Arc-eye Hawkfishes come in two color variations. The top photo shows one that is reddish tan with a white stripe on the side. The bottom photo shows a fish that is a darker brown with no white stripe.
According to my fish book, John P. Hoover’s The Ultimate Guide to Hawaiian Reef Fishes, Sea Turtles, Dolphins, Whales, and Seals, the white stripe coloring is most common in deeper water where the coral is spaced farther apart. In shallower water, where the coral colonies are closer together, the darker coloring predominates. However, both these photos were taken in shallow water so it’s not an either/or situation.
It’s not unusual to see this kind of gang activity while snorkeling, and what they’re doing is hunting. Their prey is small fish that take sanctuary in coral heads and among the rocks.
This bunch of hunters is dominated by Blue Goatfishes, easily identified by their blue bodies and yellow saddle at the base of the tail. There’s also a Bluefin Trevally and Pacific Trumpetfish toward the bottom of the photo and, near the top of the photo, a Peacock Grouper with a Whitemouth Moray Eel curling below it.
Eels are popular members of these hunting parties because they can wriggle into the smallest spaces, flushing out prey. The goatfishes perform similar work using long, white barbels below the chin to probe small spaces in the hopes of disturbing a meal. Other fish tag along hoping to be beneficiaries of this work by being the first to snag any victims that get flushed out.
This week’s Sunday Stills color challenge theme is ‘Teal or Aqua.’ See more responses here. I’m going underwater for a selection of aquatic aquas.
The top photo shows what happens when divers have too much time on their hands.
Next, we have some Square-spot Goatfishes and a few Orangeband Surgeonfishes meandering over a patch of sand. Then a Bullethead Parrotfish displaying a variety of colors. And a shoal of Hawaiian Silversides going hither and yon over a rocky bottom.
Finally, a couple of Spinner Dolphin photos, where they swam below me over an aqua background.
A Pacific Trumpetfish drifts in the water as a couple of Yellow Tangs pass by. Trumpetfishes often hang vertically, head down waiting to snag a meal. They also change color and markings to blend in with other fish, hoping to sneak up on prey.
Trumpetfishes looks easy to spot, but they propel themselves with dorsal and anal fins set far back on the body where they’re not seen by potential prey and, from the front, which is where its prey is, they’re very hard to see.
The top photo shows a Flowery Flounder resting on a patch of sandy sea floor. These fish blend in so well they’re almost impossible to spot. The trick is to spot them on the move (second photo). In motion, they’re quite distinctive with their undulating movement, especially if the pectoral fin is raised as in this photo.
The third photo shows the fish just as it landed on the sand to begin its very fast process of blending in.