The royal blue tang is a crucial species of coral fish. Already popular marine aquarium addition, it was even further popularized by the animated movie Finding Nemo, where one of the main characters was a royal blue tang named Dory. Currently, every individual held in an aquarium is captured in the wild, but scientists give hope that it may soon be a capture-bred species.
It is the only member of the genus Paracanthurus of the family Acanthuridae.
The family groups tangs, unicornfish, and surgeonfish.
Due to its common name, blue tang, it tends to get confused with the Atlantic blue tang.
They are, however, easily distinguishable, since the royal blue tangs have bright yellow tails.
It is common in the tropical reefs of the Indo-Pacific.
It is royal blue, with a yellow tail, and a dark blue or black palette-like pattern on its body.
Juveniles are yellow, with light-blue edging on dorsal fins.
When the royal blue tang gets stressed, it can change its color to dark purple.
Males are larger than females.
They typically measure 25-30 centimeters and weigh up to 600 grams.
It possesses a razor-sharp spine sticking out near its tail.
It contains a toxin, capable of causing severe pain.
They are omnivorous.
Primarily, they feed on plankton but will nibble on algae. In fact, they are crucial in keeping the reef healthy, since preventing algae from overgrowing and choking corals.
Juveniles feed on plankton only.
The royal blue tang reaches sexual maturity at 9 - 12 months of age.
When it is time to breed, males and females congregate.
The fertilization is external: males expel the sperm, and females the eggs.
Fertilized eggs, that measure up to 0,8 millimeters, hatch within 24 to 26 hours.
Juveniles are called larvae and occupy the coral habitat until they mature. Maturity is not measured with age, but with size–females are considered mature when measuring 13 centimeters, and males when measuring 11 centimeters.
Royal blue tang cannot be bred in captivity. Yet.
A group of scientists managed to breed a royal blue tang in 2016, so hopefully captive-bred may be available in some time.
They live an average of 30 years in the wild.
Their average lifespan ranges from 8 to 20 years in captivity.
It is one of the most popular marine aquarium fish.
They have very sensitive skin, however, and are prone to diseases.
Eating a royal blue tang will result in ciguatera fish poisoning.
Every species of reef fish carries ciguatoxin and maitotoxin from the consumption of small organisms. One in 1,000 cases of poisoning will end up in death.
They tend to swim in large schools, usually accompanied by other species from the family Acanthuridae.
They are very sociable, so it is advised to keep at least a pair of blue tongs together. However, males tend to be aggressive toward each other.
They are listed as the least concern by the IUCN.
There are very common, even used as baitfish.
Scientists were concerned after the release of the animated movie “Finding Dory” (the sequel to the very popular “Finding Nemo”), that the demand for royal blue tangs would drastically increase, as was the case with clownfish after the 2003 movie “Finding Nemo.” Fortunately, that did not repeat.