Deformed sperm cell. Coloured scanning electron micrograph (SEM) of double-tailed sperm cell, or spermatozoon. A sperm cell's motility may be seriously affected by having multiple heavy tails. All men have a few deformed sperm in their ejaculate, but an overabundance of them can mean that the man is infertile. Also, as men age the number of abnormal sperm cells they produce increases. Magnification: x8600 when printed at 10 centimetres wide.