Postcard from the Reef – Page 13

Postcard from the Reef – Night Colors

Many reef fish change color for the night. Many lose their bright daytime colors to become rather drab, most likely in order to evade the predators who scour the reef at night. Moray eels, reef sharks, and more are on the hunt, looking for the fish hiding in the nooks and crannies of the reef. For the diver a nighttime reef it totally different, the clouds of fish hovering over the coral are gone. Here and there a few fish are visible, the color seemingly drained from them as they wait out the night.

Longnose Butterflyfish — A longnose butterflyfish (Forcipiger flavissimus) in nighttime coloration during a night dive at Puakō

Postcard from the Reef – Regeneration

You may know that a starfish can regenerate a lost limb. Seeing it in process? More extreme… A single limb regrowing the rest of the body? It is a bit surprising to see such a bold example of regeneration in process.

The limb may have been parted by injury. Another possibility here is reproduction. Some species reproduce by simply detaching an arm in a process called autotomy. The detached arm becomes a new individual. An impressive capability indeed.

Regenerating Linckia — A green linckia starfish (Linckia guildingi) in the process of regenerating from a single arm

Postcard from the Reef – Too Close

It was a reasonably big eel, not the largest I have seen, but large. I stopped to take a couple pictures, even though I have plenty of photos of yellow-margin moray. The yellows are among the friendlier members of the morays, known to play with divers. Undulated morays, on the other hand, are downright nasty, biting at anything that intrudes on their space.

This is too close.

When this fellow comes out to inspect the camera, it is my turn to pull back a bit. True, it is the camera front and foremost, most likely to get nipped. Still, I give the eel a fair amount of respect, a “friendly” eel still possess a substantial bite.

Postcard from the Reef – Sleeping Parrotfish

A number of parrotfish species can secrete an odd mucus cocoon in which the fish will sleep through the night. Divers will often find these fish at night, enveloped in a transparent balloon. The discarded cocoon makes an odd sight rolling around the reef the next day.

Even within the same species some fish will use this technique, some will not. It is not known how this behavior is useful to the fish. This very large bullethead parrotfish is sleeping without aid of a cocoon…

Bullethead Parrotfish — A large bullethead parrotfish (Chlorurus spilurus) sleeps in the coral

Postcard from the Reef – Honeycomb Coral

It is worth a moment, even in the limited time of a dive, to stop and look close at the coral itself. Never mind the psychedelic fish, the coral is what makes a reef. Untold billions of small polyps, each a separate animal, cooperate to build the largest natural structures in the world.

Some corals are easier to examine closely. Honeycomb coral has corallites much larger than most, easier to get a good look without magnification. Getting your mask close allows you to appreciate each little animal, part of the larger colony.

Looking for Lavern

I dove with the usual crew the day before, but I did not go out with them Sunday. Now I am wonder if I should have. They came back with a fish tale and the video to prove it…

Lavern is a well known fixture around the entrance to Honokohau Harbor. She is big and easily identified through the messed up dorsal fin. She has not eaten any divers… yet.

Needlefish in the Surf

As I came clear of the sea cave I knew I was right under the surf crashing on the rocks. Not truly dangerous, we would not have been out in a really big swell, bad enough if I had decided to go right into it. Kicking out a bit further I surfaced, into a swarm of needlefish hunting along the edge of the foamy water. These little predators appeared to be taking advantage of the reduced visibility and noise of the waves and bubbles to hunt. As they darted through the intense blue water, I attempted to take a few photos. First, get the camera out of macro, turn off the strobe, daylight color balance, anything else?

Category: Postcard from the Reef