The effect, after four years, of a change in biotope on the morphometrics of populations of Xiphinema diversicaudatum (Nematoda: Dorylaimoidea)

Abstract

The published morphometrics of different populations of Xiphinema diversicaudatum (Micoletzky) Thorne are very variable. Such variability may result from operator error, measuring system error, different methods of killing, fixing and mounting specimens or may be natural variation resulting from populations having adapted to survive in different biotopes (Brown, 1981; Brown and Taylor, 1981; Brown and Topham, 1984 and 1985). Cultures of X. diversicaudatum from natural biotopes from different countries and continents were collected at the SCRI and maintained as breeding populations using a standardised method (Brown and Topham, 1984). Nematodes from these cultures were measured upon receipt at SCRI and, after four years, specimens from seven populations were remeasured to assess the effect of a change in biotope on their size and morphology. The results from these studies are presented and discussed here.