Section of Nematology, Department of Zoology, Aligarh Muslim University, Aligam-202001 (INDIA).
Biomass of 235 plant-parasitic and soil nematode spies has been determined with the help of Andrassy's formula. The lightest nematode species recorded in this study is Discotylenchus attenuatus Siddiqi, 1980, with biomass of its female and male being 0.0346 and 0.0232 μg, respectively. Longidorus saginus Khan et al., 1971 weighs 15.4983 μg, and is apparently heaviest of all the 235 species. Ratio between the biomass of the former and latter species was found to be 1: 448. This study indicates that biomass is not characteristic of a species and due evidently to the ecological factors can differ ill representatives of the same species if they have been collected from different localities. Further, biomass of ten nematode species is plotted against their stages and found that the geometric growth rate for Biomass varied within species. Five nematode genera: Tylenchorhynchus, Basirolaimus, Helicotylenchus, Rotylenehus and Xiphinema, are selected for determining their relative frequencies (RF), prominence values (PV) and importance values (IV). It is noted that the sequence of arrangement of these genera does not change if arranged according to their ‘RF’ or ‘PV’. But the arrangement is slightly altered if they are arranged according to ‘IV’.
