The day octopus is found in shallow waters to depths of around 150 feet, and as its name suggests, they are diurnal. The lifespan is very short, around one to one and a half years. Reproduction occurs just once at the end of their lives. Females lay hundreds of thousands of eggs, attaching them to the substrate in the lair and tending them with care, including fanning the eggs to help oxygenate them. She does not leave the eggs to feed, and eventually dies, becoming nourishment for her young upon hatching.
This is a video clip of a heʻe that I video while at the fish pond with Paepae o Heʻeia. This is a remarkable creature, this day octopus, or he'e mauli. Just marvel at the oddly beautiful body. They're cephalopod molluscs, cephalopod meaning head-foot, which pretty much sums it up the design plan. Since they have no shell for protection, he'e have developed an extensive toolbox of defenses to help them evade predators such as monk seals, sharks, and humans. Lacking an internal skeleton, they are able to squeeze into small places and hide. Rapid getaways can be accomplished by taking in water through the mantle and forcing it out of the siphon. They have chromatophores in their skin that allows them to quickly change color and they use muscles to transform their skin texture, camouflaging into their surroundings magnificently. And when things really get tough, there is always the squirt of ink, ejected from an ink sac in the mantle. The ink can work in several ways. It may impede predators from smelling, and thereby locating, the octopus. It also can act as a screen, or be used to create a false shape, acting as a decoy as the true octopus flees. As hunters themselves, they are just as masterful. Well developed eyes, sense receptors on their arms, and chemoreceptors on their suction cups help the octopus to see, feel, and taste for its food, which include crustaceans, fish, and molluscs. Swooping down on their prey, they enfold them in their web and hold them tight with their suckers. They then inject them with a paralyzing venom and digestive enzymes which help break down the body of the prey. The he'e mauli has a sharp beak which it uses to tear the flesh.
The day octopus is found in shallow waters to depths of around 150 feet, and as its name suggests, they are diurnal. The lifespan is very short, around one to one and a half years. Reproduction occurs just once at the end of their lives. Females lay hundreds of thousands of eggs, attaching them to the substrate in the lair and tending them with care, including fanning the eggs to help oxygenate them. She does not leave the eggs to feed, and eventually dies, becoming nourishment for her young upon hatching.
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Now you see them, now you don't. Ghost crabs, a.k.a. sand crabs, or 'ohiki, belong to the genus Ocypode, which means fast footed, and that they are. A day at the beach wouldn't be the same without them; all that digging and chasing and scuttling is fun to watch and provides a pleasant diversion after a cool dip. We have two species here: the pallid ghost crab and the horn-eyed ghost crab, and both species may occupy the same beach. The horn-eyed prefers to dig its burrows closer to the shoreline, and makes pyramid-shaped piles of sand when excavating. They are the larger of the two species, getting up to three inches across the carapace, and as the name suggests, they have horny stalks on top of the eye. The pallid ghost crab is a messier excavator, digging higher up on the beach and fanning out the sand around their burrows. They are typically an inch across the shell. Ghost crabs have ten legs to help them do all the digging and running, and of course, feeding. These nocturnal predators and scavengers dine on seaweeds, portuguese man-of-war, mole crabs, detritus; pretty much any debris that's edible. They're like a beach clean-up crew. Breathing is done with gills, so they can take a dunking, and they are able to run around on land as long as the gills are kept moist.
An interesting feature of these crustaceans is their coloration. Ghost crabs on white beaches are white, and on black beaches, they're black. Scientists have experimented with these crabs by placing the white crabs on black sand and black crabs on white sand. And yes, indeed, they were able to change their coloration over a period of time. Anything to help you from seeing a ghost.
The beautiful milo (Thespesia populnea) has a lot going for it, but let me start by highlighting its often overlooked flowers: they are like sunrise and sunset on a tree. They last only a day, beginning as a buttery yellow flower with a red center, then the flower turns reddish orange with the setting sun. The blossoms then fall to the ground, and brownish-grey seed capsules form. This daily transformation helps me overlook the fact that milos are constantly shedding their leaves and seed capsules; a bit messy, but well worth the bother. The emerald green leaves are shiny and shaped like a heart. Milos do well in a variety of soils, and are found from coast to elevations of about one thousand feet. They can take the tough stuff, like wind and salt spray as long as they get a good dose of sun; there are milos on Kaho'olawe making it work! Milos are in the mallow, or Malvaceae family, as are its cousins: hau, 'ilima, and ma'o. It is likely an indigenous plant, but was also brought by the early Polynesians in their canoes. It can grow to about thirty feet or more, and its wood was often used for making vessels, such as poi bowls, ʻumeke ʻai. It has a beautiful grain, did not flavor the food placed in the bowl, and was relatively insect-free, making it a good choice. It was also used for cordage and canoe hulls, and the fruit was used in making a yellow-green dye. A hearty tree with blossoms of sun and useful to boot! I have read that milo trees surrounded the home of King Kamehameha I in Waikiki, and that beautiful image seems just right.
They're beautiful, they don't sting, and they eat mosquitoes - what more could you want in an insect? This is Hawaii's endemic pinao, the Giant Hawaiian Dragonfly, Anax strenuus. Found at higher elevations, this skilled hunter often scouts his way around ponds, marshes, and other aquatic habitats in search of insects, zipping around at impressive speeds and with great maneuverability. They can hover, move forward, backward, up, down, and execute sharp turns with the greatest of ease. This is due in part to the wings of the dragonfly; they can move their fore-wings and hind-wings independently, unlike bees and butterflies that flap their wings in unison. Eggs are laid in or near the water by the female, who uses her abdomen like a needle to cut into plant tissue to deposit her eggs. Such behavior of this and related dragonflies earned them the name "darners." The eggs hatch into larvae known as nymphs, or naiads, and live aquatic, carnivorous lives. How to Tell Damsels From Dragons
If you're not sure of the difference between dragonflies and damselflies, here are a few easy tips to get you started. The first thing to do is notice their flight. If they are energetic flyers, it's probably a dragonfly. Damselflies tend to perch more often and are weaker fliers. Next, observe their wing position when they are at rest. Dragonflies hold their wings out to the side like an airplane, while damselflies will hold their wings vertically, pressed together above their thorax and pointing up and back. You'll also observe that the wings or the damselfly are smaller than the dragonfly's, and are similar in shape. The dragonfly's fore and hind-wings are shape differently. The eyes offer another helpful clue: dragonfly eyes often meet in the middle; the damselfly's eyes are set apart father to the sides of the head. No matter which, both members of the Odonata Order are a delight to watch and deserve our kokua: many are endangered due to loss or degradation of habitat, and the nymphs are often preyed upon by invasive fish, frogs, and invertebrates. The very first fish I laid eyes on in Hawaii was the reef triggerfish, the humuhumunukunukuapua'a, or Rhinecanthus rectangulus. One look at him and I knew I was going to love this place. I think it was the blue lipstick at the end of the long, piggish snout that really won my heart, but the whole modern art look they've got going is striking. The nukunuku-ä-pua‘a part of the Hawaiian name indeed translates to "snout like a pig," and it is said that they will grunt when chased or handled, though I myself have not heard them do this. They dine on algae and marine worms, but with powerful jaws like that, you can see that they are well adapted to feeding on the crunchier fare of the ocean floor: crustaceans, sea urchins, and brittle stars. The eyes are set way back on the head, perhaps making it easier for them have a go at sea urchins, and they can also move their eyes independently. They have an interesting way of swimming: the humuhumu ripple their dorsal and anal fins (see video below), which gives them good maneuverability, including the ability to move forward and backward. The common name of triggerfish name comes from a trigger-shaped dorsal spine on their backs, and their ability to "lock and load." The reef triggerfish actually has two spines, the smaller of which is used to lock the "trigger" spine upright when it has wedged itself into a hole or crevice in self-defense, making it difficult to pull them out. They are also capable of muting their colors and will often do so while sleeping. This solitary fish knows how to lie low, but it won't stop us from admiring their bursts of color and energy that make snorkeling here so much fun. Of the eight gecko species here in Hawaii, the house gecko, Hemidactylus frenatus, is probably the one you are most familiar with. We've all seen their gravity defying jaunts across the ceiling or watched them chasing down cockroaches and moths. Yet we may not realize just how remarkable these lizards are. For starters, they can vocalize, chirping out the familiar tuk-tuk-tuk-tuk-tuk at night, and yet vocalizations are unusual for members of the Order Squamata, the group that includes all lizards and snakes. Secondly, they'll kill it in a staring contest as their eyelids are fixed; no blinking for this guy. Instead, they clean their eyes with their tongues. Their eyes are quite beautiful, with a vertical pupil that resembles a keyhole. They are also capable of caudal autotomy, the ability to lose part of their tail, as a defense mechanism. The severed appendage will continue to wriggle, further confusing the would-be predator.
And if that's not enough, consider their extraordinary toe pads. They are covered with small hairs called setae, which are mere micrometers in diameter and spatula-shaped at their ends. This allows for a great deal of surface area contact, and generates van der Waals forces, the same forces you learned about in Chemistry class that contribute to molecular bonding. This is what allows the gecko to do its spider-man thing. Scientists around the world are working on creating a synthetic version of the gecko toe pad. "Gecko tape," as it is often referred to, is still in its early phase of development, but could one day be used to hang televisions on walls, create fumble-free football gloves, or replace sutures in surgery. Others envision it on the boots of astronauts, enabling them to walk on the space craft unencumbered by harnesses. That little friend hanging around your porch light could one day have us literally climbing the walls.
If you're thinking that this fantastic palm would make great shelter from the rain, you'd be spot on. The Hawaiian name for this member of the Pritchardia genus is loulu, meaning "umbrella." There are twenty or so species of these fan palms that are endemic to the Hawaiian islands, and they vary widely in habitat and height. Each island has at least one species that is theirs alone. This one is loulu hiwa (Pritchardia martii) which is endemic to Oahu, preferring mesic to wet elevations of the Ko'olau Mountains. Though slow growing, it can reach heights of 30 feet or more at maturity. Like all palms, the inflorescence, or cluster of flowers off a main stalk, splits out of a protective covering at the base of a leaf. Bees love the white flowers, which when pollinated will develop into fruit called hāwane or wāhane. They darken when ripe (hiwa) and are said to be eaten by early Hawaiians. Unfortunately, rats and other animals enjoy the fruits as well, but if you are able to get them, they are easy to germinate. Grow this palm and you'll be a fan! |
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