Habitat changes affecting Bacterial composition in the alimentary canal of oribatid mites (acari: oribatida)

Abstract

Abstract Bacteria in the alimentary canals of two oribatid mites, Rhysotritia sp. and Pergalumna sp., were examined from three different habitats. The three habitats included the mites'natural habitat and two artificial laboratory habitats, one with food and one without food. Gut microorganisms were obtained by dissecting paraffin-embedded, surface sterilized mites. Each alimentary canal and its contents, removed during dissection, were inoculated into 10 microbiological culture media. Bacteria, isolated from the oribatid gut, included: Bacillus, Pseudomonas, coryneforms, actinomycetes, Mycobacterium, Alcaligenes, Flavobacterium, Acinetobacter, and Citrobacter. Microorganisms from moss-soil samples of the oribatids natural habitat and laboratory foods were obtained and identified for comparison. The microorganisms in the oribatid gut significantly (P < 0.05) changed with the oribatid species and with the oribatids' habitats. Rhysotritia and Pergalumna taken directly from the natural habitat and dissected, contained significantly lower frequencies of Bacillus and Pseudomonas isolations than those found in the moss-soil samples. After laboratory maintenance with food, dramatic shifts in the frequency of Bacillus and Pseudomonas were noted from both mites. A variety of bacteria were obtained from both oribatid species which had been starved for a period of 13 days.