Annelida is a large and complex phylum of “worm-like” organisms. Of particular interest is the subclass Oligochaeta, which includes all earthworm species. Earthworms typically contain no visible chaetae, (or bristles), and mature organisms will exhibit an obvious clitellum. A given earthworm will fall into one of three ecotypes (epigeic, endogeic, and anecic) based on burrowing behaviours and general distribution. Earthworm research has value as it relates to soil formation, nutrient cycling, and primary production. This study focused on extraction of earthworms using different non-toxic substances (mustard, cloves, and ginger). Parasite distribution within collected earthworms was also of interest during this study. Gregarines are a myriad group of parasites that are part of the phylum Apicomplexa and closely related to the malaria causing Plasmodium, making them valuable models for study. Monocystis agilis, a member of the gregarine group, infects earthworms specifically and inhabits their reproductive organs. Earthworms were first extracted from soil using non-toxic substances at various sites around the City of Abbotsford. Collected earthworms were dissected and extraction of fluids from their seminal vesicles allowed for quantitative measurement of parasite distribution. A qualitative assessment of parasite lifecycle was then conducted using compound microscopy and an ECHO Revolve microscopic photography unit.
Results/Conclusions
ANOVA test (alpha = 0.05) showed there was strong evidence to suggest the three substances used, mustard, cloves, or ginger, did not extract the same mean number of earthworms (p< 0.05). A Tukey Multiple Comparisons test confirmed this significant difference, suggesting it occurred largely between mustard and ginger. Cloves appeared to have no statistical difference when individually compared to ginger or mustard. These results support current literature that indicate active agents in mustard and cloves such as Allyl isothiocyanate and Eugenol, respectively, are highly effective in irritating the epidermal layers of earthworms. Utilizing this information has value when measuring earthworm abundance as a marker for soil health and ecosystem primary production. A subsequent ANOVA test (alpha = 0.10) focused on parasite distribution showed that parasite load between three locations, farmland, gardens, or parks, was not significantly different (p>0.10). Further analysis of only invasive species parasite load supported the conclusion that parasite load across different locations was not significant (p>0.10). The results obtained for parasite distribution were unexpected and suggest more sampling and larger samples sizes could lead to a better understanding of parasite distribution.