Feeding Frenzy

With my face behind the camera, and looking the other direction, I did not notice the commotion I had caused. A swirl of colorful motion caught the corner of my eye. I turned to see a horde of butterflyfish attacking a seemingly uninteresting rock face. I watched for a moment before a memory triggered… Of course!

Feeding Frenzy
A mixed school of butterflyfish feeding on the eggs of a Hawaiian Sergeant Abudefduf abdominalis
I knew what to look for… Sure enough, a barred fish darted into the crowd, aggressively driving off a few members of the swarm. But for each fish driven off another two would sweep in behind to peck at the rock face.

It is likely the gang of butterflyfish used my presence as an opening to overwhelm the Sergent. Local lore is full of examples of this behavior. The passage of a larger predatory fish, or a diver, will give the guarding male Sergeant a pause. A slim opening upon which the gang will swarm the eggs and feed. During Sergent breeding season it is not unusual for divers to mention schools of butterflyfish or tangs following them in and around the nesting areas.

Sergeant Eggs
Eggs of the Hawaiian Sergeant (Abudefduf abdominalis) covering a one meter area
With the feeding fish so oblivious to my presence I took advantage of the situation to blaze away with the camera at short range. The were a couple species here that I did not have decent photos of.

I literally have to push my way through the swirling fish to examine the nest. The rock is covered with eggs, an amazing number of little purple dots covering an area of about a meter square. Despite the ongoing feeding frenzy, the nest seems intact, with nearly every bit of the rock covered with the neat little lines of eggs.

Hoover1 makes an interesting observation… “One can only wonder why Sergent eggs are so conspicuous while most damselfish eggs are hardly visible”

1) Hawaiian Reef Fishes, John P. Hoover, Mutual Publishing, 2008

Postcard from the Reef – Gold Lace

Endemic to the Hawaiian Islands the Gold Lace Nudibranch is common, very common. I find these critters nearly every time I poke my head into a cave along the Kohala coast. I was thrilled when I found my first one, but now? Still a pretty animal and worth an exposure or two.

Gold Lace Nudibranch
A Gold Lace Nudibranch (Halgerda terramtuentis) in a cave at 40ft depth, Malae Point

Postcard from the Reef – Fellows Nudibranch

I have seen and photographed these fellows a few times. Endemic to the Central Pacific, the species is commonly seen in dives on the west coast of Hawai’i. The surprise this time was what I found nearby. A flash of bright white is quickly spotted in the beam of my light as I explore the cave. Two spots appeared on the cave roof. The first is the nudibranch, quickly recognized as a Fellows Nudibranch.

I take a couple photos, even though I have seen this species often enough before. I do not immediately notice that the second spot, somewhat hidden in a crevice, is not the same. Upon another look it turns out to be an egg mass, bright white like the slug that laid it. A neat spiral of white eggs against the algae covered rock.

Fellows Nudibranch
A Fellows Nudibranch (Hiatodoris fellowsi) on a cave roof at about 40ft, Malae Point, Kohala, and egg mass was about 6″ away
FFellows Nudibranch Egg Mass
An egg mass from a Fellows Nudibranch (Hiatodoris fellowsi) on a cave roof at about 40ft, Malae Point, Kohala, an adult was about 6″ away

Postcard from the Reef – Camouflage

Curled into the top of a coral head, dressed in nighttime camouflage colors, pretending to be part of the coral. Sitting still just makes it an easy target for the camera…

A Stripebelly Puffer
A Stripebelly Puffer (Arothron hispidus) in nighttime camouflage colors, 35′ depth, Mahukona

Postcard from the Reef – Cushion Star

I have occasionally seen these starfish tucked into the coral by day. When you see just a small part of the animal it is not immediately recognizable as a starfish, just a lump of something that does not match. They emerge at night to feed on the coral itself. Once in the open the five-fold symmetry begins to suggest that you might be looking at a starfish…

Cushion Star
A cushion star (Culcita novaeguineae) on the sand at 40′ depth, Mahukona

Postcard from the Reef – Coral Blenny

Deb spotted this one. I come over the coral head to find her gesticulating at a very large antler coral (Pocillopora eydouxi). These coral are always worth checking out, so many things live amongst the branches. These denizens are fascinating, and frustratingly hard to photograph deep in the branches.

This particular coral had a number of residents… A couple guard crabs and several fish, including this fellow…

Coral Blenny
Spotted Coral Blenny (Exallias brevis) at 15′ depth, Honokohau