Impact of Exposure Status on the Diversity and Successional Pattern of Cadaverous Arthropods on Slaughtered Juvenile Pig (Sus scrofa Linn.) Carcasses in Wukari, Nigeria

Abstract

Knowledge of successional colonization of cadaver is important in medico-legal studies especially with regards to postmortem interval (PMI) estimation. Paucity of data especially as it relates to juveniles has limited the appropriate application of this knowledge for the benefit of man. To bridge this knowledge gap, juvenile human cadaver was modeled using 2 slaughtered juvenile pigs – Sus scrofa Linn. (≈ 10 kg mean weight) at the study site. One pig was exposed to sunlight while the other shaded under a tree. Both pigs were protected from scavengers and allowed through the decay stages and sampling for adult arthropods continued till the dry-remain
stage of decomposition. Data collected were used to compute frequency of occurrence and relative abundance. Paleontological Statistical Tool (Past3) was used to compute diversity indices. Of the 2032 arthropods of 20 species, across 17 families retrieved, the exposed carcass attracted 44.1% comprising 16 species within 15 families while the shaded carcass attracted 14 species within 12 families. Over 50% species similarity on the contrasting carcasses was observed. Calliphoridae, Muscidae, Dermestidae, Histeridae and Formicidae made-up the dominant families sampled. While Musca domestica L. (Muscidae) and Anochetus sp. (Formicidae) were
exclusively dominant for the shaded carcass, Crematogaster sp. (Formicidae) was exclusively dominant for the exposed carcass. Both carcasses completed decomposition in 14 days but exhibited a shorter advanced-decay stage for the shaded carcass and shorter dry remain stage for the exposed carcass. We thus conclude that, there was little distinction in the diversity and succession pattern of the arthropods colonizing both carcasses (shaded and exposed).