Many of the Hawaiian fish species only live in Hawaii because the island chain is so isolated that many fish species evolved here and nowhere else in the Pacific Ocean. For a fish to get all the way to Hawaii its eggs must be able to float in currents from as far away as Tahiti or Guam so over millions of years Hawaii has a lot of beautiful reef fish but not as many as most other Pacific Islands.
The Orangespine Unicornfish is a very successful fish species occurring all around the world from Hawaii all the way to Japan and Australia. Here in Hawaii it was given the Hawaiian name umauma lei many years ago but in other parts of the world it is called the lipstick tang or barcheek. It is such a comical looking fish that each culture has its favorite name for it but what makes this 18 inch long fish so successful worldwide.
The Orangespine Unicornfish is a type of surgeonfish. Surgeonfish get their name from the sharp scalpel-like spines on each side of the base of their tail. These are called a caudal peduncle and they are razor sharp just like a surgeon’s scalpel! On umauma lei the spines are bright orange as a warning to stay away. It is hard for a predator to eat one of these fish because they have very thick skin and are super strong swimmers and if grabbed they will flip their tail at you and deliver a very deep cut!
These large unicornfish do not have the horn on their head like other species do but they are very good to eat. The fish feed on algae so you cannot catch them with a fishing pole but they are often speared or caught in a throw net. I know many fishermen that have tried to catch them but only once as they can get tangled in the net and ruin it before you can untangle them without getting cut by their slashing spines. Spearfishermen sometimes try to spear one and then wish they had not done so as they are extremely difficult to remove from the spear without getting cut up. This may be one good reason why this fish species has thrived in more marine environments then almost any other type of reef fish.
The best way to see umauma lei up close without any danger of getting cut is to visit one at night. They come into shallow lagoons and close to shore to sleep in cracks in the reef where they often have their head in a crack with their shark orange spines exposed. Their bright colors in the dive lights make them easy to find.
You can see the Orangespine Unicornfish in action in my video The Worlds Guide To Hawaiian Reef Fish up on my marine science educational web page at www.underwater2web and also follow my weekly marine life Instagram post at terry.lilley.
Terry Lilley is a marine biologist living in Hanalei Kauai and co-founder of Reef Guardians Hawaii, a nonprofit on a mission to provide education and resources to protect the coral reef. To donate to Reef Guardians Hawaii go to www.reefguardianshawaii.org.