Most fertile fish

Found in temperate and tropical waters worldwide, the ocean sunfish (Mola mola) is the most fertile of all living animals. The ovaries of one female contained 300 million eggs, each measuring about 1.27 mm (1/20 in) in diameter.

Some scientists now think that the record specimen could have been a bump-head sunfish (Mola alexandrini), rather than an ocean sunfish (Mola mola), but when the egg count was conducted in the 1920s, the individual was not identified morphologically, so we cannot be certain.