The appendicular skeleton of the Eidolon helvum (African fruit bat): Gross anatomical investigations
Appendicular skeleton of Eidolon helvum
Keywords:
Eidolon helvum, fore- and hind-limb skeleton, morphology, osteologyAbstract
The bats are the only known flying mammals. The skeleton is an essential aspect of anatomy and the shape and characteristics of each bone is peculiar to each animal species. Despite the widespread distribution of the African fruit bat (Eidolon helvum), there is no documented data on the morphometrics and description of the skeleton, apart from the axial skeleton documented by this team. This study therefore aims at highlighting the gross description of the individual bones of the appendicular skeleton – fore and hind limbs – of the Eidolon helvum captured from the wild. The bats (5 males, 10 females) were captured from the southwestern part of Nigeria used for this study. They were humanely sacrificed, de-fleshed and subjected to cold maceration. The appearance of the individual bones was unique. Of particular interest were the scapula, ossa coxarum and the metacarpal bones. Similar to neotropical bats, the scapula had a strong similarity in shape and appearance to the human counterpart, while differing greatly from other mammals and avians. The ossa coxarum was the only bone that showed a distinct sexual dimorphism. The shape of the obturator foramen was ovoid in males but more triangular in females. Also, there was non-fusion of the pubic symphysis in the females, unlike that observed in males. The metacarpal was not observable in all subjects, as the carpal bones were seen to articulate directly with the digits distally, and the ulna proximally. Linear measurement results obtained showed that the males had generally higher values, with the wingspan (609.96±64.53 mm) showing a statistically significant difference between the genders (P<0.05), males being 663.45±14.48 mm, and the females 580.14±62.23 mm. Results obtained from this study provide baseline, data which may find application in basic and comparative anatomical studies, forensic, archaeological and anthropological studies, and wildlife clinical procedures.