Analysis of the extracutaneous pigmentation of two populations of Physalaemus cuvieri (Anura: Leptodactylidae) and its correlation with abiotic factors

• Grant number: 16/04125-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2016
• End date: June 30, 2017
• Field of knowledge: Biological Sciences - Zoology - Morphology of Recent Groups
• Principal Investigator: Classius de Oliveira
• Grantee: Nayara dos Anjos Vicente
• 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 anurans have an extracutaneous pigmentary system, composed of melanocytes, which have an intense pigmentation and are responsible for the melanin's synthesis, and melanomacrophages, with phagocytic activity. These pigments are found in liver, spleen, kidneys, peritoneum, lungs, heart, blood vessels, thymus, gonads and meninges. The pigmentary system can be changed due to environmental stimuli and internal conditions. Based on this, this study aims to evaluate changes in the visceral surface pigmentation and in the liver histology of two populations of Physalaemus cuvieri. The animals will be collected and euthanized to expose the abdominal cavity, which will be photographed in stereoscopic microscope. The pigmented organs will be identified and classified according to the amount of pigment. Liver fragments will be collected and, then, will be submitted to histological routine to quantify melanin. Furthermore, the pigmentation pattern of the pericardium's iridophores will be evaluated. The data obtained will be subjected to statistical analysis of normality and homogeneity, followed by analysis of variance. Additionally, we will analyze the correlation between the amount of liver's melanin and environmental factors that will be measured in the field (UV radiation, humidity, temperature and photoperiod) and environmental contaminants in water wells in the collection sites. Thus, the pigmentation pattern of the species will be evaluated, as well as the effects of environmental quality in the anuran's liver pigmentation in two different locations, so that the differences among populations will be detected. (AU)