World’s Smallest Fish, Paedocypris progenetica
A new species of fish called Paedocypris progenetica, has been discovered in highly acidic peat swamps on the Indonesian island of Sumatra. The new species belongs to the carp family and is possibly the world’s smallest vertebrate animal with females maturing at 7.9 mm.
‘This is one of the strangest fish that I’ve seen in my whole career’, said Ralf Britz, zoologist at the Natural History Museum in London who helped analyze the skeleton and pelvic fin structure of the fish. ‘It’s tiny, it lives in acid and it has these bizarre grasping fins. I hope we’ll have time to find out more about them before their habitat disappears completely.’
The new fish was discovered by fish experts Maurice Kottelat (from Switzerland) and Tan Heok Hui from the Raffles Museum of Biodiversity Research in Singapore, while working with their colleagues from Indonesia and with Kai-Erik Witte from the Max Planck Institute in Germany.
P. progenetica is so tiny that researchers initially thought they were baby fish until someone noticed the females were carrying eggs. The tiny, see-through fish also has a reduced head skeleton, which leaves the brain unprotected by bone. They live in dark tea-colored waters with an acidity of pH3, which is at least 100 times more acidic than rainwater. These swamps were once thought to harbour very few animals, but recent research has revealed that they are highly diverse and home to many species that occur nowhere else. The peat swamps were damaged by large forest fires in 1997 and are threatened by logging, urbanization and agriculture. Several populations of Paedocypris have already been lost.
Although announcement of this new species claims it to be the world’s smallest fish, the Australian Museum Fish Site has a fun article that tells of 2 other contenders to the title of ‘World’s Smallest Fish’.
Hungry for more information? Check out budak’s Blog with lots more pictures and discussion. Also, the researchers’ report was published in the British journal, Proceedings of the Royal Society B. You can read the abstract but for full access you’ll need to check it out from a library that subscribes to the journal: Paedocypris, a new genus of Southeast Asian cyprinid fish with a remarkable sexual dimorphism, comprises the world’s smallest vertebrate.
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cypriniformes
Family: Cyprinidae