Coleópteros acuáticos (C. H. Zimapán), Hidalgo, México. II. Coleoptera: Polyphaga y Myxophaga.

A faunistic study on the aquatic Coleoptera suborders Polyphaga and Myxophaga was conducted in Zimapan’s influence area. Samples were taken monthly, from August 1995 to July 1996 in five water bodies. The structure of the assemblage of each water body was described and compared each other in terms of richness and composition, Shannon’s diversity index, Pielou’s evenness index, rareness and density. Distributional and seasonal data for each species are provided. A list of species and an illustrated key are also included. A faunal comparison to other areas of Mexico was intended. A total of 8,787 imagoes belonging to 42 species of 27 genera included in 10 families were collected. The highest richness and diversity was observed at San Francisco River, while a similar diversity and dominance values were obtained from Tula River and El Saucillo stream. The highest annual average density was recorded from El Saucillo stream, whereas a similar annual density was observed from both San Juan and Tula rivers. The highest number of rare species was registered at El Saucillo stream. Six families are recorded for the first time for Hidalgo state (Dryopidae, Limnichidae, Lutrochidae, Psephenidae, Heteroceridae y Microsporidae), as well as 19 genera (Helichus, Postelichus, Limnichoderus, Limnichites, Lutrochus, Psephenus, Dampfius , Microsporus, Laccobius, Berosus, Hemiosus, Hydrophilus, Chaetarthria, Anacaena, Helochares, Phaenonotum, Limnebius, Microcylloepus, Neoelmis) and 31 species (Helichus suturalis, Postelichus musgravei, Postelichus thoracicus, Limnichoderus lutrochinus, Limnichites nebulosus, Psephenus palpalis, P. oresbius, Lutrochus arizonichus, Dampfius mexicanus, Microcylloepus inaequalis, Neoelmis sp., Laccobius mexicanus, Berosus mexicanus, B. moerens, B. punctatissimus, Hemiosus exilis, Tropisternus lateralis nimbatus, Hydrophilus insularis, H. triangularis, Chaetarthria sp., Anacaena sp., Paracymus armatus, P. regularis, Enochrus carinatus fucatus, E. cristatus, E. pygmaeus pygmaeus, E. p. pectoralis, E. mexicanus, Helochares normatus, Limnebius sinuatus, Ochthebius angularidus).Se realizó un estudio faunístico de la comunidad de coleópteros acuáticos de los subórdenes Polyphaga y Myxophaga en el área de influencia de la Central Hidroeléctrica de Zimapán, Hidalgo, mediante muestreos mensuales en un ciclo anual (agosto-95 a julio-96) en cinco cuerpos de agua. De manera general, se describen y comparan entre sí la estructura de cada ensamblaje en términos de riqueza, composición, diversidad de Shannon, equitatividad de Pielou, rareza y densidad, adicionando datos de distribución de las especies dentro de la zona de estudio. Se hace una comparación faunística con otras áreas del país, y se proporciona una lista anotada y una clave ilustrada para las especies. Se recolectó un total de 8,787 adultos pertenecientes a 42 especies de 27 géneros y 10 familias. El Río San Francisco (RSF) presentó la mayor riqueza y diversidad, mientras que el Río Tula (RT) y arroyo El Saucillo (AES) registraron valores de diversidad y dominancia similares. AES exhibió la mayor densidad media anual, mientras que el Río San Juan (RSJ) y Río Tula (RT) presentaron una densidad media similar; AES obtuvo el mayor valor en rareza de especies. Se registran por primera vez para el estado de Hidalgo seis familias (Dryopidae, Limnichidae, Lutrochidae, Psephenidae, Heteroceridae y Microsporidae), 19 géneros (Helichus, Postelichus, Limnichoderus, Limnichites, Lutrochus, Psephenus, Dampfius, Microsporus, Laccobius, Berosus, Hemiosus, Hydrophilus, Chaetarthria, Anacaena, Helochares, Phaenonotum, Limnebius, Microcylloepus y Neoelmis) y 31 especies (Helichus suturalis, Postelichus musgravei, P. thoracicus, Limnichoderus lutrochinus, Limnichites nebulosus, Psephenus palpalis, P. oresbius, Lutrochus arizonichus, Dampfius mexicanus, Microcylloepus inaequalis, Neoelmis sp., Laccobius mexicanus, Berosus mexicanus, B. moerens, B. punctatissimus, Hemiosus exilis, Tropisternus lateralis nimbatus, Hydrophilus insularis, H. triangularis, Chaetarthria sp., Anacaena sp., Paracymus armatus, P. regularis, Enochrus carinatus fucatus, E. cristatus, E. pygmaeus pygmaeus, E. p. pectoralis, E. mexicanus, Helochares normatus, Limnebius sinuatus, Ochthebius angularidus)