Another record falls

Today Hai and Lottie were supposed to show us where the Blacktip Reef Sharks hang out at the south end of Kawaihae Harbor, but roaring offshore winds made us divert to Plan B. We went east to Kawaihae’s commercial docks, tucked away from the wind. There among the dock’s pilings we identified six species of nudibranch, breaking my short-lived personal record of five, set only three days ago.

After Marla and I got home I did a little web crawling and found that many nudibranch species are fond of vertical surfaces like those provided by Kawaihae’s pilings and pylons*. Who’d have thought.

These handsome, if not colorful, White Margin Nudibranchs are apparently quite common in Hawaii, but they were a first for me. Hoover writes that they are often found in small groups. We saw several pairs and a triple today.

This inch and a half long Gloomy Nudibranch was the only nudi we saw that measured over an inch. The species can reach three inches.

Here’s another Painted Nudibranch. Quite a contrast to the one shown in the last post. This species ranges all the way to the Mediterranean, which it apparently reached via the Suez Canal.

Another Trembling Nudibranch. Look at that supple body—the way it’s folded itself across the thin, stiff (at least by nudibranch standards) obstacle that it’s crawling over. This species is the only endemic in this post.

The White Bump Nudibranch looks quite a bit like the Trembling, at least to me. Not so much to Marla, who, unlike me, distinguished them instantly in the field. The colors of the gills and rhinophores—deep blue in the Trembling; pale grey and brown in the White Bump—are the main identifiers for me. Marla said it was more of a Gestalt thing for her. The body color difference so apparent in these flash photos was not nearly so apparent to me in the rather dim light around the pilings.

This was the highlight of the outing for me. It’s a member of the genus Caloria; maybe an un-named species or maybe indica. There’s a lot of confusion on the web regarding this. In either case, gorgeous but tiny and surprisingly hard to spot. We saw several—mostly spotted by Hai. (I don’t know what that little round thing below the nudi is, but I suspect it’s something planted by ancient aliens. Click and take a close look and I’m sure you’ll agree.)

*Actually, they’re all pilings. I’m really misusing the term pylon here, but we** use it anyway to refer to the piling supporting the military platforms. Actually, we’re misusing piling as well. A pile is a support column, while a piling is a structure composed of piles. Piling feels better somehow, maybe because it’s doesn’t sound like a hemorrhoid.

**By “we” I mostly mean Jeff and me.

Kawaihae impresses again

Yesterday Marla and I, along with our friends Hai and Lottie, visited the huge concrete platforms that the military landing craft tie up to in Kawaihae Harbor. Hai had messaged me the other day that the nudibranchs had returned to the massive concrete pylons that support the platforms. Last July I posted on the surprising variety of nudibranchs and other interesting invertebrates living at this unlikely location. (https://onebreathkohala.wordpress.com/2018/07/21/kawaihae-surprises/) The nudis disappeared over the winter, but they’ve returned, seemingly in greater abundance and diversity than we’d seen last summer.

We spent over an hour free diving among the pylons, finding nudibranchs and other good stuff as deep as twenty feet, where the pylons hit bottom. We identified five different species of nudi—Gloomy, Painted, Trembling, Decorated, and Kahuna.  I’d seen and posted photos of the first three species in July, but the last two were new to me.  I struggled with my little Olympus point’n’shoot camera, having inadvertently gummed up some settings, but still managed to get some recognizable shots.

This little Trembling Nudibranchs has bunched itself up into an ovoid shape in contrast to the more elongated proportions this species more commonly assumes.

A gorgeous Decorated Nudi.

A tiny Painted Nudibranch that Lottie found drifting next to the pylons. She held it in her hand for me to photograph. I’d seen and photographed this species before, but the individual I’d previously seen was much less conspicuously marked than this one. This one looked so different from the earlier one (and from the illustration in Hoover’s Hawaii’s Sea Creatures) that I initially doubted Hai when he called it a Painted. A little web research when I got home revealed that Hai was correct. Discussing it later, Hai and I agreed that this is an unusually variable species.

This was the hit of the trip for me—a Kahuna Nudibranch. The little fellow, around fifteen feet deep at the base of a pylon, was maybe half an inch long. That color made it fairly easy to spot though. None of the nudis in this post were longer than an inch.

More flotsam

The water at Mahukona was full of floaty stuff yesterday.  This happens fairly often, when the prevailing tradewinds die and are replaced by on-shore breezes.  The on-shores bring in plankton and all sorts of other things from deeper offshore waters.  Sometimes they bring stinging jellyfish (as described in the December 2016 post entitled The Pink Menace), but yesterday it was primarily tiny, nearly invisible creatures, which the various species of plankton-eating reef fish rose up to dine on.  (Yeah, I know, dangling participle.  I’m pretty sure it’s allowed in this rapidly unravelling 2019 world.  Heck, if the President can say “bullshit” at a rally, I guess I can dangle a participle.)  The upper water column was loaded with feeding Hawaiian Sergeants, Indopacific Sergeants, Black Durgons, Thompson’s Surgeonfish, Milletseed Butterflies, and others.

The great thing about days like this—and ocean snorkeling in general—is that you never know what else will drift in.  In this case it was a tiny creature bobbing around randomly in the upper few feet of the water column, in water about ten feet deep. It was rolled up into kind of a lumpy ball shape about half an inch across, and we initially had no idea what it was—animal, vegetable, or mineral; alive or dead.  But it looked intriguing enough that I had to play with it.  When I handled it, it opened up into a flatter shape, and appeared to try, slowly and not very efficiently, to swim away.  With our presbyopic vision, we still couldn’t figure out what it was, so I took some pictures and we let it go on its way.

When we got home and looked at the photos we saw that the object of our interest was a Gold Lace Nudibranch.  This is apparently a common endemic species, but neither of us had seen one before.  It’s usually, like most nudis, found crawling on the bottom.  I did a Google search and could only find one photo of a Gold Lace swimming freely.  I guess this one was trying to move to a new neighborhood.  Here’s what it looked like:

Our free-swimming Gold Lace Nudibranch. Out in the water we weren’t able to make out the frilly little blue-black protrusions in the photo. Once we looked at the photo it was clear that these structures were rhinophores and gills—organs possessed by nudibranchs. (All nudibranchs, aka sea slugs, have external gills—nudibranch means “naked gill” in Latin.  Most, if not all, also possess rhinophores, an external chemosensory organ.) With the help of John Hoover’s Hawaii’s Sea Creatures we figured out that this was a Gold Lace. The species barely reaches an adult length of two inches—this one was probably a little under an inch fully unfurled.

Here it is completely unfurled in my hand.  I’ve never seen a photo of this species with wings like this. Their bodies are normally more elliptical. Maybe they assume this winged shape when they swim.

We often run into floating debris when the on-shores are blowing.  Objects that have been in the water for any length of time accumulate marine growth, and often a collection of juvenile fish using the object for shelter. A lot of different fish species congregate around floating objects as juveniles, prior to settling out on the reefs as they get a bit older.  Individual species are difficult to identify, partly because the popular books don’t typically show this stage.

Juvenile chubs (I’m pretty sure they’re chubs) nervously clustered around a floating plastic bottle. We always make sure to examine any marine debris we encounter, either while snorkeling or kayaking.  The pleasure of never knowing what you’ll find.

A foraging Eagle Ray

Spotted Eagle Rays are a pretty common—and always welcome—sight on Hawaiian reefs.  Usually they’re either milling around or cruising from point to point, often in small groups.  Sometimes we see them foraging in the sand for buried invertebrate prey.  This one at Mahukona foraged for several minutes, ignoring us as we watched.

Rooting around, creating clouds of sand.  Eagle Rays are believed to have special sensory organs in their snouts that detect the electromagnetic signatures of their buried prey.

A closer look at this medium-sized ray, about four feet across.  The multiple poisonous tail barbs, as well as that cool looking vertical tail fin are apparent here.  This individual, like many, is kind of beat-up looking, the snout in particular showing the wear and tear of years of rooting around in rocky sand.  Hoover tells us that Eagle Rays have among the highest brain to body size ratios of any fish.  (Morays have among the lowest.)

Here’s a smaller specimen we ran into at Makaiwa Bay last week.  It’s lost its tail, probably to a would-be predator.  Broken tails are not uncommon, but usually the loss involves just the long, filamentous portion. Like so many fish, this one seems to be coping with the mutilation quite well.

 

Some South Kohala eye candy

Last week Marla and I took a couple of dives off Puako with Blue Wilderness.  There were a handful of beginners  on the boat this day, so we dove two shallow sites—about 40 feet.  Neither site was all that exciting, but both were quite fishy, full of the usual suspects.  Here are some of the prettier or more interesting ones:

I still sometimes have trouble distinguishing between the Big Longnose Butterflyfish* shown here and the similar (not big) Longnose Butteflyfish. This photo highlights two distinguishing features of the Big Longnose—an extremely long snout and a sprinkling of black flecks on the chest.

A handsome adult Orangebar Surgeonfish.

The pale fish near the center of this photo is a juvenile Orangebar Surgeon, together with some Goldring Surgeonfish, Brown Surgeonfish, and Yellow Tangs. Like I said, a pretty fish-rich site.

A young Yellowtail Coris with a couple of juvenile parrotfish (two different species it looks like).

A juvenile Banded Urchin (right) and a Rock Boring Urchin (left). I’d never seen a juvenile Banded Urchin before. The flattened spines (which disappear on adults) are unique and rather eye-catching. That Rock Boring Urchin has actually excavated the hole into which it is nestled.

A tiny Trembling Nudibranch, only about a half inch long. I’d have never spotted it without the help of our dive guide. Regular readers (ha, if there are any) may recall that we saw one of these on a piling at Kawaihae last year.

An enormous Stripebelly Puffer. This thing must have been a foot and a half long. Hoover says it’s Hawaii’s largest puffer. We frequently run into smaller specimens snorkeling at Mahukona and other sites.

*I’m using Hoover’s nomenclature here.  Reef.org and many others call the Longnose Butterflyfish the Forcepsfish and refer to the Big Longnose Butterfly as Longnose Butterfly.  Some use Common Longnose Butterflyfish for the Forcepsfish.  Sheesh.

Mahukona hermits

After returning from yet another mainland trip the other day, Marla and I took a fast, cold snorkel at Mahukona.  Marla wanted to keep moving in order to stay warm, and I followed.  It was nice and clear and fishy, but we didn’t really see anything of interest, and Marla soon went in to enjoy Mahukona’s solar-heated “shower,” a hose bib fastened to a rock wall in the parking lot.  I decided to linger for a while near the dock.  The area close-in to the dock is surprisingly productive—it’s the only place in Hawaii where we’ve seen Leaf Scorpionfish*, and we’ve spotted all sorts of eel there, as well as hybrid tangs.  This day the surprise was a sizable group of Hawaiian Elegant Hermit Crabs huddled among some large boulders in the surge zone just a few feet from the dock wall.  These little beauties are not uncommon, but I’d never seen so many at once—at least ten.

Hawaiian Elegant Hermit Crab living in the shell of a Mulberry Drupe, another common species.  The shell is about an inch across.  Check out those striking blue eyes!

Another hermit, this time in a shell I can’t identify.  (Probably easy to identify, but whatever it is, it doesn’t appear to be in Hoover’s Hawaii’s Sea Creatures book, which is my only handy resource.)

Coming back in toward the ladder I ran into a more tame than usual pair of Sailfin Tangs. This one accommodated my desire for a photo by flaring its dorsal fin.

*As of this post I’m capitalizing English common names for fish and other creatures, joining John Hoover, my good friend Jeff Hill, and many others.