Caption

Fruitfly penis. Coloured scanning electron micrograph (SEM) of a male fruitfly (Drosophila buskii) penis and lower abdomen. Female fruitflies will mate with several males before laying eggs. Males are able to displace the previous male's sperm to ensure that only his sperm will fertilise her eggs. The portion of the male reproductive organs involved in penetration is known as the aedeagus. Fruit flies are attracted to rotting fruit, which they eat and lay eggs in. They are also commonly used in genetic research. Magnification: x240 when printed at 10cm wide.