The comparative gastrointestinal morphology of Jaculus jaculus (Rodentia) and Paraechinus aethiopicus (Erinaceomorpha)

Abstract

Jaculus jaculus (Lesser Egyptian jerboa) and Paraechinus aethiopicus (Desert hedgehog) are small mammals which thrive in desert conditions and are found, amongst others, in the Arabian Peninsula. J. jaculus is omnivorous while P. aethiopicus is described as being insectivorous. The study aims to describe the gastrointestinal tract (GIT) morphology of these animals which differ in diet and phylogeny. The GITs of J. jaculus (n=8) and P. aethiopicus (n=7) were weighed, photographed, and the length, basal surface areas and luminal surface areas of each of the anatomically distinct gastrointestinal segments were determined. The internal aspects of each area were examined and photographed while representative histological sections of each area were processed to wax and stained using haematoxylin and eosin. Both species had a simple unilocular stomach which was confirmed as wholly glandular on histology sections. P. aethiopicus had a relatively simple GIT which lacked a caecum. The caecum of J. jaculus was elongated, terminating in a narrow cecal appendix which contained lymphoid tissue on histological examination. The internal aspect of the proximal colon revealed distinct V-shaped folds. Stomach content analysis of J. jaculus revealed mostly plant and seed material and some insects, whereas P. aethiopicus samples showed plant material in addition to insects, indicating omnivorous feeding tendencies in areas where insects may be scarce.