dive | Garden Isle Divers

August 28, 2018April 12, 2019

What? I Don’t See It

A few years ago there was an ad campaign that ran in several national level magazines.

image of a US Navy Seals recruiting ad — Navy Recruiting Ad

The ad was designed to promote recruitment to the US Navy Seals. It had a picture of a swamp and a caption underneath that said “Pictured from left to right . . .” I’m guessing that there really were soldiers hidden in the picture but the only thing I know for sure is I never could see them.

I think of that ad when I consider the unique characteristics of a Commersons Frogfish. Like a special forces soldier, the frogfish is aggressive and fearsome. Unlike a special forces soldier, though, only fish need to fear a frogfish.

The Waikiki Aquarium says on its frogfish page that “The frogfish is superbly adapted for its habit of ambushing prey.” The article explains some of the adaptations which make that statement true. First, the fish’s head is mostly mouth which enables it to swallow other fish as large as itself. Second, the fish’s small gill openings are tucked away behind the pectoral fins so that exhaled water will not reveal the fish’s presence to potential prey. Third, and this is the part that reminds me of the Navy recruiting ad, is that frogfish are so good at camouflage that they can be difficult to distinguish from the section of reef they are situated upon. They sometimes even have real algae growing on their skin!

image of a frogfish — Yellow Commersons Frogfish

When we scuba dive Kauai, we have the opportunity to view a number of creatures that are skilled at camouflage but frogfishes are among the most specialized of ambush predators; their camouflage is so effective that biologists call it “aggressive mimicry”.

As members of the same family as the deep sea Anglerfish, frogfish have a special spine that they can use as a sort of “fishing pole” to lure in a potential meal that needs to get just a little bit closer to be food. When an unlucky creature gets to within about the distance of the frogfish’s body length, the frogfish will open its cavernous mouth so quickly that the rapid suction will draw the prey into its mouth. This whole process takes place in just six to ten thousandths of a second, making this one of the fastest capture mechanisms in the animal kingdom.

We have several resident frogfish living at Koloa Landing – one of Kauai’s best dives. It is a virtual certainty that we pass by at least one of them on any given dive tour. The trick is to actually see one. For your best chance at coming face to face with a frogfish while scuba diving Kauai, book a tour with Garden Isle Divers today!

March 19, 2018April 12, 2019

I Wanna See More of Those!

For as long as I’ve been a diver, I’ve been particularly excited to get to see a nudibranch. The first part of the name ‘nudibranch’ does mean “naked” but that has nothing to do with why they’re exciting to see!

The word “nudibranch” comes from Latin; “Nudi” means ‘naked’ and “branch” is ‘gills’. So, we are talking about an animal that, in most cases, has gills external to its body. Obviously, this is not normal animal kingdom type stuff!

image of a Gold Lace Nudibranch — Gold Lace Nudibranch

In the image of the Gold Lace nudibranch, notice the feathery looking stuff near the lower part of the body – those are gills. To put this in a totally inappropriate perspective, our president spends a lot of time talking out his tail while some nudibranchs spend their lives breathing through theirs. Does this mean they’d be good candidates for vice-president?

According to the World Registry of Marine Species there are currently at least 2,300 species of nudibranch that can be found throughout seas worldwide. While the greatest diversity can be seen on shallow tropical reefs, some have been discovered at depths exceeding 8,000 feet.

Now let’s get to the part about why I’m particularly excited when I get to see a nudibranch. As it says on Wikipedia “This group includes some of the most colorful creatures on earth.” As I say “These things are awesome!” It’s this colorful nature that makes them so fun to see. To put it simply, many are just plain spectacular.

If you’ve read some of my other posts then you might be starting to figure out that I’m pretty much a total nerd.

image of Orange Cup Coral — Orange Cup Coral

One sign of that fact is that I think it’s super cool how nudibranchs have a variety of ways to defend themselves. Since they are just slugs and couldn’t hope to outrun or outmaneuver larger predators, they’ve developed a variety of passive defenses instead. Some individuals have developed coloration patterns that mimic their primary food source. If the Cup Coral nudibranch was hanging

image of a Cup Coral Nudibranch — Cup Coral Nudibranch

around inside the Orange Cup Coral would you see it?

Other nudibranchs go the exact opposite route and have such intensely bright and contrasting color patterns that you couldn’t possibly miss seeing them. In these cases the bright colors are believed to signal to predators that the creature is either poisonous or intensely distasteful.

image of a Varicose Phyllidia — Varicose Phyllidia

And then, there are some – like the Blue Dragon – that can take stinging cells (nematocysts) from the animals they eat.

image of a Blue Dragon Nudibranch — Blue Dragon Nudibranch

This type of nudibranch is capable of eating these nematocysts and relocating them, through their digestive organs, along their bodies where they will then provide a defensive system for the nudibranch.

All of this is in sharp contrast to a creature like me who has primarily relied on an obnoxious personality and sarcasm as a form of keeping potential threats at a distance. In actual practice, this plan frequently backfires and actually creates enemies that didn’t previously exist. Again, our president. . .

I could go on listing interesting nudibranch facts but I think I’ll just post a few more pictures of some of the one’s we see while scuba diving on Kauai instead.

October 17, 2017April 12, 2019

There be dragons here

Dragons, as most people understand them, are mythical creatures – huge fire breathing reptiles that can fly and sometimes even speak human language. That idea is nonsense but dragons do exist!

image of A Small Dragon Moray — A Small Dragon Moray

According to the Maui Ocean Center, there are 42 species of eel that can be found in Hawaii. According to everybody who knows their eels, the Dragon is the most exciting. I had a client recently who came here from Zurich, Switzerland hoping to see “the Holy Grail of eels.” Smart move on his part coming to Kauai because our local dive site, Koloa Landing, is famously popular for the great chance of finding one.

image of a dragon moray — Adult Dragon Moray Eel

Dragons can grow up to three feet long and are skilled predators of fish and octopus. They have nostril tubes at the tip of their snout and a second pair above their eyes that look like horns. The “horns”, together with a curved mouth and needle sharp teeth make the Dragon Moray appear ferocious. In reality, if you keep your hands to yourself you are completely safe. That is a lesson that we, as divers, should apply to all creatures on the reef – keep your hands to yourself.