Morphology and Morphometry of the Brain of African side necked turtle (Pelusios castaneus): A Preliminary Investigation

Abstract

The brain and spinal cord make up the central nervous system and studying its morphology and morphometry in African side necked turtle (Pelusios  castaneus) enhance understanding the neurobiology of this reptile. The current study is aimed to document the normal features on gross morphology  and morphometry of the brain of Pelusios castaneus, and discuss the structure-function paradigm. The study was conducted on six (6) brains of African  side necked turtle without sex differences. The main morphologic features observed were: 1- a pear-shaped olfactory brain, sand-wished between the  two eyes and grossly divided into i) olfactory bulb, ii) olfactory tract and iii) olfactory lobe. 2- smooth cerebrum lacking gyri and sulci, and narrowed  rostrally but broad caudally, 3- bi-lobed optic structure separating the cerebrum from cerebellum, 4- developed cerebellum with large corpus cerebelli  and small flocculus. 5-pons and medulla oblongata were developed, and made up the myelencephalon. The mean body, head and brain weights were  111.69±21.04g, 4.58±0.60g and0.35±0.04g respectively. While brain weight accounts for 0.34% of total body weight and 8% of head weight, brain somatic  index was 0.0034±0.0004 and head brain index was 7.60±0.70 respectively. The study provided baseline data on the gross morphology and morphometry  of the brain of African side necked turtle (Pelusios castaneus); which is of great benefit in understanding the neurobiology of this reptile.