The fine structure of the spermatozoa of two species of Rhacophorus ( arboreus, schlegelii) : I. Phase-contrast microscope, scanning electron microscope, and cytochemical observations of the head piece

Abstract

Green tree frogs, Rhacophorus arboreus and Rhacophorus schlegelii, living on the main island of Japan have spermatozoa in the form of a counterclockwise corkscrew composed of about 20 coils arranged in the shape of a cone. A head piece coiled loosely and tightly 5–6 times each. It was composed of two subcoils, one outside and the other inside. The outside subcoils composed the nuclear head, and the inside coils the acrosome. Following the head piece, a middle piece which had a mitochondrial sheath coiled 1 1 2 times. A tail piece which followed the middle piece coiled 3–10 times irregularly in 5–6 μm width with a 20- to 30-μm straight tail in length. There was a crystalline composed of 500–600 microtubules which surrounded a pair of cilial structures in the tail piece. The tannic acid-aldehyde-osmium tetroxide fixation method produced excellent electron density and good electron conductivity for scanning electron microscope observations.