Ultrastructure of spermatozoa of two species of Myctophidae; Symbolophorus californiensis and Notoscopelus sp

Abstract

The ultrastructure of spermatozoa of two species of Myctophidae, Symbolophorus californiensis and Notoscopelus sp., was examined by scanning and transmission electron microscopes. The spermatozoa were characterized by (1) numerous small spherical mitochondria distributed in close contact with the nuclear membrane covering on S-shaped nucleus of ca 5 μm (L) ×ca 1 μm (W), (2) two centrioles located about 1/3 along the long axis of the nucleus, giving rise to typical biflagellarity, and (3) biflagella ca 47 μm long, each component with an un usual 9+0 axonemal structure. It is suggested that a combination of these three apomorphic characters may be peculiar to Myctophidae.