Genocytotoxicity of the Fiddler Crab, Leptuca thayeri (Rathbun, 1900), in Two Mangrove Areas with Different Levels of Anthropogenic Impact.

• Grant number: 24/16114-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2025
• End date: December 31, 2025
• Field of knowledge: Biological Sciences - Zoology - Morphology of Recent Groups
• Principal Investigator: Marcelo Antonio Amaro Pinheiro
• Grantee: Elizabete Nascimento dos Santos
• Host Institution: Instituto de Biociências (IB-CLP). Universidade Estadual Paulista (UNESP). Campus Experimental do Litoral Paulista. São Vicente , SP, Brazil

Abstract

Mangroves are ecosystems of extreme importance to coastal regions. Still, they are being severely affected by increasing human population density and associated activities, negatively impacting both the environment and biota. Given this, environmental monitoring tools are essential to understand these environmental damages. Recently, decapod crustaceans have been used as sentinel species due to their sensitivity to changes in environmental quality. Furthermore, using effect biomarkers has proven highly effective, allowing the detection of pre-pathological damage in organisms. Among these, the neutral red retention assay (NRRT) stands out, as it quantifies cellular functional viability by measuring the retention time of the dye in hemocyte lysosomes, indicating cytotoxicity. The micronucleus test (MN¿), on the other hand, quantifies the frequency of micronucleated hemocytes, revealing genotoxicity. These biomarkers efficiently detect xenobiotics' effects and assess areas with different levels of anthropogenic impact. This study aims to evaluate the efficiency of Leptuca thayeri as a sentinel species for environmental quality in mangroves, comparing two areas in the State of São Paulo: a pristine area (Juréia-Itatins Ecological Station) and an impacted area (Itanhaém Estuarine System). These genocytotoxic analyses are unprecedented for the target species. Adult males (n = 12 per area) will have their hemolymph collected, processed, and analyzed to assess the health of the organisms. Statistical analyses will be performed using the t-test (Student) or Wilcoxon test, revealing potential significant contrasts between these areas at a 5% significance level.