Toby fish are small puffer-fish, and each species occupies a different habitat in the sea.
The very common spotted toby you see while snorkeling is active during the day in shallow water close to shore. The ambon toby is blue and green, and they like to hang out in caves, and also are active at night when the spotted toby sleeps.
Pu‘u olai is a small, 5-inch-long puffer-fish that is white and brown, and it lives in deeper water, from about 30 feet deep to 60 feet deep, and feeds out on the reef and sand during the day. You more often see these tobys in pairs, and they are very friendly towards divers. Their Hawaiian name means “cinder cone” or “lava flow” because the brown bands on their white back look like a lava flow out on a white beach!
When you are diving and you find a pair of crowned tobys, you don’t need to chase them to get a good look. They are quite territorial, and if you remain still they will come right up to you and pose for their picture. They are a super fun fish to watch, as they look like two little helicopters flying together, and they can hover or go backward at any time. They have pointed noses with sharp grinding plates, and they feed on small animals. They even have a very unique way of finding food out on the sand.
Because they are a puffer-fish, they can fill up with water and look like a little balloon, but they can also gulp down water and shoot it out of their mouth to blow sand off the sea floor, exposing little crabs that live under the sand, on which they gobble down.
Pu‘u olai like all puffer-fish have a very toxic poison in their skin and fat layers called a tetrodotoxin, and this neurotoxin can kill large fish and also humans if they try to eat the toby. Studies have shown that only 1 millimeter of tetrodotoxin can kill a human within 15 minutes! Some cultures around the world dry out these fish and use them as a poison. In small amounts tetrodotoxin can give people a “drugged high” type feeling, and is sometimes used for pain relief, much like an opiate drug.
I have never seen another fish try to eat pu‘u olai, but I have seen octopus catch them at night and try to eat them! Maybe the octopus is immune to the neurotoxin or knows how to avoid it when eating the parts of the toby that are toxin-free.
One animal we do know that loves to harass the crowned toby are dolphins. Bottlenose dolphins have been observed catching a pu‘u olai in their mouth and then passing it along to other dolphins. It looks like they are playing some type of game, and after a while the dolphins start acting goofy as if they were drunk! They may be getting a drugged effect by absorbing a small amount of the neurotoxin. Dolphins are very intelligent, and just maybe they like to party with their buddies from time to time by playing “toxic toby tag.” You can see pu‘u olai in action at underwater2web.com in my movie “The World’s Guide To Hawaiian Reef Fish,” and also in my documentary movie about the marine life at Sharks Cove O‘ahu that is posted up on my YouTube channel at underwater2web. All of my movies are made for children to watch, and can be enjoyed by the whole family and classroom.
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Terry Lilley is a marine biologist living in Hanalei and co-founder of Reef Guardians Hawai‘i, 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.
