Ten centimeters (4 in) of purple fish with six orange stripes, threading through the branches of a coral head at speed and never leaving it. Finding one is easy; photographing one is not.
It hunts the coral's own residents - tiny crustaceans, copepods, and the small parasites that plague reef fish - working the branches methodically all day. In an aquarium the same habit made it famous as the fish that eliminates pyramid snails and bristleworms.
It sleeps inside the coral too, and it does what many wrasses and parrotfish do: secretes a mucus envelope around itself for the night, which masks its scent from anything hunting by smell.
Each coral head holds one dominant fish, and the species is aggressive at its own scale - two males in one colony is not a stable arrangement. Like all wrasses it begins female, and the fish holding the head is one that changed.
The genus. Pseudocheilinus Bleeker 1862 - pseudo- (false). ETYFish
The species. Pseudocheilinus hexataenia (Bleeker 1857) - hexa- (six) + taenia (band or ribbon). ETYFish
- small purple-blue fish with six orange stripes running the length of the body
- green tail and a dark spot at its base
- always inside a coral head, moving constantly through the branches
- length up to 10 cm
Why it's threatened
There are no major threats known to this species, although it is targeted and very popular in the ornamental aquarium fish trade.
Threat classification from the IUCN Red List.
