Survey of freshwater planarian species (Platyhelminthes, Tricladida) in reservoirs of São José do Rio Preto, northwest of São Paulo state

• Grant number: 24/14182-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2024
• End date: November 30, 2025
• Field of knowledge: Biological Sciences - Ecology - Ecosystems Ecology
• Principal Investigator: Maria Stela Maioli Castilho Noll
• Grantee: Pedro Henrique Santarelli de Oliveira
• Host Institution: Instituto de Biociências, Letras e Ciências Exatas (IBILCE). Universidade Estadual Paulista (UNESP). Campus de São José do Rio Preto. São José do Rio Preto , SP, Brazil

Abstract

The best-known free-living flatworms are the tricladids, popularly known as planarians, which inhabit a wide range of environments, being found on humid land, in the seas and oceans, but with much greater expressiveness in freshwater environments, where they rarely appear in studies of limnic biodiversity. In the Neotropical region, these animals are best studied in southeastern Brazil, which still has several areas never sampled for any tricladids, as is the case of the northwestern region of São Paulo, in the municipality of São José do Rio Preto, which is an unknown and threatened biodiversity, mainly due to the advance of urbanization and the difficulty in identifying the species, which is only possible through histology. In view of this, the project aims to conduct a survey of tricladids in reservoirs in São José do Rio Preto, relying on histomorphological and molecular characterization as a tool for species identification. To this end, planarians will be collected from five reservoirs in the municipality by inspecting the roots and leaves of aquatic plants and also using baited traps. After analyzing the animals in vivo and separating related animals into morphospecies, the planarians will be dehydrated and embedded in paraffin to begin their histological processing. With hematoxylin-eosin staining and trichrome stains such as Masson-Goldner and Azan-Heidenhain-Mallory, it will be possible to observe and describe the genital structures with taxonomic value that will allow identification at the species level. Finally, the isolation of total DNA will allow amplification of the mitochondrial cytochrome oxidase I gene, through which the morphological identification of the species will be corroborated.