Dracula fish

Danionella dracula
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Cypriniformes
Family:	Cyprinidae
Genus:	Danionella
Species:	D. dracula
Binomial name
Danionella dracula Britz, Conway & Rüber, 2009

The dracula fish, Danionella dracula, is a species of tropical danionin fish from the cyprinid family. It is a freshwater fish indigenous to Burma. A close relative is Brachydanio rerio, the zebrafish of aquariums. It is named dracula after its unusual "fangs": male dracula fish have protruding tooth-like bones stemming from their jawbones. Males have been observed using their fangs to spar against other males.^[1][2]

Identified in April 2007^[3] from specimens shipped to the United Kingdom in a consignment of aquarium fish, the dracula fish has so far only been found in the wild in a small stream at Sha Du Zup between Mogaung and Tanai in northern Burma.^[2] It is a colourless miniature species and grows to a maximum size of around 17 millimetres (0.67 in).^[4] The fish has an elongate body with a large head and eyes. Dracula fish lack scales and the upper body is dominated by the jaws on large males. Much of the fish's structure is cartilaginous, it has 44 fewer bones than the zebrafish, and thus it is translucent and appears similar to larval forms.^[1][2] The natural diet of the dracula fish is unknown but in captivity it eats shrimp larvae, small nematodes and fish flakes. Close relatives of the fish feed upon small crustaceans and invertebrates.^[5]

The dracula fish is unusual in that its ancestors lost their true teeth around 50 million years ago, but re-evolved its bone fangs as a replacement around 30 million years ago.^[2] The species is sexually dimorphic in that the female does not have such prominent bone fangs. It becomes sexually mature while its body is still not fully developed; scientists speculate that this may happen because younger fish were more successful reproductively.^[2] Ichthyologist Dr Ralf Britz, who named the fish after Bram Stoker's character Count Dracula, stated that the dracula fish "is one of the most extraordinary vertebrates discovered in the last few decades."^[1][4]

References

1. ^ ^{a b c} Black, Richard (2009-03-11). 'Dracula' fish shows baby teeth. BBC News. Retrieved on 2009-03-11.
2. ^ ^{a b c d e} Ralf Britz, Kevin W. Conway, Lukas Rüber. (2009-03-06). Spectacular morphological novelty in a miniature cyprinid fish, Danionella dracula n. sp.. The Royal Society. Retrieved on 2009-03-11.
3. ^ Tiny fish developed its own set of dracula fangs. The Times (2009-03-11). Retrieved on 2009-04-30.
4. ^ ^{a b} Devlin, Kate (2009-03-11). New 'dracula' fish discovered. The Daily Telegraph. Retrieved on 2009-03-11.
5. ^ Jaggard, Victoria (2009-03-11). Photo In The News: New "Dracula" Fish Discovered. National Geographic. Retrieved on 2009-03-12.