Morphometric stepwise discriminant analysis of three genetically identified species within Pseudoterranova decipiens (Krabbe, 1878) (Nematoda: Ascaridida)

Univariate and multivariate statistical analyses have been performed on 19 morphometric variables of adult male specimens belonging to three genetically identified species within Pseudoterranova decipiens (Nematoda: Ascaridida) parasitic in the digestive tract of seals. Two morphometric keys are proposed for the identification of the three species. One key, which uses two variables, determines a frequency of error of 3.8% (3/79). The second key, which uses two canonical discriminant functions based on seven variables previously selected with a “stepwise” procedure, gives 100% (76/76) accurate classification.