Our enthusiastic team of marine biologists will eagerly tell you about all the critters under the sea… where to look for them, and how to spot them when you're out on your own! Scroll below to get a glimpse of what to expect, and click on the images to read more about each creature's curious habits.

Humpback Whale

We are so privileged to share the ocean with Megaptera novaeangliae, the magnificent, majestic, magical humpback whale which spends the months of November-April in Hawaiian waters. It’s scientific name means “Long-finned of New England”. It’s long, light-colored pectoral fins (think arms) are so distinctive that the humpback is almost impossible to misidentify.  If that doesn’t give it away, the leaps (breaches), fin and tail slapping (lobbing), and other amazing acrobatic maneuvers will identify this gentle giant.  When this whale dives, they tend to arch or “hump” their back before going under, giving this animal it’s common name.  Here in Hawaii, where humpbacks come to mate and take care of their young, it is quite common to see a threesome of a newborn, its mother and a male escort. As you are whale watching in Oahu, listen closely and you may hear the escort’s haunting songs, whether through the hydrophone or while you are in the water this is truly a mystical thrill.

Spinner Dolphin (Nai`a)

Stenella longirostris, the Spinner Dolphin, is a protected species.  It’s species name, longirostris, means “long nose” and its long, slender snout is one of the ways you can easily tell this dolphin from others.  The dead give away though are the acrobatic leaps and spins they use to communicate, among other things,  with  members of their large pod.  In Hawaii, Spinners hunt in large groups at night then venture into the shallows during the day where they divide into smaller groups to rest and socialize.  To navigate, they use echolocation by forcing air through a hidden nostril at different frequencies, making the characteristic clicks and whistles you hear when in the water with them.  The melon, the round feature at the forehead, amplifies the echo.  The time it takes the echo to come back determines how far away an object is.  They receive it through the lower jaw.  When swimming with dolphins, it is highly discouraged to swim towards a resting pod, let them come to you.

Green Sea Turtle (Honu)

Chelonia mydas, the Green Sea Turtle, is the most common sea turtle seen in the islands.  They are a pretty common site on the reefs here, thanks in part to their protection under the Endangered Species Act.  Why are they called “Green” sea turtles?  It’s due to the color of their fat, which turns green because of their diet of algae and sea grass.  That’s right, it’s the inside of the turtle that’s green!  These reptiles can live to 100 years of age and do not mature until about 25 years old, where it is easy to tell male from female.  Males will have very long tails that extend past their rear flippers, while females will have shorter tails.  However, small individuals of either gender have the shorter tail, making it difficult to tell either gender apart.  As reptiles, they need to return to the surface to breath air periodically, which can be anywhere between 15 minutes to 5 hours!  Unique to Green Sea Turtles in Hawaii is the behavior of basking (sitting out on the beach).  Why turtles do this is not fully understood, it could be predator avoidance (Tiger sharks are the main predators), regulating their body temperature, or something not yet explained.  If you see one on the beach, don’t worry, it is part of their life cycle.  When viewing or snorkeling with these majestic Green Sea Turtles in Oahu, we highly discourage approaching them, let them come to you. Another interesting fact is when female hatchlings (baby turtles) mature, they return to the same beach where they were born when it’s time to nest!

Spotted Eagle Ray

One of the great pleasures in life is watching a graceful Aetobatus narinari (spotted eagle ray)”fly” through the water.  Yes, it has stinging spines on its tail for protection, but that does not mean that you need to be afraid of these docile animals.  Because of what happened to Steve Irwin, Australia’s famed “Crocodile Hunter”, people believe that stingrays attack.  Like any animal, including humans, they will protect themselves if they feel threatened.  But you have to be very close to them in order to get stung, which is not advisable with any wild animal unless you are specifically trained to do so.  And even an experienced person can get stung if they get too close.  However, be assured that these gentle animals will not attack you so relax and enjoy their elegance and beauty.  These, like other rays, are close relatives to the sharks in having a cartilage skeleton instead of one made of bone.

Spotted Boxfish

Ostracion meleagris, the Spotted Boxfish, is distantly related to puffers, but do not share many of the defensive strategies of puffers.  Their body is fixed except the fins, eyes, and mouth thanks to an armor plate encasing the entire body.  The females and juveniles are dark with white spots, while males have blue sides and orange spots in between the eyes.  This fish, like the puffers and porcupinefish, have toxins in their skin and secrete it when stressed.  Unlike the toxins in puffers and porcupinefish, the ones in this boxfish are not harmful to people.  They can swim surprisingly fast and are able to turn on a dime when needed.   You can find them close to the bottom cruising near rock outcrops searching for small invertebrates such as sponges and worms.

Porcupine Fish
(Kokala / `O`opu Kawa)

Diodon hystrix, the Porcupinefish, is very closely related to puffers, differing from puffers by the presence of spines on their skin instead of the smoother skin of puffers.  They share many of the same defense strategies with puffers including inflating with water, a powerful bite from their beaks, and being toxic to consume.  The toxin has been used as an ingredient in poisons that gave rise to the idea of “zombies”.  Porcupinefish have large eyes, indicating that they are nocturnal (active at night) and most of the time can be found under large ledges.  We highly discourage making a porcupinefish or a puffer inflate for entertainment, as it makes it difficult for the fish to move and it can take awhile for them to deflate.

Hawaiian Cleaner Wrasse

Labroides phthirophagus, the Hawaiian Cleaner Wrasse, is a fish with a very important job.  This fish (which is yellow, black,and purple in color) will set up a cleaning station on the reef and rid fish of parasites.  They advertise by moving up and down in a rhythmic way.  The client fish (such as this Manybar Goatfish), in response, will stop in front of the station and move their fins, giving the ok for the cleaner wrasse to go to work.  They will even go into a fish’s mouth if the fish needs a little dental cleaning!  This species of cleaner wrasse is also endemic to Hawaii, meaning it is found no where else in the world!

Blackside Hawkfish
(Hilu Piliko`a)

Paracirrhites forsteri, like other Hawkfish, lack swim bladders which would help them control their bouyancy in the water column.  As a result of this, these predators have a more benthic (bottom-dwelling) lifestyle.  Their large pectoral (side) fins allow them to perch on coral heads or rocks like a hawk, waiting for prey to come near them.  Once the prey comes within striking range, they dart and gulp the prey.

Green Linckia Star

Linckia guildingi is a slender star that is related to sea urchins, brittle stars, and sea cucumbers.  Like other stars, they have 5 arms.  They also have an interesting way of reproduction- like a gecko or lizard tail, one arm can break off.  However, unlike a gecko or lizard tail, that arm can form another animal.  These stars can be found between nooks and crannies of the reef.  Why does this animal not have a Hawaiian name, despite being a local species?  Animals with no Hawaiian names were animals that although Hawaiians recognized, they did not have an apparent use for the animal in their daily lives..

Red Pencil Urchins

Heterocentrotus mammilatus, like other sea urchins, are related to sea stars, sea cucumbers, and brittle stars in that they possess a five-part body plan (radial symmetry) and an internal system of canals and reservoirs called a water vascular system to use for breathing and filtering water.  Although appearing spiny, these urchins will not poke you.  Their spines are thick, broad, and a red hue can be left on hands and fingers that touch them.  They are important members of the reef, consuming algae, so it is highly discouraged to collect one of these animals.  Although possessing no eyes, their tube feet have genes that precede the retina in eyes of other organisms, allowing them to sense differences in light.  The tube feet are also what allows urchins to move and stick to different surfaces, hands included.

Whitepatch Razor Wrasse (Laenihi)

Iniistius aneitensis is a member of the Wrasse family.  The one pictured is a juvenile.  The adult phase has a white patch in the center- females will have a dark patch preceeding it, males will have a yellow patch.  This, like many of the Razor Wrasses, lives near sandy bottoms and can bury in the sand at “soft spots” when threatened.  They are locally called “Nabeta” (nah-bet-ah).

Common Box Crab

This little crab, Calappa hepatica, which could fit in the palm of your hand,  is called a spotted box crab or shamefaced crab because of the way it holds its pincers (crabs don’t have”claws”) in front of it’s “face”.  It can bury itself in an instant under the sand leaving only its eyes, perched on eyestalks like tiny periscopes, surveilling the waters above the sand. A lot of people think nothing lives on a sandy bottom but you would be surprised what you might find beneath the sand – seastars,  sand dollars,  fish, and funny little crabs.

Thanks goes to

Nick Brilliande for the write-ups and Keoki Stender for the photographs