We have previously shown that population parameters of the trematode metacercariae of Clinostomum marginatum in black bass (Micropterus spp.) were closely correlated with each other with the exception of prevalence (Daly et al. 2007, Daly (2014). Crofton (1971) and Haynes and Nicholas (1963) published raw data on an acanthocephalan, (Polymorphus minutus) in an amphipod intermediate host collected on 6 different sites on a stream. That data was used herein to examine similar correlations, as with Clinostomum, to see if another helminth infection, in this case from a different phylum, also had similar descriptor relationships. Forty one regression analyses were done on parameter data from the populations of P. minutus as described by Crofton and Haynes and Nichols. Descriptors used were mean abundance and standard deviation, maximum number, prevalence, mean intensity and standard deviation, dispersion coefficient, and skewness and kurtosis (shape parameters of the population curves). Results showed that the parameters most usually reported to describe helminth infections were, as with Clinostomum, strongly correlated with each other. One difference being prevalence, in which P. minutus prevalence was significantly correlated with other parameters. Dispersion coefficients (standard deviation/mean) were independent (not significant) of an effect by the other parameters. Skewness and kurtosis were very highly correlated within the two population types (mean and mean intensity) but not with other descriptors. Since population parameters are important in the description of parasitic infections, it would seem that more data on more helminths are needed to determine if this proportionality is a universal phenomenon of stochastic and random helminth infections or just coincidentally found in C. marginatum and P. minutus juvenile infections.
Daly, J. J. Sr. and Wagner, K.
"Proportionality Between Population Descriptors (Covariables) in an Aggregated Acanthocephalan (Helminth) Infection of a Microcrustacean: Crofton Revisited,"
Journal of the Arkansas Academy of Science: Vol. 70
, Article 15.
Available at: http://scholarworks.uark.edu/jaas/vol70/iss1/15