Histochemical Studies of the Cestode Hydatigera taeniaeformis Batsch, 1786

Abstract

The histochemical distribution of glycogen, lipid, mucosubstance, acid phosphatase, alkaline phosphatase, and Feulgen-positive material has been determined in larval and adult Hydatigera taeniaeformis. The distribution of glycogen in adult and larval worms is similar to that reported for other cestodes. The cuticle contains none, or only very little. The subcuticular cells are generally negative, but the cortical parenchyma just below them shows heavy concentrations of glycogen. The medullary parenchyma contains large concentrations of glycogen particularly around the uterus. The parenchymal glycogen is concentrated into small granules. In the larvae, the amount of parenchymal glycogen decreases toward the posterior end of the worm. In addition, the granules become smaller and much of the material around the parenchymal musculature is absent in the region of the pseudostrobila. The cuticle and subcuticular cells of adults and larvae contain PAS-positive mucosubstances. There appears to be a stronger PAS reaction in the outermost portions of the adult cuticle. The larval cuticle gave a uniformly intense reaction. Metachromasia with toluidine blue was not obtained, but orthochromatic staining with toluidine blue was distinct in the adult cuticle at pH levels as low as 3.5, and in the larval cuticle and adult and larval subcuticular cells at pH levels as low as pH 2.6. The adult and larval cuticle and subcuticular cells contain Sudan-positive lipid material. The parenchyma as well contains lipid, with heavier concentrations around the excretory canals and in the vicinity of the uterine branches in the adult. Acid phosphatase activity was found in highest concentrations in the cuticle. The subcuticular cells show faint activity while the parenchyma is negative or only slightly positive. Alkaline phosphatase activity was found with the greatest intensity in the cuticle and subcuticular cells. A faint reaction was found around the parenchymal musculature. The nuclei of both larvae and adults are Feulgen positive. Some complications with this technique were not resolved, particularly in regard to optimum hydrolysis time. This varied from 12 min to 1 hr depending upon the preparation and upon the nuclei in question.