Infestations of the nematode Skrjabingylus nasicola (Leukart 1842) in Mustela frenata (Lichtenstein) and M. erminea (L.) and some evidence of a paratenic host in the life cycle of this nematode

Abstract

Examination of 153 Mustela frenata and 16 Mustela erminea from Manitoba revealed 100% parasitism of both hosts by Skrjabingylus nasicola. Cranial damage was significantly less in M. frenata than in M. erminea. In M. frenata, cranial damage was less in adult females than males and greater in adults than in subadults. Adult males and females had a greater degree of damage than subadult males and females. Percentage infestation and damage was related to diet. Data suggest that rodents, particularly the myomorphs, shrew, amphibians, and reptiles are paratenic hosts for S. nasicola. The condylobasal length of the skull of M. frenata apparently is not affected by parasite invasion, though the interorbital breadth is affected and becomes unreliable as a taxonomic measurement. Cranial damage was frequently asymmetrical. Despite repeated invasions, the definitive host is still active and therefore must tolerate the damage.