and S. maeklongkeense, are described based on their adults, pupal exuviae and cocoons. All three new species are assigned to the Simulium (Simulium) striatum species-group, bringing its total number in Thailand to seven. Simulium wangkwaiense sp. nov. is the species formerly called S. quinquestriatum in Thailand. Certain male and pupal morphological characteristics are shown to separate all seven Thai species of this species-group. All of the three new species have been analyzed genetically for their phylogenetic relationships, with three known related species (except for S. thailandicum), by using the fast-evolving nuclear big zinc finger (BZF) gene., Competing Interests: Declaration of Competing Interest All authors declare that we have no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Identification of the host blood meal of hematophagous insects can provide significant information regarding host preferences and the possibility of the transmission of disease agents. Currently, this knowledge is limited for black flies in the Oriental region. In this study, we used cytochrome b gene sequences for identification of blood meal sources of two black fly taxa, the Simulium asakoae complex and S. chumpornense Takaoka & Kuvangkadilok in Thailand. A total of 4,260 wild adult females were visually screened revealing 24 blood-engorged females from which cytochrome b was successfully amplified in 19 individuals. Comparisons in GenBank database revealed that all are closest to chicken (Gallus gallus) with sequence similarity of >98%. Therefore, these black fly species are feeding on chickens. We also molecularly investigated the hemosporidian blood protozoa genus Leucocytozoon in black flies and found 13 of 19 blood-engorged females positive for this protozoon. Sequence analysis revealed that this Leucocytozoon DNA could be assigned into two previously recognized groups, one with a Leucocytozoon reported from domestic chickens and black flies in Thailand, and another close to the L. schoutedeni. Our results indicate a high possibility that the S. asakoae complex and S. chumpornense are natural vectors of Leucocytozoon., Competing Interests: Declaration of Competing Interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The ecology of black flies in Thailand was investigated, based on 19,451 larvae and pupae collected from 65 stream sites in 10 northern provinces during the rainy, cool, and hot seasons, and 1,906 larvae and pupae collected from 18 sites in 9 southern provinces during the cool season. Twenty-seven black fly species were identified from northern Thailand, of which 26 were found in the cool season, when richness was greatest. Significant regressions between species richness and elevation fit a unimodal model in the rainy season but a linear model in the cool and hot seasons. Twenty-two species occurred in all seasons. Species in the subgenera Gomphostilbia and Nevermannia were most common in the hot season, whereas species in the subgenus Simulium were predominant in the cool season. Some species (e.g., S. nakhonense) were geographically widespread, whereas others (e.g., S. chaliowae and S. weji) were restricted to particular localities. Eighteen species and species complexes were found in southern Thailand. The S. tani complex was the most widely distributed taxon, occurring at 66.7% of the sites in the South. Ecological analyses revealed that water temperature, elevation, conductivity, dissolved oxygen, and stream size were among the significant factors associated with the distributions of black flies in both regions of Thailand-the same factors associated with simuliid distributions in other areas of the world., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing financial interests or personal relationships that influenced the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Blackflies (Diptera: Simuliidae) are ecologically and medically important insects but they have been understudied in Malaysia. Accordingly, a study on the temporal variation in diversity and community structure of preimaginal blackflies was conducted for the first time in Malaysia. A total of 865 preimaginal blackflies were collected in 120 samplings from five streams across three monsoon seasons from February 2018 until January 2019. Ten species were recorded and most frequently collected species were Simulium cheongi, Simulium vanluni and Simulium jeffreyi. Relatively common species were Simulium roslihashimi, Simulium tani complex and Simulium trangense. No significant changes of rainfall was observed between three monsoon seasons as well as the seasons with species and physiochemical parameters except acidity (pH) (P < 0.01). Species relative abundance was varied between seasons, as high value of Shannon index (H) was found in northeast monsoon and lowest in the southwest monsoon. Principal Component Analysis (PCA) of all stream variables revealed two PCs that accounted for 61.4% of the total variance of physicochemical characteristics. Regression analysis revealed that species richness was positively and significantly associated with wider, deeper, faster, low conductivity and larger streambed particle with less canopy cover. Forward logistic regression analysis on three frequently collected species (>20%) indicated that S. vanluni and S. jeffreyi were commonly associated with wider, deeper and fast-flowing streams with low conductivity and larger streambed particle. In contrast, S. cheongi was associated with smaller, slower and small streambed particle. This first extensive bimonthly study has uncovered the species community structure as well as the changes of stream physicochemical parameters over time although they were not greatly and significantly influenced by the monsoon seasons. Species distribution, richness and abundance, however, were highly determined by the stream width, depth and velocity, therefore, were vital in shaping diversity and community structure of preimaginal blackflies., Competing Interests: Declaration of Competing Interest We declare that this is our original work. It has not been published elsewhere. We have no conflict of interest regarding the content reported in this manuscript. All authors have contributed to the study. The authors have read and approved this revised manuscript., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Trypanosomes are parasitic flagellate protozoans that are important disease causing agents in humans and animals including economically significant livestock. Many blood-sucking insects are known to be vectors of trypanosomes but there is no data for the haematophagous black fly species in Asia. In this study, a molecular approach based on the small subunit ribosomal RNA (SSU rRNA) gene was used to detect trypanosomes in black flies from Thailand. A total of 470 wild-caught adult black flies representing nine morphological species were examined. Ten (2%) specimens of two ornithophilic black fly species, Simulium asakoae complex (n = 4) and S. chumpornense (n = 6), were positive for trypanosomes. The SSU rRNA sequences revealed that all trypanosome DNA found in black flies from Thailand is closely related to Trypanosoma avium with >99% sequence similarity. This is also supported by a phylogenetic analysis in which all trypanosomes from Thai black flies were resolved in the clade of T. avium. This is the first report for trypanosomes in Asian black flies and it is suspected that these insects are potential vectors of avian Trypanosoma., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Black flies (Simuliidae) are important biting insects and vectors of diseases agents of humans and livestock. Thus, understanding the taxonomy and biodiversity of these insects is crucial for control and management of these diseases. In this study, we used mitochondrial cytochrome c oxidase I sequences to examine genetic diversity of three human-biting and possible vector black fly taxa; the Simulium asakoae species-complex, S. chamlongi and S. nigrogilvum. High levels of genetic diversity (>3.5% intraspecific genetic divergence) were found in all three taxa. Phylogenetic analyses indicated that the S. asakoae complex can be divided into seven groups with the largest group consisting of specimens from Thailand, Malaysia and Myanmar. This group most likely represents true S. asakoae. The remaining haplotypes formed groups with conspecific haplotypes or with other closely related species. Among these groups, one including S. monglaense and another including S. myanmarense suggest that certain specimens identified as S. asakoae most likely belong to those species. Therefore, they constitute new locality records for Thailand and also represent new records of anthropophily. Members of S. chamlongi are not monophyletic as its clade also included S. hackeri. A median joining network revealed strong geographic associations of the haplotypes of S. nigrogilvum suggesting limitation of gene flow. Because this species occurs mainly in high elevation habitats, low land areas could present a barrier to gene flow., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Simulium (Gomphostilbia) aziruni Takaoka, Hashim & Chen was described initially based only on a pupa and a mature larva collected from Peninsular Malaysia. Herein, we describe the morphological characters of the female of S. aziruni for the first time. It resembles those of the other members of the Simulium gombakense species-group by the genital fork with a distinct projection directed medioposteriorly from each arm and claw with a large basal tooth. Cytochrome c oxidase I (COI) barcoding analysis indicates that S. aziruni is the sister species of S. maleewongae, but both are distantly separated by a genetic distance of 4.9%., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Information regarding vector-parasite association is necessary for fully understanding the epidemiology of vector borne diseases yet, this information is lacking in the case of Leucocytozoonosis in the Oriental region, despite a high incidence of the disease. In this study, we used a molecular approach based on mitochondrial cytochrome b (cyt b) sequence to detect the parasite, Leucocytozoon, in potential black fly (Simuliidae) vectors in Thailand. A total of 404 wild caught black flies representing six morphological species of two subgenera were examined.- Gomphostilbia (Simulium asakoae complex, S. chumpornense) and Simulium (S. chamlongi, S. nodosum, S. nigrogilvum). Forty-four black fly specimens from two species of the Gomphostilbia were positive for Leucocytozoon. Most (35) of these were found in a village where high numbers of domestic chicken were kept, consistent with the possibility that chickens are a host of Leucocytozoon species found in black flies. Sixteen haplotypes were identified among 44 cyt b sequences. Comparisons of the sequences with previous reports revealed that the 11 haplotypes obtained in this study were identical or very similar to unknown Leucocytozoon found in infected domestic chickens. Four haplotypes are genetically similar to L. schoutedeni and one haplotype is genetically very different from existing cyt b sequences in public database. Our results indicate that two black fly species of the subgenus Gomphostilbia in Thailand are possible vectors of Leucocytozoon transmitted among poultry and wild birds in the country., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Simulium (Simulium) hackeri Edwards, 1928 of the Simulium variegatum species-group from Malaysia was described initially based on the female specimen from Cameron Highlands, Pahang. In the present study, the pupa and larva of this species are described for the first time. Their morphological characters resemble those of the Simulium variegatum species-group by having six gill filaments per side, abdomen with dorsal spine-combs at least on segments 7 and 8, cocoon with wall-pocket shaped and with or without an anterodorsal projection. Postgenal cleft of the larva medium-sized, rarely small, ventral papillae small or absent. The DNA barcode of this species is also reported herein., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Simulium (Simulium) rasuli sp. nov. is described from two females collected by a Malaise trap in Genting Highlands, Peninsular Malaysia. This new species is placed in the Simulium christophersi species-group of the subgenus Simulium. The female of this new specie is characterized by the scutum with three longitudinal vittae, dark legs, claw with a small subbasal tooth, and ovipositor valve triangular with its inner margin nearly straight. This new species is distinguished in the female from all the six named species of the species-group by the entirely brownish-black femora and tibiae., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Black flies (Diptera: Simuliidae) are important insect vectors and pests of humans and animals. Accurate identification, therefore, is important for control and management. In this study, we used mitochondrial cytochrome oxidase I (COI) barcoding sequences to test the efficiency of species identification for the human-biting black flies in Thailand. We used human-biting specimens because they enabled us to link information with previous studies involving the immature stages. Three black fly taxa, Simulium nodosum, S. nigrogilvum and S. doipuiense complex, were collected. The S. doipuiense complex was confirmed for the first time as having human-biting habits. The COI sequences revealed considerable genetic diversity in all three species. Comparisons to a COI sequence library of black flies in Thailand and in a public database indicated a high efficiency for specimen identification for S. nodosum and S. nigrogilvum, but this method was not successful for the S. doipuiense complex. Phylogenetic analyses revealed two divergent lineages in the S. doipuiense complex. Human-biting specimens formed a separate clade from other members of this complex. The results are consistent with the Barcoding Index Number System (BINs) analysis that found six BINs in the S. doipuiense complex. Further taxonomic work is needed to clarify the species status of these human-biting specimens., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Onchocerciasis is a neglected parasitic disease affecting the poorest underserved people in Yemen. A national control programme with goals to eliminate onchocerciasis has yet to be launched due to the current upheaval and social unrest in the country. The disease, locally termed as sowda, is unique in its clinicopathologic pattern, being of the localized, non-blinding, hyperreactive onchocercal skin disease. Although early reports identified endemic foci along seasonal watercourses, there is a need to redefine its epidemiologic patterns as well as health and socioeconomic impacts. Laboratory diagnosis of sowda among Yemeni patients is difficult due to the low load of microfilariae in skin snips and the presence of asymptomatic itching-free microfilaria carriers. Adoption of ivermectin use at three-month intervals as a control strategy has not been evaluated because the drug is mostly used in clinics and distributed to only a few affected communities. This paper addresses key aspects of onchocerciasis in Yemen and highlights the need for screening at-risk populations using highly sensitive techniques and mapping the distributions of the parasite in human and vector populations of blackflies. The new research should be integrated with the launch of a national onchocerciasis control programme to achieve onchocerciasis elimination., (Copyright © 2016 Elsevier B.V. All rights reserved.)

To investigate the breeding habitat preference of black flies, a comprehensive black fly survey was conducted for the first time in Peninsular Malaysia. Preimaginal black flies (pupae and larvae) were collected manually from 180 stream points encompassing northern, southern, central and east coast of the Peninsular Malaysia. A total of 47 black fly species were recorded in this study. The predominant species were Simulium trangense (36.7%) and Simulium angulistylum (33.3%). Relatively common species were Simulium cheongi (29.4%), Simulium tani (25.6%), Simulium nobile (16.2%), Simulium sheilae (14.5%) and Simulium bishopi (10.6%). Principal Component Analysis (PCA) of all stream variables revealed four PCs that accounted for 69.3% of the total intersite variance. Regression analysis revealed that high species richness is associated with larger, deeper, faster and higher discharge streams with larger streambed particles, more riparian vegetation and low pH (F=22.7, d.f.=1, 173; P<0.001). Relationship between species occurrence of seven common species (present in >10% of the sampling sites) was assessed. Forward logistic regression analysis indicated that four species were significantly related to the stream variables. S. nobile and S. tani prefer large, fast flowing streams with higher pH, large streambed particles and riparian trees. S. bishopi was commonly found at high elevation with cooler stream, low conductivity, higher conductivity and more riparian trees. In contrast, S. sheilae was negatively correlated with PC-2, thus, this species commonly found at low elevation, warmer stream with low conductivity and less riparian trees. The results of this study are consistent with previous studies from other geographic regions, which indicated that both physical and chemical stream conditions are the key factors for black fly ecology., (Copyright © 2015 Elsevier B.V. All rights reserved.)

This is the first study on the seasonal biodiversity of black flies and evaluation of ecological factors influencing their distribution at Doi Pha Hom Pok National Park, northern Thailand. Larvae were collected from six fixed-stream sites in relation to altitude gradients from May 2011 to April 2013. The water temperature, water pH, conductivity, total dissolved solids (TDS), salt, water velocity, stream width and depth, streambed particle sizes, riparian vegetation, and canopy cover were recorded from each site. Monthly collections from the six sites yielded 5475 last-instar larvae, belonging to 29 black fly species. The most frequently found species from all sites were Simulium asakoae (100%) followed by Simulium yuphae (83.3%), and Simulium chiangdaoense, Simulium gombakense, Simulium phahompokense, Simulium fruticosum, Simulium maeaiense and Simulium fenestratum (66.6%). Of the 5475 last-instar larvae, S. maeaiense (19.3%), S. chiangdaoense (15.8%) and S. asakoae (14.8%), were the three most abundant species. The Shannon diversity index (H) at the six sites with different altitudes of 2100m, 2000m, 1500m, 1400m, 700m, and 500m above mean sea level, were 2.042, 1.832, 2.158, 2.123, 1.821 and 1.822, respectively. The Shannon index and number of taxa in the cold season were higher than those in the rainy and hot seasons. Principal component analysis (PCA) indicated that at least three principal components have eigen values >1.0 and accounted for 93.5% of the total variability of ecological factors among sampling sites. The Canonical correspondence analyses (CCA) showed that most species had a trend towards altitude, canopy cover, riparian vegetation and water velocity., (Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.)