Meet ula-päpapa, the slipper lobsters. Looking a bit like a flattened bulldozer, these crustaceans are decapods, "ten-leggers," as are shrimp, prawns, and crabs. Their most prominent feature are two modified and flattened antennae that appear like shovels sticking out of their heads. Three species that may be seen on the reef include the scaly slipper lobster (Scyllarides squammosus), the Antarctic slipper (Parribacus antarcticus), and the hump-backed slipper (Scyllarides haani). Slipper lobsters generally lie low during the day, either blending in with their surroundings or holing up in the many crevices the reef affords. Come nightfall, they scavenge and dine on the brok da mout smorgasbord of the reef, consuming shrimp, worms, snails, urchins; some even snack upon anemones. Of course, they themselves are pretty ono. Predators include octopi, triggerfish, and groupers, as well as humans. Regulations have been established for the taking of slipper lobsters: 1) they must be of a certain size (2 3/4" tail length), 2) they may only be taken from September through April, 3) no taking of hapai "berried" females, and 4) they may not be spearfished. Their life cycle begins with the laying of eggs, which the female carries around under her body. Upon hatching, the larvae drift around for the better part of a year, eventually taking up life on the reef. Because their exoskeleton is inelastic, slippers must moult periodically to accommodate their growth. A new but soft shell forms beneath the old, and when ready to go, the exoskeleton will crack at the junction of the body and tail. With a bit of wriggling, the lobster slips out. Chee, I wen bus my slippah! This is a particularly vulnerable time for the not so crusty crustacean, and they tend to go into hiding until the shell hardens.
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On a recent excursion, I came across some dodder, a parasitic plant that is strangely beautiful and menacing at the same time. This seemingly contradictory effect is noted in some of its common names, which include devil's hair, angel hair, and strangleweed. It is known to parasitize a variety of plants, including crops such as alfalfa, clover, and flax. I had only seen it once before, cozied up to some vegetation along the Maine coast, but later learned that tropical and semitropical regions are host to more species of dodder than temperate zones. Hawaii has one species that is endemic, Cuscuta sandwichiana, locally known as kuana'oa, and one alien species, Cuscuta campestris. Kuana'oa is the official flower of Lana'i, and may be twisted and braided into beautiful lei. The seeds of dodder are capable of remaining viable for quite some time, and when conditions are right, they will germinate and root into the ground. Now the race is on, because it must quickly find a host plant. Using chemosensory clues (and perhaps other clues), it "sniffs out" it's host and with a twisting embrace, taps into its vascular system with specialized roots called haustoria that appear as little bumps on the stem. The original root of the dodder dies off, and it is now dependent on the host. Kuana'oa tend to parasitize herbaceous plants, while a similar looking but unrelated plant, Cassytha filiformis, tends to prefer woody plants. No matter which, they both know how to cling to life.
The tiger shark has certainly earned its stripes as an apex predator. With sleekness and stealth it cruises the Hawaiian waters, as well as tropical and subtropical waters around the world, making a meal of just about everything that moves and even some things that don't: jellyfish, mollusks, octopi, fish, sea birds, monk seals, dolphin, turtles, whale carcasses, and yes, even garbage has been found in their guts. This is one of the largest sharks, and though reports vary on size, it would seem an average adult shark would be about fifteen feet long. Imagine taking the tallest person you know and doubling their length, and you'd almost have their size. Mottled stripes are found along the sides of younger sharks, fading as the shark ages. Countershading provides tiger sharks with a bit of camouflage to take prey by surprise, with a darker color on the dorsal surface (back) and a lighter color on the ventral surface (belly). If you were to view the shark from below, the light underside would blend in with the lit ocean surface, and if you viewed it from above, it would blend in with the darker ocean floor. A huge wedge of a snout holds the serrated teeth that have a distinct notch (see picture below). Other characteristic features include five gill slits, and an elongated top lobe on the caudal (tail) fin. The tiger shark is one of the top three sharks species known to attack humans (the others being the great white and bull sharks). In Hawaii, there are an average of three to four shark attacks per year, according to the University of Hawaii Shark Research Program. I learned some pretty interesting things from their website. In the late nineteen-fifties to mid-seventies, there was a shark culling program in effect in Hawaii. It was believed that sharks had a high fidelity to a given territory, and that culling would mean safer waters. Over four thousand sharks were taken, and yet there was no significant change in the numbers of shark attacks.
Later, funding was sought and given to a team from the Hawaii Institute of Marine Biology to test the idea of site-attachment. Sharks were captured, tagged, measured, and implanted with a tracking device so that swimming and travel behavior could be monitored. This research indicated that the tiger sharks roamed between the islands and were not bound to one given territory. Therefore, culling would not produce the desired effect. Research continues to be conducted to gain insights about these amazing creatures. To learn more, visit: http://www.hawaii.edu/HIMB/ReefPredator/Tiger%20Shark%20Research.htm
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October 2014
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