The testes of Ance34Eb-2/Ance34Eb-1 males are extremely variable in appearance. Most are small with few elongated spermatids, no individualised sperm, and degeneration of variable extent. Ance34Eb-1/Df(2L)Adh-nBR55 mutant testes are more consistent in appearance, they are full length but there is no evidence spermatid individualisation. Very few individualisation complexes are observed, and these are usually associated with spermatid nuclei. Mutant spermatid nuclei are often scattered along the cyst, and many nuclei had spherical instead of the needle shaped morphology. The cysts lack overall organisation and contain abnormal lobed mitochondrial derivatives. The major derivatives are variable in morphology, often distended and appearing dumb-bell shaped in cross section.. The minor derivative are larger than wild-type, though usually smaller than the major derivatives in the same cyst, and are sometimes misshapen.