of the family Acanthuridae
commonly refer to as surgeonfish.
There are 80 species in 6 different genera in this family. All have one
distinguishing characteristic. They have sharp blades at the base of
tails (caudal peduncle) on both sides of their bodies that are used in
self-defense. Seventeen of the
species are unicornfish.
Here we will
elaborating on the unicorn tang. They are endemic to the Indo-Pacific
from Indonesia and Christmas Island westward to the Andaman
south to eastern
coast of Africa and
east to the Hawaiian
to Like Us!
A significant populace of
these creatures exists around the
shores of the Hawaiian
prized by ancient Hawaiians both as a source of food and for their
tough skins were used in the construction of drum heads. This species
considered aggressive to human intrusion. However tourist diving off
the Hawaiian Islands should avoid chasing or
corning these creatures. Sports
fishermen should use extreme caution when removing them from hooks or
receive their names from the horn-like projection at the top of their
This horn begins to develop in early adulthood.
These unicorn horns
longer as the fish continues to mature. The function of these horns is
They have yet to be observed using these spinal adaptations as a means
unmistakable defensive mechanism employed by all members of
scale structures at the base of their tail. These structures are
sharp. When threatened, this family will thrash their tail about hoping
dissuade their aggressors from further attempts at predation. These
slice into flesh as efficiently as a surgeon’s scalpel. In
addition to self-defense,
surgeonfish use their blades to ward off intruders from their feeding
Most surgeonfish have just one set of retractable blades located in a
both side of their tail. Unicorn tangs have two fixed blades on either
These double blades are the defining characteristic of the genus Naso.
distinguishing feature helps to identify the fish’s genome.
Not all unicornfish
develop the horn for which they are commonly named.
have the flat, teardrop shaped bodies common to most tangs. They are
bluish-grey in color and have long, flowing lyre shaped caudal fins.
sold by the aquarium industry under the pseudonyms Naso unicornfish and
tangs are among the largest species made available by the aquarium
They can grow to a maximum adult length of 27 inches. This is
why you will seldom see one in a home
aquarium. They require a minimum tank size of 250 gallons and are best
for large show tanks. Because of their
ties to one of the most elegant of all mythological creatures, they are
additions to public aquaria.
tangs are herbivores. In nature their diet consists
algae. Since they are unlikely candidates for home
aquariums, there seems little point in covering dietary conditioning in
the unique aspects of surgeonfish is their communal mating habits.
spawning seasons they will congregate in large groups.
release eggs and sperm into the water for fertilization. There is no
courtship or coupling found among surgeonfish in the wild.