Say hello to this little tidepool goby. It's a frillgoby, in the genus Bathygobius, one of three frillgobies in Hawaiʻi. Is it a whitespotted frillgoby or a cocos frillgoby? Hard to tell, unless youʻre willing to count scale rows and fin rays (thanks for the i.d. help, Keoki Stender and the extensive website: MarinelifePhotography.com), but both are common in our tidepools, and both can display a banded pattern at will. The flathead, a.k.a cheekscale frillgoby is another possibility, though it tends to have a wider, flatter, and darker head. All the frillgobies here are small guys, getting no longer than three to four inches, and gobies in general, are small fishes, and bottom-feeders. The frillgobies tend to make good marine aquarium pets, as they are pretty happy-go-lucky towards tankmates, though not so much to their kin. Gobies are known for their fused pelvic fins that help them hold fast against the wave surges, or in the freshwater species, (ʻoʻopu wai) against the stream flow as well as in locomotion upstream to their niche. No matter that the force is not with them.
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Todayʻs post features the flashy and silvery āhole, as tasty today as they were in days of old. Their high tolerance for fluctuating salinities and temperatures made them an excellent choice for fish ponds, and they were also used in ceremonies "to chase away evil spirits and for love magic" according to Nā Puke Wehewehe ʻŌlelo Hawaiʻi. These flagtails have a deeply forked tail, large eyes, and can reach sizes around eight or so inches. During the day, adults school on or near coral reefs where they get plenty of wave action; at night they disperse to forage. Subadults can be found congregating in fairly shallow waters. Waiāhole on Oahu and Keāhole Point on the Big Island are two place names that reveal the prevalence and cultural significance of the āhole.
Until recently, it was thought that there was just one species of āhole here; fisherman, though, recognized two morphotypes, and recent DNA analysis* has confirmed the knowledge of the locals. Kuhlia xenura and Kuhlia sandvicensis are difficult to tell apart, but as juveniles (juvies are called āholehole) Kuhlia sandvicensis sport zebra-like markings on the head, favor tidepools with an open-water connection, and do not appear to venture well up into freshwater streams as their more abundant counterparts do. Despite its species name, Kuhlia sandvicensis is not endemic to Hawaiʻi, but xenuria is - this mix-up a result of the earlier taxonomic confusion. No matter to the fishermen though, who know theyʻre both ʻono loa. * ASPECTS OF THE BEHAVIORAL ECOLOGY, LIFE HISTORY, GENETICS, AND MORPHOLOGY OF THE HAWAIIAN KUHLIID FISHES by Lori Keene Benson, 2002. Visit any of the many tidepools here in Hawaii and you will likely meet up with Istiblennius zebra, known locally as pāoʻo, zebra rockskipper, zebra blenny, or jumping jack. Their color can range from blackish to greyish brown with vertical banding, hence the zebra name. They are a bit comical looking, with a blunt, froggy mouth and froggy eyes, and an upright flap atop their head. And speaking of froggy, these guys can hop! Being tidepool residents, pāoʻo are quite wary of predators, and will dart under a rock, or leap on over to a neighboring tidepool for a quick get-away. They can slither their long, laterally compressed bodies like an eel, and seem to favor curling their tails around like a "J" when resting. Similar to other blennioids, they have a long dorsal fin, and are scaleless. Pāoʻo spend much of their time resting or feeding on the bottom, in search of detritus or algae. Females lay eggs, which they cement into small nooks or under ledges; the male guards the cluster until the fry emerge. The little ones take to the sea for a time, eventually returning to the pools. Abundant. What a refreshing word to use to describe one of Hawaii's endemic critters. This is the saddle wrasse, hinalea lau-wili, Thalassoma duperrey, one of the most common reef fish found here. And while wrasses can be tricky to i.d. due to the color changes they go through from juvenile to adult, the adult saddle wrasse design is pretty straightforward. The generic epithet, Thalassoma, comes from the Greek thalassa: the sea, and soma: body; and indeed, the green and blue body is the color of the sea, which would make it tough to spot if it weren't for that blazing red-orange saddle. Another thing to look for is the way they swim: wrasses beat their pectoral fins up and down like wings, rarely using their tail fins unless a quick get-away is in order. As juveniles they sport brown, black, and white snout to tail stripes, but will begin the color change when they are around two and a half inches. As adults, they typically get to be around six to eight inches, but can get larger, with the biggest coming in at around eleven inches. They inhabit rubbly areas, lagoons, and reefs, where they spend their days in search of crustaceans and other invertebrates, as well as fish eggs and limu. It has been reported that they will engage in cleaning behavior, plucking ectoparasites off of other fish for a quick meal. It is believed they all begin life as females, with some of them going through sex reversal, becoming males. The largest are known as supermales, and show a white streak behind the orange saddle. At night, saddle wrasses may literally bury their heads in the sand, snuggling in for a good night's sleep.
When you are considered a tasty morsel by dolphin, tuna, mahimahi, and other fast swimmers of the ocean, you better have a pretty good get-away plan. The flying fish, or mālolo take to the air. Sculling their tails rapidly, spreading their elongated pectoral fins, and then angling upwards, they break the surface of the water. Once air-born, they catch updrafts and then glide for as long and as far as they can. While they cannot beat their pectoral fins like true wings, the airfoil curve of the appendage helps create lift, and they can tilt them a bit to bank left or right. The record for maximum time aloft is 42 seconds, time enough to befuddle a hungry predator. A distance of a hundred feet or more can be covered in a single bound. Ah, but mother nature isn't going to let these mighty leapers off so easily: waiting above are a myriad of hungry sea birds. 'Iwa, noio, and 'A (frigatebird, black noody, booby) are just a few of the birds adept at skimming low over the ocean's surface, mouth agape to scoop up an unlucky malalo.
There are nine species of flying fish that inhabit the waters around Hawaii, and some forty plus species worldwide. They prefer the warmer waters, and will migrate towards or away from the equator to find the ideal temperature. Summer is when they are most abundant here off-shore. Sailors have occasionally reported flying fish landing on their decks, including the lelepo which flies at night, often attracted by the on-board lights. Flying fish lay their eggs on anything that floats, such as driftwood, palm fronds, and even plastic debris. The eggs are also tasty to sea birds, and some researchers infer that the large amounts of plastic found in the bellies of albatross may be due to their ingestion of it while gathering mālolo eggs. Humans enjoy the meat and roe as well; tobiko is a type of sushi featuring the eggs of the Japanese flying fish. In Hawaii, the mālolo were eaten raw, or wrapped in ti leaves and cooked. Right here in the waters off of Hawaii, is a most fantastic creature: the hahalua, known to scientists as Manta alfredi. Though their size may be intimidating, reaching up to an impressive 15 foot or so wingspan and 3000 pounds, they are gentle and graceful, soaring through the coastal waters on "wings" as elegantly as the 'iwa bird soars through the air above them. As recently as 2009, manta rays were split into two species: Manta birostris, the giant manta ray, the larger of the two and migrating across open waters (rarely seen here), and Manta alfredi, the reef manta ray, which is also pelagic, but is resident and prefers coastal waters. Groups are known to frequent the waters around the Kona coast of the Big Island and the channels of Maui Nui. Their cartilaginous skeletons put them in the same class as sharks and skates. The "wings" are actually elongated pectoral fins, and their flattened saucer-shaped bodies end in a whip-like tail, though it lacks a spine or stinger, unlike the tails of eagle rays and stingrays, which also inhabit Hawaiian waters. Off the front of the head of the reef manta are the cephalic lobes, which are unfurled when feeding and curled up when swimming, resembling horns, thus the nickname "devil ray." While the smaller stingrays and eagle rays feed off mollusks and other bottom dwelling invertebrates, the hahalua is a filter feeder of zooplankton. It may swoop and loop as it feeds, somersaulting through the water as the cephalic lobes funnel the drifting plankton to the gill plates, which in turn, remove them from the water. Hahalua are countershaded: generally dark above and light below, and may have splotchy makings on the belly, which help to identify individuals. It is not uncommon to find a "Y-shaped" light-colored marking from the head that fades as it stretches to the back of the manta ray. The ends of the wings may also be whitish. They are slow growing, long-lived, and have a low fecundity (reproductive capacity). According to the NOAA fisheries website, their gestation period is thought to last 10-14 months, with the female birthing usually one pup every two or so years.
Familiar to snorkelers in Hawaii and throughout the Indo-Pacific is this well-known reef fish, the Moorish Idol, also known as kihikihi, or Zanclus cornutus. Their bright bands of black and white smudged with yellow and their distinctive crested dorsal fin make them a real stand-out. Oh, but not so fast. Enter the Pennant Butterflyfish, another fish found in Hawaiian waters, that at first glance looks so similar you might be in for a case of mistaken identity. Not to worry, today's post will help you to see the Moorish Idol's true colors. For starters, notice the tail colors: the moorish idol sports a black tail trimmed in white while this butterfly species has an all yellow tail. The butterflyfish also lacks the yellow blush in the central band of white. Next observe the snout. The idol has an orange dollop atop the snout; the butterfly's is all white and less pronounced. Another key difference is the scales; they are visible on the butterflyfish, not so much on the idol. Finally, the butterflyfish feeds higher in the water column, while the idol prefers the ocean floor and reef where it feeds on sponges, coral polyps, and tunicates, and other tasty reef treats. The elongated snout is helpful for probing reef crevices for snacks. And while they are much sought after for the home aquarium, they do not tolerate captivity well and are best left in their natural habitat. Remember Gill from the movie "Finding Nemo"? He was a Moorish Idol, and you might recall that his primary goal in life was to escape the tank.
Take a dash of daring, add a large pinch of stealth, then sprinkle in a bit of camouflage and what do you get? The small, but menacing Cookiecutter shark, so named for their dining technique of twisting out neat, circular plugs of flesh from the sides of their prey, much like a cookie or biscuit cutter. Isistius brasiliensis, or the cigar shark as it is also known, is an ambush predator employing a "hit and run" technique. During the day these small (17 to 22 inches), chocolate-colored sharks rest in the deep ocean, up to a couple of miles deep. At night, they ascend towards the surface. Traveling alone, or sometimes in schools, the sharks use a bit of smoke and mirrors to confuse their potential "meals." The underside of the cookiecutter emits light, allowing them to blend in with the lighter ocean surface. This makes the darker collar-like stripe around their necks stand out. Researchers infer that this stripe acts as a lure, drawing fish or marine mammals closer. Then, with a sneaky and fast dash, they bore into their prey, holding on with fleshy, sucker-like lips, and quickly twisting out a meal of flesh. Then off they flee, quick as can be. Cookiecutter bites have been documented on whales, seals, dolphins, sharks and fish. Rubber seals and coatings on Navy submarines have had to replaced due to cookiecutter chomps. In 2009, the first cookiecutter attack on a human was documented, right here in Hawaii. A 61 year-old long distance swimmer was attempting a night-time swim across the Alenuihaha Channel from Hawaii to Maui, when he felt a sharp pin prick on his lower chest. With a yelp, he swam over to the rescue boat that accompanied him, but before he could get out of the water the cookicutter managed a second bite, twisting out a plug from his calf. One skin graft and nine months later, the wound was healed. From the shark's point of view, it just want cookie, it eat cookie, "Om nom nom nom." |
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