In this paper we apply biological indices of environmental quality and conservation, based on biological monitoring conducted between 2003 and 2009 in five localities of the Bajo Urubamba River. Communities of plankton, benthos and fishes were studied. The diversity of plankton was 170 species, mainly based on Chlorophyta and Bacillariophyta. The benthos included 112 species, mainly larvae and adults of Arthropoda (Insecta). 176 fish species were recorded, represented by 26 families and six orders. The quality of the study area ranged from normal to very good, according to the index %ETP. The conservation index of aquatic environments (IBI) gave the higher values for Miari and Sepahua. The high diversity of the communities studied could be related to the heterogeneity of habitats and greater resources than are observed in the lower part of the study area.

The present paper describes the diversity and state of conservation, determinate by a rapid biological inventory, carried out since October 24 to 30 of 2005, at the Amazonian waterbodies from Northeast of Peru, between 680 and 133 m of altitude, among Tarapoto (San Martin) and Yurimaguas (Loreto). Data and samples were collected in 26 stations. Planckton samples were collected with standard net (40 microns), benthos with Surber net and fishes with small mesh seines. Descriptions of each habitat included coordinates (UTM), and limnological characteristics (pH, temperature, conductivity, oxygen). The richness of species of fishes was of 95, dominated by Characiformes and Siluriformes. Richness of species in phytoplankton was of 74, in zooplankton, 22 species and in benthos of 20 species. The conservation state was determined using the Index of Biological Integrity (IBI) for fishes, and EPT...

En el presente trabajo se aplican índices biológicos de calidad ambiental y conservación, basados en el monitoreo biológico realizado entre año 2003 y 2009, en cinco localidades del río Bajo Urubamba. Fueron estudiadas las comunidades del plancton, bentos y peces. La diversidad del plancton comprendió 170 especies, basadas principalmente en Chlorophyta y Bacillariophyta. El bentos incluyó 112 especies, principalmente larvas y adultos de Arthropoda (Insecta). La diversidad de peces, incluye 176 especies, representadas por 26 familias y seis órdenes. El Índice Ephemeroptera + Plecoptera + Trichoptera (%EPT), califico el área de estudio entre normal a muy buena calidad. El índice de Integridad Biológica (IBI) que determina el estado de conservación de los ambientes acuáticos, dio los mayores valores en Miaría y Sepahua. La elevada diversidad de las comunidades estudiados est...

The present paper describes the diversity and state of conservation, determinate by a rapid biological inventory, carried out since October 24 to 30 of 2005, at the Amazonian waterbodies from Northeast of Peru, between 680 and 133 m of altitude, among Tarapoto (San Martin) and Yurimaguas (Loreto). Data and samples were collected in 26 stations. Planckton samples were collected with standard net (40 microns), benthos with Surber net and fishes with small mesh seines. Descriptions of each habitat included coordinates (UTM), and limnological characteristics (pH, temperature, conductivity, oxygen). The richness of species of fishes was of 95, dominated by Characiformes and Siluriformes. Richness of species in phytoplankton was of 74, in zooplankton, 22 species and in benthos of 20 species. The conservation state was determined using the Index of Biological Integrity (IBI) for fishes, and EPT...

This paper reports on the diversity of fish in the lower basin of the Nanay River, a tributary of the Amazon River. This area is subjected to indiscriminate harvesting of fish for ornamental purposes and for direct consumption. Using trawl nets (10 x 2.5 m, 5 mm mesh), we fished in the dry season (August and September 2007) and wet season (February 2008) in three places in the Nanay River. 1626 individuals were collected, corresponding to 86 species of 23 families and five orders. The number of species varied between 13 and 21 in the dry season and between 18 and 26 species during the growing season. Characiformes, Siluriformes and Perciformes were the dominant orders. 76% of individuals had small sizes. 65% of the recorded species have ornamental use.

The main purposes of this study were to know the diversity of fishes in the Inambari river basin, at Mazuco district, (Madre de Dios) and the state of conservation of the aquatic habitats. Samples were collected from 22 stations using seines of small mesh (5mm) and recording data from each habitat. Taxonomic composition of fishes, diversity and abundance, ecological characterization by altitudinal range, habitat and water type; and the conservation state of each water bodies have been studied. A total of 1411 individuals were collected and four orders, 13 families, 35 genera and 52 species were identified. The groups with more diversity were Characiformes (65%) and Siluriformes (25%). Three new records for Peru: Serrapinnus notomelas, Pseudopimelodus bufonius y Pseudocetopsis gobiodes and one endemic species: Chaetostoma marcapatae have been register. The altitudinal pattern influence in...

El presente trabajo informa sobre la diversidad de peces en la cuenca baja del rio Nanay, tributario del río Amazonas. Esta zona está sometida a la extracción indiscriminada de peces con usos ornamentales y de consumo directo. Utilizando redes de arrastre (10 x 2,5 m, 5 mm de luz de malla), se realizaron capturas en época de vaciante (agosto y setiembre de 2007) y creciente (febrero de 2008), en tres lugares del rio Nanay. Se colectaron 1626 individuos, correspondientes a 86 especies, de 23 familias y cinco órdenes. El número de especies vario entre 13 y 21 en época de vaciante y entre 18 y 26 especies en época de creciente. Predominaron los Characiformes, Siluriformes y Perciformes. El 76% de los individuos con tamaños menores de 10 cm. El 65% de las especies registradas tienen uso ornamental.

The main purposes of this study were to know the diversity of fishes in the Inambari river basin, at Mazuco district, (Madre de Dios) and the state of conservation of the aquatic habitats. Samples were collected from 22 stations using seines of small mesh (5mm) and recording data from each habitat. Taxonomic composition of fishes, diversity and abundance, ecological characterization by altitudinal range, habitat and water type; and the conservation state of each water bodies have been studied. A total of 1411 individuals were collected and four orders, 13 families, 35 genera and 52 species were identified. The groups with more diversity were Characiformes (65%) and Siluriformes (25%). Three new records for Peru: Serrapinnus notomelas, Pseudopimelodus bufonius y Pseudocetopsis gobiodes and one endemic species: Chaetostoma marcapatae have been register. The altitudinal pattern influence in...

Chira River is located on the north coast of Peru. The lack of knowledge of the ichthyofauna from coastal drainages from Peru is noteworthy. The aim of this study is to characterize the ichthyofauna along the Chira River basin in terms of diversity and altitudinal range distribution. The material examined belongs to the Ichthyological collection of the Natural History Museum (MUSM). The diversity of fishes is composed of 27 species belonging to 19 families and ten orders. Siluriformes and Characiformes were the most diverse, consisting of 22% (six species) for each one. Five species are new records for the Chira River (three natives and two non-natives). Six marine species and seven exotic species were recorded as well. The altitudinal distribution patterns for all species were registered. This study increases the known diversity of freshwater fishes from Pacific Drainage Rivers in Peru,...

This paper reports on the fish diversity in the lower Pachitea River basin. In July 2005 a rapid inventory in 31 field stattions (14 rivers, 13 streams and 4 lagoons) was conducted. The area was located between Honoria (456195E, 8830474N) and Zungaro (486747E, 8965585N) between the departments of Huanuco and Ucayali. Fishes were caught using seines (4 mm, mesh), and 3967 were captured. 116 species, 25 families and eight orders were identified. Characiforms (59%), Siluriforms (22%) y Perciforms (12%) had the greatest richness. Commercial fishes as Cichla monoculus, Prochilodus nigricans, Salminus hilari, Hoplias malabaricus, Liposarcus sp., Plagioscion squomosissimus and ornamentals as Heros severus, Corydoras stenocephalus, Mesonauta festivus, Pyrrhulina brevis were fished too. Analysis of the richness by types of habitats showed that the streams were more diverses (64 species) than rive...

This paper is a report of ichthyoplankton community and the description of fish larvae from the beginning of River Madre de Dios, in special on the family Pimelodidae. The collections were carried out between November and December of 2004, utilizing a ichthyoplankton net (300 microns of mesh), in 8 transects that covered an approximate section of 2 km upstream and downstream of the Puerto Maldonado city. A total of 83750 larvae were examined, the highest abundance was displayed by Characiformes (81%), followed by Siluriformes (18%). In the Pimelodidae family, 12 commercial species of consumption, emphasizing Pseudoplatystoma tigrinum, P. fasciatum y Sorubim lima. The main orders in ichthyoplankton follow a pattern of relative abundance similar to the adult state. The presence of larvae of great catfishes migratory (Pimelodidae family) in the zone of sampling suggests this region of the...

The ichthyological diversity of the Mayapo stream is described based on material from the Ichthyological Collection of the Natural History Museum of the Universidad Nacional Mayor de San Marcos (UNMSM). We analysed material from 30 sample points of the Mayapo stream and tributaries, collected in 2005, 2009, and 2012. The points were located between 256 and 557 m of altitude. A total of 60 species grouped in 39 genera, 16 families, and four orders were identified. The Characiformes and Siluriformes orders including the Characidae and Loricariidae families were the most representative groups. We concluded that total ichthyological diversity in Mayapo stream and tributaries was moderated compared with previous studies in the Peruvian Amazon. Additionally, the taxonomic composition showed the common diversity pattern found in the Neotropical freshwaters and Peruvian Amazon. Finally, we also ...

El presente trabajo informa sobre la diversidad de peces en la Cuenca del Bajo Pachitea. En julio de 2005 un inventario rápido en 31 estaciones (14 ríos, 13 quebradas y 4 lagunas) fue realizado. El área comprendió entre Honoria (456195E, 8830474N) y Zúngaro (486747E, 8965585N) entre los departamentos de Ucayali y Huánuco. Para la colecta se utilizaron redes de arrastre a la orilla, obteniéndose un total de 3967 individuos. Se identificaron 116 especies reunidos en 25 familias y 8 órdenes. La mayor riqueza la tuvieron Characiformes (59%), Siluriformes (22%) y Perciformes (12%). Se registraron especies de consumo humano como: Cichla monoculus, Prochilodus nigricans, Salminus hilari, Hoplias malabaricus, Liposarcus sp., Plagioscion squamosissimus; peces ornamentales: Heros severus, Corydoras stenocephalus, Mesonauta festivus, Pyrrhulina brevis. El análisis de riqueza por tipo de h�...

This paper is a report of ichthyoplankton community and the description of fish larvae from the beginning of River Madre de Dios, in special on the family Pimelodidae. The collections were carried out between November and December of 2004, utilizing a ichthyoplankton net (300 microns of mesh), in 8 transects that covered an approximate section of 2 km upstream and downstream of the Puerto Maldonado city. A total of 83750 larvae were examined, the highest abundance was displayed by Characiformes (81%), followed by Siluriformes (18%). In the Pimelodidae family, 12 commercial species of consumption, emphasizing Pseudoplatystoma tigrinum, P. fasciatum y Sorubim lima. The main orders in ichthyoplankton follow a pattern of relative abundance similar to the adult state. The presence of larvae of great catfishes migratory (Pimelodidae family) in the zone of sampling suggests this region of the...

The ichthyological diversity of the Mayapo stream is described based on material from the Ichthyological Collection of the Natural History Museum of the Universidad Nacional Mayor de San Marcos (UNMSM). We analysed material from 30 sample points of the Mayapo stream and tributaries, collected in 2005, 2009, and 2012. The points were located between 256 and 557 m of altitude. A total of 60 species grouped in 39 genera, 16 families, and four orders were identified. The Characiformes and Siluriformes orders including the Characidae and Loricariidae families were the most representative groups. We concluded that total ichthyological diversity in Mayapo stream and tributaries was moderated compared with previous studies in the Peruvian Amazon. Additionally, the taxonomic composition showed the common diversity pattern found in the Neotropical freshwaters and Peruvian Amazon. Finally, we also ...

The taxonomic status of Gastrotheca peruana is evaluated using phylogenetic methods and 16S gene sequences. The maximum likelihood and Bayesian trees showed that the genetic variants of G. peruana form two clades that are not sister to each other. One of these clades is present in northern Perú and includes a specimen collected at the type locality of G. peruana dissimilis. The other clade is restricted to central Peru and contains individuals from type localities of two nominal forms, G. p. peruana and G. p. junensis, and is sister to G. aratia. Our results suggest that G. peruana sensu lato currently encompass two species. We restrict Gastrotheca peruana to populations from central Perú (departments of Ancash, Lima, Pasco and Junín) and assign populations from departments of La Libertad and Cajamarca to Gastrotheca dissimilis.

The taxonomic status of Gastrotheca peruana is evaluated using phylogenetic methods and 16S gene sequences. The maximum likelihood and Bayesian trees showed that the genetic variants of G. peruana form two clades that are not sister to each other. One of these clades is present in northern Perú and includes a specimen collected at the type locality of G. peruana dissimilis. The other clade is restricted to central Peru and contains individuals from type localities of two nominal forms, G. p. peruana and G. p. junensis, and is sister to G. aratia. Our results suggest that G. peruana sensu lato currently encompass two species. We restrict Gastrotheca peruana to populations from central Perú (departments of Ancash, Lima, Pasco and Junín) and assign populations from departments of La Libertad and Cajamarca to Gastrotheca dissimilis.

An annotated species fish list recorded in the Aguaytía River basin is presented. Fishes were collected between 1942 and 2009 in different years and seasons. This is the first inventories in Aguaytía river Basin, and for the Cordillera Azúl National Park. Fishes were mainly collected using seines of 10x3 m and of 5x2 m and 6 mm mesh. For fixation and preservation of samples were used 10% formaldehyde solution and 70% ethanol, respectively. Samples are in the Ichthyological Collection (MUSM) of the Museum of Natural History of San Marcos University. We analized 9917 specimens and recorded a total of 211 species of 28 families and nine orders.

El estudio presenta una lista comentada de especies de peces registradas en la cuenca del río Aguaytía. Son consideradas las colectas de diferentes años y estaciones climáticas entre 1942 y 2009. Es el primer inventario de los peces para esta cuenca, la cual es importante para el Parque Nacional Cordillera Azul. La metodología empleada para la recolección de las muestras incluyó principalmente colectas activas con redes de arrastre de 10x3 m y de 5x2 m y 6 mm de malla. La fijación y preservación de las muestras se realizo con formol al 10% y de etanol al 70%, respectivamente. Las muestras se encuentran en la Colección Ictiológica (MUSM) del Museo de Historia Natural de la Universidad Nacional Mayor de San Marcos. Fueron analizados 9917 ejemplares y registradas un total de 211 especies agrupadas en 28 familias y nueve órdenes.

This study presents an updated checklists of the fish species recorded in the Ucayali River basin, Peru, from published and unpublished data. Ucayali River basin shows a rich and diversified ichthyofauna, with 734 species distributed in 15 orders, 49 families and 292 genera. It is composed by miniature fishes (4 %, < 2.6 cm of standard length), small fishes (39 %), medium fishes (41 %), large fishes (13 %) and giants (3 %). The dominant groups are Characiformes (312 species, 43.0 %), Siluriformes (270 species, 36.8 %), Gymnotiformes (51 species, 6.9 %) and Cichliformes (50 species, 6.8 %). Part of the ichthyofauna is shared with the adjacent basins as Marañón and Amazon, mainly in the confluence area, which contribute to the highest diversity of fishes in the Ucayali basin. High diversity of fishes with restricted distribution was observed, among them Orestias, Astroblepus, Trichomy...