Microparasite Assemblages of Conspecific Shrew Populations in Southern California

Abstract

The microparasite component communities of 2 species of shrews, Notiosorex crawfordi and Sorex ornatus, were investigated for the first time in 2 isolated and 3 continuous landscapes in southern California. With microscopical examination, a total of 6 parasite species was found in N. crawfordi and 8 species in S. ornatus. The highest number (5) of parasite species was detected in the lungs. The corrected estimate of parasite species richness did not significantly correlate with the host abundance in either shrew species. Altitude, and also latitude in N. crawfordi, appeared to be significantly positively associated with the parasite species richness, but this could be due to a false association because of the rare occurrence of some of the parasites or the small altitude range (or both). No other landscape variable analyzed (location, size of the study site, disturbance) was significantly associated with the parasite species richness of the shrews. The parasite assemblages of the 2 shrew species were similar despite the fact that N. crawfordi has a lower metabolic rate than S. ornatus.

Helminth parasites of Xiphophorus birchmanni (Pisces: Poeciliidae) from two localities of the Pánuco River drainage, Mexico

“…Finally, it has been shown that there is a correlation between altitude and species richness in most taxa (Laakkonen et al, 2003); a factor that could contribute to the differences in the helminth communities of the 2 species is a greater availability of intermediate hosts in downstream localities compared to upstream ones. Blasco-Costa et al (2013) observed a correlation between the abundance of digeneans infecting fish and river flow, and found that parasites were more abundant downstream, which they attributed to the downstream flow of water favoring the displacement and dispersion of invertebrates (including both intermediate hosts and infective stages of the helminths).…”

Flea (Siphonaptera) species richness in the Great Basin Desert and island biogeography theory

“…For example, species richness of ectoparasitic mites on some rodents is correlated with host range (Dritschilo et al , O'Connor et al ), and parasite species richness of fissiped carnivores is correlated with host body mass, host population density, and host geographic range (Lindenfors et al ). However, parasite species richness of freshwater fish is not correlated with host range (Guegan and Kennedy ), for shrews is not correlated with population density (Laakkonen et al ), and for bats is not correlated with host body size, but is with population density.…”