THERE’S sperm, and then there’s super sperm – many times longer than the minute crustaceans that produce them. Now it seems that ostracods, or seed shrimp, have been producing giant sperm for at least 100 million years.
Renate Matzke-Karasz at Ludwig Maximilian University in Munich, Germany, and colleagues produced 3D images of 100-million-year-old fossil ostracods by firing X-rays through them. The images show two large sperm pumps called Zenker’s organs, resembling those found in living giant-sperm-producing ostracods (Science, DOI: 10.1126/science.1173898).
Such a long history of giant sperm points to intense sexual competition between males, says Matzke-Karasz.
