Effect of different concentrations of formalin and T.A.F. on the fixation of Longidorus elongatus

Abstract

Different types of mounting media can significantly affect the measurements of nematodes (Curran and Hominick, 1981). No comparable investigations have been made on the effect of different concentrations of the same fixative on nematode measurements although recommended levels of these chemicals can vary e.g. between 5-10% formalin (2-4% formaldehyde) (Hooper, 1970). Formaldehyde based fixatives are used extensively in nematology (Hooper, 1970) but recent reports have cast doubts on the safety of some of these chemicals (Davies, 1974, Anon, 1981). This paper reports the results of observations on the use of reduced concentrations of formaldehyde (HCHO) and T.A.F. (triethanolamine formalin) (Courtney et al., 1955) and their effect on the morphometric characters used to identify nematodes.