A preliminary study of insect, bacterial, and fungal communities associated with Sus scrofa carrion in a tropical rainforest.

Abstract

Carrion decomposition is an important component of the ecosystem and plays a significant ecological role in the food chain. During decomposition, arthropods and microorganisms help to decompose and recycle organic matter and nutrients. Although research has been conducted on microorganisms and arthropods associated with carrion across different biogeoclimatic ecoregions, no study has identified these communities from carrion placed under a tropical rainforest. Therefore, this study aims to investigate the arthropod, bacterial, and fungal communities associated with Sus scrofa Linnaeus. carrion placed in a tropical rainforest in Malaysia. Adult flies and maggots and other arthropods were collected during the forensic entomological survey. The specimens collected were killed, separated, preserved in 70% ethanol, and identified using a stereomicroscope in the laboratory. Swab samples were collected from the skin, anal, and oral cavity of the wild boar carrion. Both bacterial and fungal communities were identified using Sanger sequencing. Data on temperature and humidity were recorded with a data logger throughout the four-day experiment. The results demonstrated that the most isolated bacteria were those of uncultured_bacteria, Ignatzschineria sp. and Gram-negative bacteria, especially Acinetobacter sp., during the early stages of decomposition. Furthermore, the consistent presence of Ascomycota fungi, particularly Exophiala sp., Yarrowia sp., and Meyerozyma sp., suggests their unique occurrence specifically in the tropical rainforest. A total of 219 adult flies and about 9,200 larvae were collected from a wild boar carcass over three days, with Chrysomya pinguis and Chrysomya villeneuvi being the main species, and the latter displaying notable predatory behaviour. These results present for the first time the dominant arthropods, bacteria and fungi inhabiting the carrion in one of the oldest rainforests in the world. (Keyword: Carrion, decomposition, bacteria, fungi, arthropods, tropical rainforest, Malaysia).