Volumetric analysis of the brain of sharpnose sharks, Rhizoprionodon lalandii and Rhizoprionodon porosus (Chondrichthyes: Carcharhinidae)

• Grant number: 15/17288-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2015
• End date: July 31, 2016
• Field of knowledge: Biological Sciences - Zoology - Morphology of Recent Groups
• Principal Investigator: Otto Bismarck Fazzano Gadig
• Grantee: Juliana Thiemy Kina
• Host Institution: Instituto de Biociências (IB-CLP). Universidade Estadual Paulista (UNESP). Campus Experimental do Litoral Paulista. São Vicente , SP, Brazil

Abstract

This study intend to analyse the volume of the brain areas related to sensory organs in the sharpnose sharks, Rhizoprionodon lalandii and Rhizoprionodon porosus, to assess intra and inter ontogenetic differences. For each specimen, the brain will be exposed by cirurgical incision to delimitation of the sensory areas, as follows: telencéfalo, teto óptico, bulbos olfatórios, cerebelo and two lateral line areas. For each region the volume will be calculated according the geometric figures which is more similar to its shapes and measured the length, widht and height, by calliper, stereomicrocopy and digital images (analysed by the Image J software). The statistical analysis will be performed by the PRIMER softare and the data tranformed in proportions of the total brain volume, standardized and submetidos a análises de componentes principais (PCA). Such data will be employed in a matriz de similaridade based in Euclidian distances e será realizada análise de similaridade (ANOSIM), com adição dos fatores "maturidade" e "espécie". Caso sejam encontradas diferenças significativas, será realizada uma análise de similaridade de porcentagens (SIMPER) para que se determine o percentual da contribuição de cada área sensorial.