The use of high speed plankton samplers is inevitably accompanied by the risk of damage to the specimens in the catch. The techniques used by the Lowestoft laboratory are designed to minimize this damage during collection, fixation and preservation of the catch. To this end a special collecting bag is used in the plankton sampler and the sample is fixed with a new formaldehyde-based fixative marked with eosin dye. This fixative, together with a new observation and preservation fluid used during sorting, results from the recommendation of the SCOR/UNESCO working group on fixation and preservation of zooplankton. Finally the use of polarized light as an aid to counting the myotomes of clupeoid larvae is described and illustrated. This technique is put forward as the only reliable means of differentiating between small or damaged specimens of herring, sprat and pilchard larvae.