Our friend the cleaner wrasse

I’ve been spending a lot of time near the cleaning station just off the corner of the Mahukona dock. Two Hawaiian Cleaner Wrasses have occupied this station for many months. All sorts of reef fish come by and pose to be groomed by the little wrasses. It’s a great place to just linger and watch as the fish queue up for cleaning, sometimes chasing each other around, and doing other interesting stuff.

A Goldring Surgeonfish (kole in Hawaiian) poses for cleaning at Mahukona.

An Orangespine Unicornfish queued up along with a Yellow Tang and a Goldring Surgeonfish. Shortly before I took this photo I watched this unicornfish chase off another individual of its species that was also lined up for cleaning. After it had chased its rival at least 20 feet away it hurried back the lineup.

The Hawaiian Cleaner Wrasse is endemic to Hawaii, but three other members of its genus are distributed through the Indo-Pacific. Cleaner wrasses have been getting a lot of press lately. A 2018 National Geographic article describes research showing that Bluestreak Cleaner Wrasses are capable of recognizing their own image in a mirror—the only fish known to be able to do this. https://www.nationalgeographic.com/animals/2018/09/fish-cleaner-wrasse-self-aware-mirror-test-intelligence-news/ Another 2018 article in The Atlantic describes research suggesting that not only do cleaner wrasses benefit the physical health of the fish they service by removing energy-sapping parasites, but they also boost the intelligence of the other fish, again, by removing parasites. https://www.theatlantic.com/science/archive/2018/03/the-fish-that-makes-other-fish-smarter/554924/ If you’re reading this post you should definitely check out both of these fascinating articles.

Here’s a Bleeker’s Parrotfish posing for a Bluestreak Cleaner Wrasse in Bali. I could not have gotten this shot were the parrotfish not holding still for the wrasse.

A Bluestreak getting into the gills of a Doublebar Rabbitfish, again in Bali.

A big Emperor Angelfish posing for a Bluestreak; Bali.

Even the hyperactive Scissortail Fusiliers stop occasionally for a cleaning; Bali.

The appropriately named Bicolor Cleaner Wrasse, a slightly larger, somewhat less common species; Bali.

Reason to take heart

There’s a bit of sadness attached to snorkeling or diving the Hawaiian reefs these days. The reefs have just not been the same since the coral bleaching event of 2014-2015. There’s a lot less coral around and considerably fewer fish. Sadder yet, we appear to be headed into more bleaching this year. But there are still a lot of fish around. The other day Marla and I swam through this enormous school of Barred Jacks at Hapuna Beach. Seeing this abundance, similar to that still often encountered in Bali and other South Pacific locations, lifted our spirits. A little, anyway.

Several hundred young Barred Jacks cruise the sand at Hapuna Beach.

Here you can just make out the faint vertical bars that give this species its name.

Hi there!

We saw this Gosline’s fang blenny earlier this month at Mahukona.

When approached, these irresistible little guys back into wormholes in the coral and stick their heads out to observe and wait for the intruder to leave. Confident once in their refuge, they allow very close approach. They’re tiny—the head is smaller than the end of a pinky finger.

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 find 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 located 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