Monogenetic Trematodes of Westhampton Lake Fishes. I. Two New Forms

This paper is the first of a series from a recent study on monogenetic trematodes of Westhampton Lake** fishes. It comprises descriptions of two new species. Teclhniques of previous workers (Mizelle, 1938; Mizelle and Cronin, 1943) were extensively employed in preparing the worms for study and sevezral new methods were devised and utilized. A new technique of recovery involved immersion of branchial material in a small Petri dish of tap water in which a few crystals of Chloretone (Parke-Davis) had been dissolved. The gills were left therein until the worms were relaxed, then the parasites were micropipetted onto slides which had been prepared for affixing. It is possible that this method damrages the delicate tissues of the flukes less than does the freezing technique, but further experimentation must be done before any definite conclusions can be made. Haupt's adhesive (see Johansen, 1940) proved to be the most effective affixing agent. Practically all of the parasites remained on the slide when they had been properly affixed. One can shorten the affixing process by disp nising with the separate application of formalin in the hardening process by preserving the worms in 3-4 per cent formalin and pipetting them directly from the fixative onto the coated slide. After adhesion the non-formalized worms were fixed in Carnoy's solution or 70 per cent alcohol. Some of the worms were mounted unstained on slides using the glycerinejelly technique as described by Mizelle and Cronin (1943). Other unstained parasites were upgraded from 70 per cent through 100 per cent alcohol into Euparal. This is a new technique for freshwater Monogenea and is superior to the glycerine-jelly method in that it produces a permanent mount and does not obscure the chitinous parts which are of critical taxonomic importance. Some specimens were stained, and while results were not uniform and often unsatisfactory the process often revealed structures that were not otherwise apparent. Differential staining is very helpful and it seems probable that new and better staining techniques could be perfected. Observations wer;e made also on living material. Measurements and drawings were made with th-e aid of a calibrated ocular micrometer and camera lucida. All measurements were made across the arc described by curved structures. Cotypes of related forms were studied for comparison.