It’s not unusual to see a variety of fish performing the same maneuver as this chub. I think what it’s doing is rubbing off parasites that attach themselves to fish. They seem to like this particular rock, possibly because of its rounded top and just the right amount of abrasiveness.
The Bicolor Chub is one of several chubs here, but the only one endemic to Hawaii. While it has a lot of similarities to the Gray Chub, the two-tone coloring makes it easy to identify. Some Bicolor Chubs are dark at the back and light at the front. This one also has the dark top to its head and face. Some of them also have dark backs so that the only light part is the belly area.
Conditions have been terrible for snorkeling lately. There’s been one swell after another barreling in from the northwest, which is good news for surfers, but which churns up the water and makes it hard to see anything.
Despite this, there can be clear patches and it was passing through one of these that I saw this school of chubs swimming by me, nicely illuminated by the sunlight.
A variety of fish swim in the surge over a shallow part of the reef. The yellow chub is an unusual color variant of the gray chubs swimming with it.
Fish swim just below the surface in surging water. The big fish are highfin chubs and the smaller fish are acute halfbeaks.
A variety of reef fish – including yellow tang, goldring surgeonfish, whitebar surgeonfish, brassy chub, and ember parrotfish – forage on a shallow rocky shelf.
The yellow chub in this photo is actually a gray chub, but a few individuals, such as this one, can be yellow, white, or multicolored. This one is something of a regular at one spot on the North Kohala coast.
The orangespine unicornfish is seen in many places along the coast and always has a grumpy look. In this case, it looks like it’s upset that the chub has swum into its territory.
On a recent swim I saw these two fish passing by. They looked like chubs, but not ones I’d seen before. I snapped a quick photo, not expecting it to be great, but hoping it would help me identify the fish. I need not have worried.
After they passed, they made a series of approaches and retreats. They appeared as curious about me as I was about them, which is something of a characteristic of chubs. Eventually, they moved away and I carried on, catching up to two others I had been swimming with. I asked them if they’d seen these fish and they said no.
I was describing what they looked like when the two of them showed up again. Once more they looped around, checking out these new people before finally heading south, not to be seen again.
When I got home it was easy to identify them as rainbow chubs, also known as blue-stripe chubs, with their distinctive blue markings. What was interesting is that their home is the Eastern Pacific, from Ecuador north to California. But some can get carried over to the Central and Western Pacific. As such, they’re rare in Hawaii, so this is one of those fish I might never see again. A matter of being in the right place at the right time.
In my attempts to identify what I see in the water, I use John P. Hoover’s book The Ultimate Guide to Hawaiian Reef Fishes, Sea Turtles, Dolphins, Whales, and Seals. His website is hawaiisfishes.com.
Graham's Island 