A
Bicolour Cleaner Wrasse.
The anterior
part of adults is mostly blackish-blue, while
the anterior part of its body is mostly yellow,
with some blackish margins around the fins and
tail.
These fish are best-known for cleaning larger
fish, such as this Yellowtail Coris Wrasse,
which they
clean up, benefiting from this by feeding on anything that they remove
from them.