Abstract
The morphology and intramembranous particle (IMP) distribution of spermatozoa were investigated in four species of cyprinid fishes, Gnathopogon elongatus elongatus, Pseudogobio esocinus, Acheilognathus lanceolatus and Puntius tetrazona. In particular, observation of IMP distribution was conducted as an aspect of comparative spermatology in cyprinid fishes and was continued from a previous paper (Ohta et al., 1994 (8)). Although the fundamental structures of the spermatozoa were similar among the four species, the distribution of IMPs varied. Hexagonal (or parallelogrammic) arrays of IMPs on the sperm head membranes were present in G. elongatus elongatus, A. lanceolatus and P. tetrazona, but not in P. esocinus. The hexagonal arrays have now been confirmed to be present in twelve of the thirteen species of cyprinid fishes examined so far.
