Eagle Ray and entourage

Earlier this week at Mahukona we ran into a large Spotted Eagle Ray being followed by several Threadfin and Raccoon Butterflyfish. Not sure why the butterflies were following—either to clean parasites from the ray (we saw no evidence of this) or to pick up any tidbits the larger fish might scare or stir up? The ray swam at a slow, meandering pace, suggesting that it was not at all bothered by the butterflies’ attention. We watched for quite a while until the ray swam off.

A Threadfin Butterflyfish trailing the big ray. Water here was about 15 feet deep.

The ray made a number of slow, sweeping turns that seemed to momentarily disorient the butterflyfish entourage.

A Raccoon Butterflyfish has joined the Threadfins. Check out the ray’s duckbill-like upper lip.

We saw this large group of young Moorish Idols on the way back into the dock. A common but always enjoyable sight in the summer.

 

 

Kawaihae’s hung over gobies

Marla, Hai, and I spent a relaxed Sunday morning snorkeling around the landing craft platforms in Kawaihae Harbor. We were hoping to see the black frogfish that Hai had been seeing on one of the pilings, or maybe the lionfish that he’d seen there a time or two, but we pretty much just saw the usual suspects: a handful of nudibranch species, Gorgonian Gobies, featherduster worms, Hawaiian Dascyllus, etc.

A thick wire hanging into the water from the second landing craft platform is home to several Gorgonian Gobies. It’s amusing to watch as they periodically dart out from their stations on the wire to to snatch  passing particles of plankton, but these fish are so small—just over an inch long— that it’s hard for my and Marla’s old eyes to make out much detail. (Hai sees everything with his seeming supervision.) Examining photos after we got home we noticed that the gobies have bloodshot-looking eyes—a lot like mine would look after a long night of drinking back in the day. Like this:

One of several Gorgonian Gobies under the second platform. Look at that bloodshot eye! Gorgonian Gobies, also known as Sea Whip Gobies, are easily confused with the similar Wire Coral Goby. The latter are a bit smaller, have a less pointed snout, and are less reddish in color. Wire Coral Gobies are found pretty much exclusively on wire coral, while Gorgonian Gobies will live on anything shaped more or less like a wire or thin stick.

More of the usual suspects—a handsome family of Hawaiian Dascyllus.

Hawaiian Whitespotted Tobies among the Halameda on the rubble at the base of the breakwater. These cute little endemic puffers are very common throughout the Islands. So is Halameda, a pantropical genus of green macroalgae.

A nice sized Painted Nudibranch on the march on one of the pilings. These, Trembling, and Gloomy Nudibranchs can almost always be found at this site lately.

Goatfish season

Young goatfish are abundant on Hawaiian reefs in the summer. They’ve been especially numerous at Mahukona this month. The under-appreciated goatfish family, overshadowed by the showier butterflies and surgeonfish, has several really attractive members. Sidespot Goatfish are one of my favorites.

A youngish Sidespot Goatfish in about ten feet of water at Mahukona. Goatfish are capable of quickly changing the tone and contrast of their coloration. This one has adopted a ruddy, high-contrast look in an attempt to attract the attention of a nearby cleaner wrasse.

“Big” nudibranchs and search images

I mean bigger than one inch.

Most of the nudis in recent posts have been less than an inch in length—some less than half an inch. This one from last week at Kawaihae Harbor is all of an inch and a half. It’s Dendrodoris krusensternii, a relatively rare species in Hawaii with no common name. Hai, that preternaturally skilled critter finder, found it crawling on a piling a couple of weeks ago and brought Marla, Sandra, Jeff, and me out to see it last week. We swam out to the pilings where Hai’d spotted the nudi, but at first none of us could spot it. Luckily, I’d studied a photo of this thing that Hai had previously posted and I’d developed a pretty good search image*. A good search image—a visual idea of just what one is looking for—is really useful for spotting nudibranchs. Pretty soon I spotted this one on a partially dead Cauliflower Coral growing on a piling a few feet below the surface.

A Blue Dragon nudibranch from a dive earlier this month at a North Kohala site called Ulua. It’s about three inches long. We saw much larger specimens at Backside Molokini last year. These relatively active nudibranchs are supposedly quite common in Hawaii.

*Funny, if you Google “search Image” in 2019 you get a bunch of links telling you how to search for images on line. In this old guy’s world, the term means as described in this fascinating link: https://evolution.berkeley.edu/evolibrary/article/0_0_0/happyface_11

Speaking of Gargantuan…

Another fish that tends to briefly appear and then disappear at specific spots is the Gargantuan Blenny. I see these guys every now and then at Mahukona’s “First Point”, the shallow reef about a hundred yards northwest of the pier. They usually disappear into the reef before I can get a photo. This one I saw last week was unusually cooperative.

As the name suggests, the Gargantuan is Hawaii’s largest blenny. This one’s an enormous seven inches long. Hoover says that this endemic is fairly common, but is infrequently seen due to its preference for shallow, surgey habitats. I can vouch for the surgey part—with all the surge it’s never easy to hold still enough for a decent photo of these fish.

This is the closely related Scarface Blenny, photographed at Mahukona a couple of years ago. Another endemic, this species is smaller (4 inches maximum), more common, and more skittish than the Gargantuan.

Leaf Scorpionfish reappear—and disappear

Decades ago Marla had a sweet old German shepherd named Maddie. As with every other dog she’s ever owned, Marla walked Maddie through the neighborhood at least daily. One day, passing a certain house a few blocks from home, Maddie spotted a rabbit (or was it a squirrel?) and got the chance to excitedly chase it until she came to the end of her leash. This was apparently a big event for her. For years afterward she’d linger when she passed that house, in hope of seeing the rabbit again. Sadly, she never did.

I’m something like Maddie when it comes to unusual reef fish. I’ll return over and over, sometimes for years, to spots where I’d seen something special like a Leaf Scorpionfish or a Gargantuan Blenny. Sometimes it pays off. We first encountered Leaf Scorpionfish among the rocks near the Mahukona dock in November 2016. We went back to look for it a few days later and it was gone. From then on we made a habit of scanning the area for this fish on most of our Mahukona snorkels. Our perseverance paid off in July 2017 when we saw not one, but three Leafs dispersed near the dock. These, too, disappeared within a few days. One reappeared for a short time later in the summer and disappeared again. So after two discrete successes we naturally continued surveying the area, with no luck until last week, when a single, ivory-colored Leaf Scorpion appeared just a few feet from the swim ladder. A day later it was accompanied by another, smaller, darker specimen—maybe a mate. A day after that both were gone. I wonder where to these sedentary, relatively immobile fish disappear to for months on end. My guess is that they’re just hunkered down deep in the reef, safe from the prying eyes of us two-leggers.

Intricate patterns and textures, and those strangely vacant eyes.

August 2019 update: I just remembered that this Leaf Scorpion looks a lot like one I saw at Mahukona a couple years ago. So I looked at the old photos and it turns out it’s the same fish. Apparently it’s been hiding among the rocks and coral near the Mahukona dock for at least two years. Here’s a photo from July 2017:

This photo from 2017 shows the same brown markings on a cream colored background as the 2019 photo—it’s definitely the same fish. It seems to have grown a bit larger since 2017, but it’s hard to tell for sure.

A rare (-ish) morph of a common fish

Whitemouth Morays are pretty much everywhere on Hawaiian reefs. We see at least one poking its head out of the coral on most of our snorkel outings. Most are brownish with a dense pattern of small white spots, the size and density of spots varying quite a bit. On some individuals the spots almost merge, resulting in the appearance of a white background with brown reticulations. We ran into this morph the other day at Mahukona.

All Whitemouths are handsome fish, but the reticulated morph really stands out. This form is uncommon enough that there are no photos of it in either Hoover’s or Randall’s* books. (Hoover does mention this morph though.)

This is a more typical Whitemouth. The spots can often be larger and the background less reddish. In general, the larger the individual the smaller and less dense the spots. (At least that’s my impression.) This specimen is somewhat larger than the one in the top photo.

Another photo of the first eel, just for anyone who doubts that this is a Whitemouth. The white inside of the mouth (as well as a white tail tip) is a definitive identifier of this species.

*See the “About” page of this blog for Hoover’s and Randall’s books.