There are more than 32,000 species of fish on the planet, which makes them the most diverse group of vertebrates. Depending on the species, fish live in freshwater or saltwater environments and breathe by extracting oxygen from the water via gills (although some species can breathe air directly). Fish are found throughout the world’s oceans, rivers and lakes. Fish vary greatly in shapes and sizes, with the largest fish being the massive whale shark at approximately 16 m (52 ft) in length. The average length of a fish is about 15-30 cm (6-12 in), but many species are far smaller. Let’s find out which of the 32,000 species of fish is the smallest in the world.
What is the smallest species of fish?
The smallest species of fish in the world is the Paedocypris progenetica, which is a member of the Paedocypris family of fishes. The Paedocypris progenetica reaches a maximum length of 10.3 mm (0.4 inches), but the smallest mature specimen ever discovered was just 7.9 mm (0.3 inches). The Paedocypris progenetica is native to the Indonesian island of Sumatra. It is commonly found in swamps and slow moving streams on the island. The following is a picture of a number of full grown members of this species :
The second smallest fish is the Schindleria brevipinguis (stout infantfish), which is on the Great Barrier Reef and the Osprey Reef. This species has a maximum length of 8.4 mm (0.33 inches) and the males of this species mature at just 7 mm (0.28 inches).
The third smallest species of fish is the Trimmatom nanus (a species of dwarf Goby). The adult members of this species reach just 10 mm (0.39 inches) in length.
Did you know?
The parasitic males of the species Photocorynus spiniceps (a species of anglerfish) are just 6.2–7.3 millimeters (0.25-0.3 inches) in size. This is smaller than any other species of fish, but the females reach a much larger size of 50.5 millimeters (2 inches).