A Whitetip checks me out

Yesterday I took advantage of unusually calm conditions to take along swim from Mahukona to Nishimura Bay, a little-know spot about a half mile to the north. Just short of Nishimura a Whitetip Reef Shark cruised by going in the opposite direction. I turned to follow it and, contrary to to my usual experience with this species, the shark turned toward me and did a circle around me at a distance of maybe fifteen feet. I’ve got to admit that this made me just a bit nervous, but I was confident in my book-learnin’ that unprovoked attacks by Whitetips are vanishingly rare. So I grabbed the little camera out of my pocket and took a few shots—what else would I do? The shark quickly lost interest and swam away in that oh-so-calm manner characteristic of largish sharks, leaving me stoked.

The Whitetip giving me the eye. A lot of spearfishing goes on in this area, and it could be that this fellow, about five feet long, was wondering if I happened to have a stringer of recently speared fish that it could snatch. I’ve read that the pattern of dark spots on the flanks can be used to identify individual sharks.

More cleaners—and happy New Year

I’ve been spending more and more time at the close-in Cleaner Wrasse station at Mahukona. It’s great fun watching the complex interactions between cleaners and cleanees, as well as among the cleanees. There’s a lot of jockeying for position and chasing. The posing fish are clearly eager for the wrasses’ attention, expecting to have a parasite or excess bit of mucus removed. But the little cleaners often double-cross the cleanees by taking a bite of living skin, to the subject’s obvious annoyance. From earlier this month:

Manybar Goatfish posing for cleaning. The reddish color they’ve assumed here is also their typical night coloration. Many species of reef fish turn reddish at night. Look at those extended barbels.

A Manybar Goatfish showing its normal daytime colors. (From 2017.)

Away from prying eyes

When snorkeling or diving we routinely look deep down among the branches of any cauliflower or antler coral we pass. You never know what you’ll find in there—these corals (what’s left of them after the 2014-2015 bleaching event) provide shelter to a wide variety of fish and invertebrates. I posted a photo of a guard crab hiding in an antler coral back in June. Here’s what we saw yesterday in a cauliflower coral at Mahukona:

A Speckled Scorpionfish peering back at the camera. This common endemic is, according to Hoover, one of several scorpionfish that inhabit branching corals in Hawaii. While we see Speckled Scorpions quite frequently, they usually present a side view or tail view to to the camera (see my November 25, 2016 post), so I was pleased to get this head shot. This fish was about two inches long in water about ten feet deep.

This Hawaiian Coral Croucher was hiding even deeper in the same coral head. Fairly common, but notoriously hard to photograph, these shy endemics are related to scorpionfish. The velvety appearance of the skin is a distinctive characteristic of this family—Caracanthidae. About two inches long.

Opportunists

Butterflyfish, with their tiny mouths, subsist mostly on tiny prey—coral polyps, small polychaete worms, amphipods, etc. But given the right opportunity, many (but not all) butterflyfish species will dine on all sorts of other things. Dead fish or larger invertebrates on the reef attract the attention of butterflies and many other fish. There’s often quite the crowd of opportunistic feeders gathered around the corpse, all so fixated on a chance for an easy meal that intruding photographers are largely ignored. We’ve seen a handful of these events at Mahukona recently.

Lined Butterflyfish are known to be difficult to approach and photograph. Attracted by the floating body of a half-eaten Hawaiian Whitespotted Toby* (below the butterflyfish on the left), these two allowed me to get quite close. Other species enjoying the free meal include the ubiquitous, highly opportunistic Saddle Wrasse, as well as Black Durgons, Pinktail Triggerfish, and a Yellow Tang.

These Fourspot Butterflyfish (you’ve got to count the spots on both sides of the fish) have found a broken-open sea urchin. Saddle Wrasses have joined in. Both this and the previous photo were taken at Mahukona.

We were snorkeling at Manase in Samoa in 2017 when we spotted a melee of fish swirling around a head of Acropora coral. We couldn’t identify what was attracting them—it was hidden deep in the coral—but it was apparently a dead something. Most of the crowd consisted of Sixbar Wrasses (a close relative of Hawaii’s Saddle Wrasse), Convict Tangs, and Orange-lined Triggerfish. While we were watching, this huge Longface Emperor and its companion showed up out of nowhere to see if they could get in on the bonanza. The emperors were apparently attracted by smell or by the frenzied activity of the smaller fish, or?

A closer look at the Longface Emperor. This thing was almost three feet long—big enough to startle us when it showed up. The species eats a wide variety of invertebrates and fish.

*Kind of strange to see a dead toby being fed upon by such a wide variety of fish. The bodies of these, like all puffers, contain a potent toxin to deter predation. Either these fish are immune or they know how to avoid the most toxic parts of the body, like the Japanese fugu chefs who prepare puffers for human consumption.

More tiny blennies

In September I posted a photo of a little Gosline’s Fang Blenny poking its head out from a hole in the reef. It’s easy to spot the fang blennies because they spend most of their time swimming conspicuously above the reef, only retreating to their hidey-holes when they feel threatened. There are other types of blennies that occupy these holes, but, while supposedly quite common, they’re a lot harder to spot. That’s because when not in their holes they tend to lie motionless on the reef, blending in with their cryptic coloration. I’ve been seeing them a lot more often recently—maybe because I’m getting better at finding them. Here are a couple from recent snorkel outings:

A Bullethead Blenny peering out from its hole in about three feet of surgey water at Mahukona. It lay motionless—and quite hard to spot—on the reef until I approached, when it shot unbelievably quickly into its hole, tail-first. This one was about three inches long—they reach about four inches. There’s a photo of this species lying exposed on the reef here: https://onebreathkohala.wordpress.com/2015/11/11/hapuna-beach-its-not-just-for-boogie-boarding/

A Strasburg’s Blenny at Hapuna Beach. Like the Bulletheads, the Strasburg’s lives mostly in shallow, surgey water. The surge on this day made it difficult to get much of a photo of this little guy. The fact that its head was just a few millimeters across didn’t help. These endemics are among Hawaii’s smallest blennies, maxing out at only two inches.

 

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.