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.