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Also think so. Plenty of fish are vibrant blue, the blue whale is grayish blue but still blue.

Also plenty of birds are blue are they not?

And I totally forgot about butterflies and other insects as well

One in two million lobsters is blue https://allthatsinteresting.com/blue-lobster

Only cartoon fish are blue.

There are two interesting cases of blue fish in my home state.

1. The Beardslee Trout, which exists only in a single lake in the world: https://en.wikipedia.org/wiki/Beardslee_trout. Most photos online of these fish, including the Wikipedia thumbnail, are not representative of the stunning color of these fish in person, and are most likely not Beardslees at all. The lake itself looks like blue gatorade, and the fish have obviously adapted accordingly.

2. Lingcod, a fraction of which are a crazy alien blue color not only outside but throughout the flesh. https://oregonmarinereserves.com/2021/08/31/lingcod/. This phenomenon applies to a handful of species, but lingcod is the most well-known.

Blue tang?