Biometric analysis in Basirolaimus indicus (Sher) Shamsi, 1979 (Nematoda: Hoplolaimidae)


  • M. I. S. Waliullah


In taxonomic studies of phytoparasitic and soil nematodes considerable emphasis is placed on the use of ratios of various body measurements, especially de Man's ratios, though several of them have become useless in the opinion of some workers. Geraert (1968, 1978) considers ratios 'a' and 'b' to be of no value and has also indicated limitations in the use of 'c' and 'V'. As the tail length behaves differently in different tylenchid species, Geraert suggested apparently in the light of Clark's (1962) observation, that « it will be necessary to demonstrate for the particular case studied that the tail-length depends on the body length before the 'c' ratio may be used ». The same is true for the other ratios. Because of the controversy in the use of such ratios, investigations were undertaken on the reliability of ratios of various body parameters in the adults of a natural population of a tylenchid species. The linear dimension of the various sets of measurements of 80 specimens of Basirolaimus indicus (Sher, 1963) Shamsi, 1979, collected from a single habitat, were analysed with the help of some statistical methods.