This study documents for the first time the coexistence of Loxosceles laeta and Hadruroides lunatus in Peru. The research was conducted at the Universidad Nacional Mayor de San Marcos, Lima, during June 2024. Visual inspection methods and rock lifting were employed to record individuals of both species, measuring the distances between them. Previous observations conducted in 2023 revealed reduced interactions during the summer, suggesting seasonal influences.

The present study compiles data from 292 lots, of which 4 lots with 45 specimens belong to Belonion dibranchodon (Collette, 1966), 190 lots with 324 specimens to Pseudotylosurus angusticeps (Günther, 1866), 53 lots with 124 specimens to Potamorrhaphis eigenmanni (Ribeiro, 1915), and for Potamorrhaphis guianensis (Jardine, 1843), 40 lots with 108 specimens were recorded. The identification of taxa was corroborated after compiling taxonomic keys. Subsequently, the standard length of specimens was measured, and distribution maps were generated using DIVA-GIS. The results showed significant diversity in the Peruvian Amazon, with B. dibranchodon present in the Putumayo basin in Loreto, Potamorrhaphis distributed in Loreto, Ucayali, and Madre de Dios, and P. angusticeps with a wide distribution in several basins. The absence of Pseudotylosurus microps in the collection suggests the need for f...

This study examines the populations of anthropic rodents of the Muridae family at the Universidad Nacional Mayor de San Marcos (UNMSM), Lima, Peru with the aim of identifying the species present and their relationship with the environment. Twenty individuals were captured, distributed in Mus musculus (Linnaeus, 1758) (85%), Rattus rattus (Linnaeus, 1758) (10%) and Rattus norvegicus (Berkenhout, 1769) (5%). The 60% were males, 5% females, and 35% were not identified due to their escape. Two areas were analyzed: "Green area behind the dining room" and "Area adjacent to the Huaca (archaeological site)", where M. musculus predominated in both. The analysis of the feces revealed plant remains, animal remains and plastics; while the evaluation of the environmental components showed that different plant families influence the presence of rodents. The results suggest that environmental component...