Trypanosoma danilewskyi: host specificity and host's effect on morphometrics.

Carassius auratus, Barbus conhus, Danio malabaricus, Catostomus commersoni, Notropis cornutus, Etheostoma caeruleum, and Ictalurus nebulosus were susceptible to Trypanosoma danilewskyi by intraperitoneal inoculation. Trypanosomes isolated from all species of susceptible fishes were infective to goldfish. No trypanosomes were detected in inoculated Semotilus atromaculatus, Ambloplites rupestris, Lepomis gibbosus and Perca flavescens. Fifty specimens were measured from each of 3 C. auratus, 2 B. conhus, 2 C. auratus inoculated with an isolate from a C. commersoni, 2 C. commersoni, and 2 E. caeruleum, for statistical analyses. The distance of the kinetoplast from the posterior end, length of free flagellum, nuclear length, and area of nucleus were similar among samples from the same host but differed significantly among samples from different host species. After discriminate analysis, samples from goldfish clustered into a tight group while those from the other fishes formed a loose cluster along the first canonical axis. Using the jacknife method of correct classification, 93% of trypanosomes from C. auratus, 36% from C. commersoni, 61% from C. commersoni-C. auratus, 25% from B. conhus, and 40% from E. caeruleum, could be correctly assigned to host species. However, only 1% of trypanosomes from C. commersoni would be classified as coming from C. auratus, 4% for C. commersoni-C. auratus, 0% for B. conhus, and 7% for E. caeruleum.