Hawaii's Gold Lace Nudibranch

by B. N. Sullivan

Halgerda terramtuentisContinuing our series on nudibranchs (see previous post on Exotic Underwater Nudies...), today we present the Gold Lace nudibranch (Halgerda terramtuentis). This pretty mollusc is endemic to Hawaii -- that is, it is only found in the waters around the Hawaiian Islands.

It has a pale yellow translucent body overlaid with a lacy network of irregular yellow-orange lines, and a solid yellow-orange line bordering the entire edge of its mantle. It also has little bumps, called tubercles, all over its body, which are a lighter color -- almost white on some individuals.

As if its body were not pretty enough, take a look at those accessories: Its tree-like gills and its rhinophores -- those sensory organs protruding from its head -- are white with black speckles.

While these little critters are found only in Hawaii, they are fairly common here. Both of the individuals pictured on this page were photographed at Puako, Hawaii, where the species is plentiful along the area known as the first dropoff, where they live in small cavelets and in rocky areas. We see them most often at relatively shallow depths -- less than 10 meters/30 ft.

I took both of the photos on this page inside a small cavelet. The individual in the photo above was crawling along the ceiling of the cave, and got dislodged by our exhaled bubbles. On impulse, I snapped a shot of it as it floated downward through the water, and amazingly, it turned out to be a pretty good 'species ID' shot! The second photo is more naturalistic. Because the nudie is crawling across a red encrusting sponge, you can get an idea of its 'see-through' translucence.

Halgerda terramtuentisGold Lace nudies are small -- usually between one and two inches (up to 5 cm) in length. They are carnivorous, but they don't "bite." They feed on sponges and other soft organisms.

This nudibranch was officially identified relatively recently - in 1982 - by Hans Bertsch and Scott Johnson of the University of Hawaii. (Many nudibranch species have been officially recorded in the scientific literature since the 1800s.)

By tradition, the scientists who officially discover a species get to name it. This creature's species name has an interesting story. Terramtuentis means "looking at the earth with care." The name was given in honor of a group of Earthwatch volunteers who assisted Bertsch and Johnson with their research.

7 comments:

  1. What marvelous pictures! Awesome!

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  2. That's got to be one of the prettiest sea creatures I've seen. It looks like a hat. I think it's kind of interesting that it's the same kind of white as the clown nudibranch. (I saw one at the aquarium - smile).

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  3. An exquisite little creature, with a lovely naming story. My son was born in 1982; this would be a terrific entry in one of those "The year you were born" lists.

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  4. They are both beautiful - but that first one is gorgeous! I swear - your work belongs in a museum, Bobbie!

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  5. Wow..these are truly amazing and beautiful creatures Bobbie,wonderful job in conveying their beauty!!

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  6. @ Antigoni - Thank you.

    @ 2Sweet - Looks like a hat? Imagine that!

    @ Lavender - I like the naming story, too. Good idea about the "in the year you were born" list.

    @ Kathy - Thanks. I'd like to think that The Right Blue is a little bit of a marine natural history museum.

    @ Bernie - Thanks a lot.

    Bobbie

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  7. Just want to say, that im doing a talk on endimics of hawaii and i just found this little dude floating over the reef and put him back on it, then i looked him up and found he was endimic and he can be in my presentation. not only that his name means looking at the earth with care. that is awesome! Terremtuentis!!

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Bobbie & Jerry

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