Explore the vast range of titles available.

The riffle beetle genus Sinonychus Jäch & Boukal, 1995 (Elminae, Macronychini) includes only three species from East Asia. In this paper, two new species, S. lipinae sp. nov. and S. luodianensis sp. nov. , are described from Guizhou Province, China. Illustrations of the new species and a key to all five Sinonychus species are also provided.

Three new riffle beetles of the genus Zaitzevia Champion, 1923 are described from China, namely Zaitzevia sichuanensis sp. nov. and Zaitzevia fengtongzhaiensis sp. nov. from Sichuan Province, and Zaitzevia yingzuijieensis sp. nov. from Hunan Province. Habitus and diagnostic features of the new species are illustrated. A checklist of all known Chinese Zaitzevia species is given, and a key and distributional map of Zaitzevia species from the Chinese mainland are provided.

The genus Grouvellinus Champion, 1923 comprises 60 described species distributed across the Oriental and Palearctic regions. Species diversity is very high in mainland China, with 28 recorded species. Here, the results of the aquatic beetle survey in Guizhou Province are presented; they began in 2021, when we collected more than 5000 specimens of riffle beetle. All specimens come from small ravine streams where inhabited submerged stones. Using morphological characters of adults such as body form and size, coloration, elytral, pronotal and ventral surface structures, and forms of male and female genitalia, five new species were discovered and are described: Grouvellinus loong sp. nov. , G. buyi sp. nov. , G. wangmoensis sp. nov. , G. lihaitaoi sp. nov. , G. muyinlini sp. nov. The species descriptions contain illustrations of diagnostic characters and measurements of metric characters such as body length, pronotal length, pronotal width, elytral length and width, and head length and width. The females are, on average, larger and have only slight differences in external morphology compared to the males. The comparative diagnoses discuss characters of the new and already known species. The results show that the existing species diversity requires more detailed research focusing on larger areas of South China in the future.

The three genera and four species of Larainae (Elmidae) previously described from Australia are reviewed, and one new genus and seven new species are described: Australara glaisteri gen. et sp. nov. , Ovolara lawrencei sp. nov. , Ovolara monteithi sp. nov. , Stetholus carinatus sp. nov. , Stetholus longipennis sp. nov. , Stetholus metatibialis sp. nov. , and Stetholus woronora sp. nov. A lectotype is designated for Hydora laticeps (Carter & Zeck), and the first new collection records of the species are reported since its description in 1932. The occurrence in Australia of Potamophilinus papuanus Satô, described from Papua New Guinea, is reported. A key to the species, photographic images of the external morphology and male genitalia, distribution maps, and habitat and behavioral information, when known, are provided for all twelve species of Australian Larainae.

Further results are presented of the first field course at Maliau Basin, Malaysian Borneo organized by Taxon Expeditions, an organization which enables citizen scientists to be directly involved in taxonomic discoveries. Three new species of the aquatic beetle genus Grouvellinus Champion, 1923, namely G.leonardodicaprioi sp. n. , G. andrekuipersi sp. n. , and G.quest sp. n. were collected jointly by the citizen scientists and taxonomists during the fieldwork in Maliau Basin. Material was mainly sampled from sandstone bottom rocks of blackwater streams at altitudes between 900 m and 1,000 m using fine-meshed hand-nets. The genus is widely distributed in the Oriental and Palearctic regions, but these are the first records from the island of Borneo.

Whereas the response of lotic benthic macroinvertebrates to different environmental stressors is a widespread practice nowadays in assessing the water and habitat quality, the use of hyporheic zone invertebrates is still in its infancy. In this study, classification and regression trees analysis were employed in order to assess the ecological requirements and the potential as bioindicators for the hyporheic zone invertebrates inhabiting four lowland chalk rivers (south England) with contrasting eutrophication levels (based on surface nitrate concentrations) and magnitude of land use (based on percentage of fine sediments load and median interstitial space). Samples of fauna, water and sediment were sampled twice, during low (summer) and high (winter) groundwater level, at depths of 20 and 35 cm. Certain groups of invertebrates (Glossosomatidae and Psychomyiidae caddisflies, and riffle beetles) proved to be good indicators of rural catchments, moderately eutrophic and with high fine sediment load. A diverse community dominated by microcrustaceans (copepods and ostracods) were found as good indicators of highly eutrophic urban streams, with moderate-high fine sediment load. However, the use of other taxonomic groups (e.g. chironomids, oligochaetes, nematodes, water mites and the amphipod Gammarus pulex), very widespread in the hyporheic zone of all sampled rivers, is of limited use because of their high tolerance to the analysed stressors. We recommend the use of certain taxonomic groups (comprising both meiofauna and macroinvertebrates) dwelling in the chalk hyporheic zone as indicators of eutrophication and colmation and, along with routine benthic sampling protocols, for a more comprehensive water and habitat quality assessment of chalk rivers.

Two new species of the genus Dryopomorphus Hinton, 1936 are described from China: Dryopomorphusheineri sp. n. and D.ruiliensis sp. n. Habitus photographs and detailed line drawings of the male genitalia are provided.

In this study, patterns of body size of Phanocerus clavicornis Sharp, 1882 (Coleoptera: Elmidae: Larainae) were investigated along a gradient of change in speed of flow conditions in streams of low order in the Atlantic Rainforest in southeastern Brazil. Specifically, the hypothesis that the distribution of P. clavicornis larvae vary in size in response to variations in the speed of flow in streams was tested. A Surber sampler was used to collect larvae from the streambed during two sampling periods, defined by the rain regime: August in the dry season and February in the rainy season. Possible differences in mean measured body size were tested by analysis of variance (ANOVA). The ANOVA result indicated for all measurements on the larvae collected in first-order streams (head width, prothoracic width and total body length), there were significant differences indicating a morphometric variation due to changing hydraulic conditions, the smallest larvae being associated with the period of greater rainfall. However, the larger streams (3rd order), where the rain events had less impact on the larval size, varied widely. The results of this study suggest that the interstitial space is important for the protection of the larvae from water flow, and that populations of P. clavicornis have high plasticity, a key feature for the occupation of unstable environments for this species. These results are important for an understanding of the life history and behavioural characteristics of the species, which allow them to persist in streams along a gradient of flow disturbance. Neste estudo, padrões de tamanho do corpo de Phanocerus clavicornis Sharp, 1882 (Coleoptera: Elmidae: Larainae) foram investigados ao longo de um gradiente de variação de velocidade da corrente em córregos de baixa ordem da Mata Atlântica. Especificamente, buscou-se testar a hipótese de que a distribuição de larvas de P. clavicornis com diferentes tamanhos corpóreos respondem às variações na velocidade da corrente em córregos. As coletas das larvas foram realizadas com um amostrador de Surber durante dois períodos amostrais, definidos pelo regime de chuvas: agosto - estação seca e fevereiro - estação chuvosa. Possíveis diferenças nas medidas de tamanho do corpo foram testadas através de uma análise de variância (ANOVA). Os resultados daANOVAindicaram para todas as medidas das larvas coletadas nos córregos de primeira ordem (largura da cabeça, largura do protórax e comprimento total do corpo) encontramos diferenças significativas, indicando uma variação morfométrica com as mudanças das condições hidráulicas, onde as larvas menores foram associadas aos períodos de maior precipitação. No entanto, em córregos maiores (3a ordem), os eventos de chuva tiveram menor impacto no tamanho dos indivíduos, com a ocorrência de larvas com diferentes tamanhos. Os resultados deste estudo sugerem que os espaços intersticiais são importantes para a proteção das larvas contra a velocidade da corrente e que as populações de P. clavicornis possuem alta plasticidade, sendo uma característica fundamental para a ocupação desta espécie em ambientes instáveis. Esses resultados são importantes para a compreensão da história de vida e características comportamentais da espécie, que permitem persistir em córregos ao longo de gradiente de perturbação do fluxo.

Inventories provide information on the state of biodiversity at a site or for a geographic region. Species inventories are the basis for systematic study and critical to ecology, biogeography and identification of biological indicators and key species. They also provide key information for assessments of environmental change, for natural resource conservation or recovery of degraded ecosystems. Thus, inventories play a key role in planning strategies for conservation and sustainable use. This study aimed to inventory the fauna of water beetles, larvae and adults, in two mountainous regions in the state of São Paulo, in Serra da Mantiqueira (Parque Estadual de Campos do Jordão and Pindamonhangaba region) and in Serra do Mar (Santa Virgínia and Picinguaba Divisions) as well as to generate information about the habitats used by the different genera recorded. Specimens were collected in lotic and lentic systems, between the years 2005 to 2010. In total 14,492 specimens were collected and 16 families and 50 genera of Coleoptera were identified. This study in mountainous regions showed a significant portion of the faunal composition of South America and the state of São Paulo. The composition of the fauna, in terms of richness and abundance by family, indicated the predominance of Elmidae, followed by Hydrophilidae and Dytiscidae. Despite the diversity found, the results of estimated richness indicated the need for additional sampling effort for both regions, since the curves of estimated richness did not reach an asymptote, suggesting that new species can be found in future surveys. Os inventários fornecem informações do estado da biodiversidade de um local ou uma região geográfica. O inventário de espécies é a base para o estudo de sistemática e é essencial para a ecologia, a biogeografia e a identificação de bioindicadores e espécies-chave. Eles também fornecem informações fundamentais para avaliações de alterações ambientais, para a conservação de recursos naturais ou a recuperação de ecossistemas degradados. Assim, os inventários cumprem um importante papel no planejamento de estratégias de conservação e uso sustentável. Este trabalho teve como objetivo inventariar a fauna de Coleoptera aquáticos, larvas e adultos, em duas regiões montanhosas no Estado de São Paulo, na Serra da Mantiqueira (Parque Estadual de Campos do Jordão e região de Pindamonhangaba) e na Serra do Mar (Núcleos Santa Virgínia e Picinguaba), bem como gerar informações sobre os hábitats utilizados pelos diversos gêneros registrados. Os espécimes foram coletados, em sistemas lóticos e lênticos, entre os anos de 2005 e 2010. No total, foram coletados 14.492 exemplares e identificados 16 famílias e 50 gêneros de Coleoptera. Este estudo em regiões montanhosas apresentou uma porção significativa da composição faunística da América do Sul e do Estado de São Paulo. A composição da fauna em termos de riqueza e abundância por família indicou a predominância de Elmidae, seguida por Hydrophilidae e Dytiscidae. Apesar da alta riqueza encontrada, os resultados indicaram a necessidade de maior esforço amostral para ambas as regiões, uma vez que as curvas de estimativa de riqueza não atingiram a assíntota, sugerindo que novas espécies podem ser encontradas em levantamentos futuros.