Fanged fancy: Images of the carp-like fish, Danionella dracula. Unlike the other 3,700-odd species in its group, the males have tooth-like structures, seen in the scanning electron micrographs image in grey (and also the inset image in pink).
Credit: Britz/NHM
SYDNEY: A new species of tiny fish with jaw structures that look suspiciously like fangs has been discovered by biologists at London's Natural History Museum.
Named Danionella dracula, this new minnow is a close relative of the zebrafish and part of a group of carp-like fishes called cypriniformes, one of the largest orders of fish.
The 17-millimetre-long transluscent fish has evolved a number of unique and unusual characteristics, said the experts, its most obvious, and surprising, being its huge false teeth.
False teeth
"This fish is one of the most extraordinary vertebrates discovered in the last few decades," said Ralf Britz an ichthyologist at the museum.
"The males have something that, on first inspection, looks like a series of large impressive teeth. We therefore named the species Danionella dracula."
Britz discovered the species during an expedition to northern Myanmar, it was described earlier this year in the journal Proceedings of the Royal Society B.
None of the 3,700 species in the cypriniform group have any real teeth in their jaws. Their ancestors lost their jaw teeth about 50 million years ago in the Upper Eocene period. Danionella dracula, however, evolved its own tooth-like structures.
"The males have spectacular jaw modifications that resemble true teeth and protrude through the skin. They represent, however, processes grown from the jaw bones rather than re-evolved jaw teeth," said Britz.
Host of weird traits
The species has a number of other curious traits, too.
The adult also has a "larval-like skeleton" and over 40 bones missing compared to the related zebrafish. The species is also sexually dimorphic, meaning the males differ from the females.
"In addition to the tooth-like processes which are almost absent in females," Britz said, "males have much larger pelvic fins and their anus and genital opening are shifted forward between these fins."
Britz and his co-workers decided to study the exact process by which the Dracula minnow might have miniaturised. Miniaturisation is an evolutionary process that leads to dwarfed, yet sexually mature, organisms.
