Abstract

Necrophagy is the feeding behaviour of organism that feed on carrion. The decaying flesh of dead animals is an important food source for necrophagous organisms in most ecosystems. The time of arrival and the growth rate of organisms inhabiting carrion are used to determine circumstances surrounding deaths. Studies on necrophagous organisms associated with Gallus gallus domesticus carrion provide useful data to estimate the post-mortem interval in forensic cases. The present study was undertaken to determine the abundance of some forensically important organisms on the carrion of chicken buried at different depths namely, 0.6 m, 1.21 m and on the soil surface in six successions in Abraka, Delta State Nigeria. Entomological, parasitological, and microbiological analyses were carried out on the carrion by standard procedures. Site climatic factors such as temperature and relative humidity were recorded using a digital thermo-hygrometer. A total of 417 necrophagous organisms were isolated from the carrion. Among the insects, three orders comprising nine families and sixteen species were encountered. The highest number of insects were observed among members of the Saprinus chalcites 103.0(24.70%), followed by Streblognathus aethiopicus 71(17.03%), Xerosaprinus species 58(13.91%), Musca domestica 35(8.39%), Onitis 33(8.0%), Bryocharis 24(5.76%), Piesocorynus lateralis 22(5.38%), Chrysomya species 20 (4.80%), Heteronychus arator 17(4.08%), Solenopsis species 16 (3.84%), Trochosa species 5 (1.20%), Diaparis species 3(0.72%), Marganinotus feedatus 3(0.72%), Phalacridae species 3(0.72%), and Eparea species 1(0.24%). Statistically, there was a difference (p<0.05) in the relative abundance of the necrophagous arthropods collected. There was no significant difference in the relative abundance of the organisms collected on the surface soil and the different soil depths. Relative humidity had a significant effect on the abundance of fauna obtained as it was correlated positively with the relative abundance of the organisms (r=0.941). The parasites collected were Hymenolepis nana, Capilaria contorta, Ascaris gallus, and Eimeria tenella. The bacteria isolated were Klebsiella Pneumoniae, Streptococcus pneumoniae, Escherichia coli, Staphylococcus auerus, Pseudomonas aeruginosa, and Bacillus cereus. The fungi isolated from the carrion were Aspergillus niger, Aspergillus flavus, Penicillium sp., Aspergillus fumigatus, Rhizopus, Trichosporon asahii Scedosporium aurantiacum, Chrysosporium tropicum and Lecytophora sp. It is hoped that the data in this will contribute to postmortem and forensic investigation in our locality.