Disguise artists make exploring underwater world a treat
All Hallows Eve is creeping closer. Revelers will soon parade in costumes while sticky spider webs and carved pumpkins adorn the lanai. Meanwhile, in Hawaiian waters, Mother Nature celebrates all year long . . . where one may discover as many tricks as treats!
The frogfish and the devil scorpionfish, or nohu, are fierce competition in any costume contest. They expertly blend into their surroundings relying upon a defense mechanism known as camouflage. Using coloration and texture, these incredible creatures mimic sponges and algae-covered rocks.
The 12 species of frogfish in Hawaii are nearly undetectable. These ambush predators remain motionless, perching on the reef. Suddenly, their mouth opens 12 times wider than their body and, sluuurp, their prey disappears! Researchers believe they may be capable of the fastest prey capture in the animal kingdom, yet frogfish don’t even swim. They move on leg-like fins with webbed feet.
Perhaps their most intriguing component is their “fishing pole.” In many species, the first dorsal spine has modified into the illicium (rod) and the esca (lure), which descend from the top of their heads. Wiggling the esca – resembling small shrimp, twigs, worms, fish or even feathers – attracts unsuspecting predators that soon discover that they are the prey. In deeper water, a type of frogfish known as the anglerfish emits an eerie jack-o-lantern like glow from its lure.
Also ambush predators, our 25 species of devil scorpionfish are quite devilish. They are adaptively camouflaged and virtually hide in plain sight. A brilliant flash of red, yellow and black signal danger as the nohu displays the underside of its pectoral fins. If the predator pursues, a venomous sting awaits.
These fish are amazing masters of disguise, but another reef dweller is an ominous predator capable of impressive trickery – the elusive octopus, or he’e.
They exhibit a myriad of textures such as puckers, ridges, bumps and, in true Halloween fashion, warts, changing colors and patterns instantaneously.
If this make-up artistry proves ineffective, a squirt of water or a thick cloud of ink will escape.
Quite possibly the most intelligent invertebrate in existence, he’e possess large brains, strong beaks, toothy tongues, poisonous saliva, three hearts, eight arms, approximately 2,000 sensory lined suction cups, tubular funnels, ink sacs, and the ability to swim backwards.
Another type of invertebrate, the sea cucumber, or loli, is more obvious. About half of the species in Hawaii are easily found on reefs or sprawled across sandy bottoms like velvet sausages. However, what might appear as an inviting free meal could have tragic consequences to predators such as crabs that become completely immobilized in toxic sticky threads excreted by some types of loli. Some even eject all of their internal organs through their anus, creating a decoy as they escape.
Beach-faring crabs such as ghost crabs, or ‘ohiki, don’t feed on loli. Living in holes dug in the sand, they come out to moisten their gills and to feed on other crabs and turtle hatchlings. ‘Ohiki can be white or black, taking on the color of the beach sand where they reside.
If relocated to a black sand beach, white ghost crabs will change to black crabs and likewise for black ghost crabs. Believed to be some of the fastest creatures in the world, the two Hawaiian species of ghost crabs can be seen moving at “ghost-like” speed over the sand in all directions.
Exploring Hawaii’s underwater world can be quite a treat with these and many other disguise artists. Please remember to respect marine life and view from a distance so you don’t get tricked too.
* Lauren Burgess is an ocean naturalist at the Maui Ocean Center. She has been a certified marine naturalist for more than a decade on Maui waters. She has completed ocean awareness training and has volunteered for many turtle watch programs on South Maui beaches.