eusperm

English

eusperm (plural eusperm)

(zoology) In species that exhibit sperm heteromorphism, fertile sperm.
- 2009, Daniel H. Shain, Annelids in Modern Biology, page 322:
  […] the eusperm (i.e. the fertilizing spermatozoa) are filamentous cells with a tapered, tubular, terminal acrosome, an extremely elongate nucleus, a cylindrical sometimes spiral midpiece formed by two to six radially adpressed mitochondria […]