Category Archives: Marine Invertebrates

Kawaihae dirt storm

Kawaihae dirt storm

The winds were blowing here last week, 30+ mph on a consistent basis. But one afternoon the winds picked up even more and triggered dirt storms off the hills above Kawaihae.

The wind whistled down the slope from Kohala Mountain and dry dirt was gathered up, whirled around, and blasted down the slope toward the ocean. This happened for an hour or so. Sometimes, white sand from the beach in Kawaihae harbor was similarly stirred up.

The unfortunate aspect of this display was that it visibly demonstrated the problems with erosion when the ground is dry. If it’s not the wind, then any rainfall washes the soil down gullies and into the ocean. All this dirt being deposited in the relatively shallow waters off the coast degrades the water quality and can have a seriously adverse effect on corals in the area.

Dwarf moray eel

Dwarf Moray eel

I was watching some fish in fairly shallow water when, below them, I noticed this eel tucked away in a groove in the rock. It looked different to anything I’d seen before, but often the young of a species can look very different to the adults. However, a browse through my fish book showed it’s a dwarf moray eel, which doesn’t grow to more than 12 inches long. The clinching feature, which can be seen in this photo, is the dark bar through its eye.

Dwarf morays are fairly common in Hawaii, but because of their size and their reclusive nature they’re not often seen. This was as far as this eel emerged from of its hiding place so I was happy to get this shot.

I think the pinkish pincushion next to it is a rock-boring urchin, which gets its name from the fact that it can bore into solid rock by scraping with its spines and teeth. A second of these urchins can be seen in the little recess below the main one.

Three green turtles and a passenger

Three green turtles

It’s not unusual to see green turtles hauled out on shore. Sandy beaches are prime resting spots, but these three chose this rocky bay, only a few hundred yards from some of the best beaches on the island. Perhaps they valued quiet over easy access.

The middle one of the three had gained a passenger that I didn’t notice until I processed the photos, an a’ama crab, making the most of its excellent vantage point.

Green turtle and A'ama crab

A flowery flounder and lobe coral

Flowery Flounder and lobe coral

A small flowery flounder passes over what I think are patches of lobe coral. Those two bumps casting shadows on the top of the fish are the flounder’s eyes, which sit on the end of small stalks. As you can see in the photo, the two eyes are pointing in different directions. This isn’t a case of wandering eyes; they work independently.

However, flounders, like other flatfish, do indeed have the most remarkable wandering eyes. Flatfish start out looking like regular fish, with one eye on each side of the head. As they transition from the larval to juvenile stage, one of the eyes migrates over the head to join the other one on what ends up being the top side of the fish.

The eyes migrate to different places, depending on the kind of flatfish. Some are left-eyed and some right-eyed, which refers to the eyes’ relationship to the mouth. Flowery flounders are left-eyed flatfish, the eyes being to the left of the mouth when seen from head on.

There are pros and cons to photographing flounders and other fish that rely on camouflage for protection. On the plus side, once they settle, they tend not to move so it makes it easier to get a photo. On the downside, because they blend in so well, it’s not easy to get a photo where the fish is clear. The best hope is to see one on the move, as I did with this one, not only to get a photo, but also to enjoy their elegant motion as they ripple through the water.

What a day for a day octopus

Day Octopus

Day Octopus on the moveThe trick to spotting an octopus is to see it in motion. I’ve seen one or two when they’ve been stationary, but only by accident, watching something else and realizing that there was something slightly odd about that ‘rock’ next to it.

When I do see an octopus, one of the first things I tend to notice is the siphon and the outdated facial recognition software that is my brain thinks, ‘that’s an eye.’ Except it isn’t.

In the top photo, the eyes of this day octopus can be seen at the highest point of the view. The siphon, orange on the outside and white inside, is below and a little to the right. The siphon, also known as the funnel or hyponome, is used for respiration, waste disposal, and discharging ink. It’s also used for locomotion. Water is taken in through the aperture around the siphon and then expelled out of the siphon, propelling the octopus in the opposite direction.

The bottom photo shows the octopus changing its coloration. They can change their color and texture to blend in with their surroundings. The middle photo shows the octopus saying ‘I’ve had enough of this. Arrivederci.’

Day Octopus on a rock

Varicose phyllidia

Varicose Phyllidia

This colorful little creature is a sea slug. As with many other nudibranchs, the bright coloring serves as a warning. They’re poisonous and, because of this, have no known predators. One tidbit I found interesting is that nudibranchs like this Varicose phyllidia, don’t produce their own poisons. Instead, they ingest toxins from their prey, such as sponges, and recycle it. So not just yellow and black and pale blue, but green as well.