Rhinobrycon negrensis (Fig. 15 A-E)

In the spermatozoon of Rhinobrycon negrensis, the spherical nucleus measures approximately 1.5 µ m in diameter. The surrounding strip of cytoplasm has no organelles (Fig. 15A). Nuclear rotation toward the flagellar axis was about 50 degrees (Fig. 15 A-B). Large vesicles are found laterally to the nucleus (Fig. 15 B-C). The midpiece has a rhomboid shape, measures about 1.1 µ m in length and contains some mitochondria (Fig. 15 A-C). The endomembrane system is composed of a few large vesicles (Fig. 15 B-E).