Hawaiian Marine Life Profiles: Invertebrates
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Hawaiian Spiny Lobster
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|Once a plentiful culinary delight, the Hawaiian spiny lobster (ula, ula poni) has become a treat reserved mainly for folks willing and able to go out and catch one by hand. Even then, strict rules must be followed. Current regulations forbid the taking of females year round, set a minimum size for taking males at 3 and 1/4 inches and mandate that no lobsters may be taken during the major reproductive season of May through August. Spearing is prohibited.
Department of Land and Natural Resources figures show that only about 3,600 animals were caught commercially during each of the past two years, down from roughly 5,900 animals harvested in 2005. Compare these figures to commercial takes averaging about one million animals per year during the period of 1984 to 1990.
Concurrent with the federally mandated shut down of the commercial lobster fishery in the Northwestern Hawaiian Islands in 2000 due to declining populations, the appearance of emaciated, dead or dying Hawaiian monk seal pups illustrated the impact that the depletion of one species can have on another. Critically endangered Hawaiian monk seals rely on spiny lobsters as a food source. When supplies diminish, the young suffer.
Considering its boom and bust history, the Hawaiian spiny lobster could qualify to be the poster species for better conservation of ocean resources. Its story deserves to be remembered when the human species debates just how important it is to respect and protect the delicate balance of life in the ocean.
Aside from their culinary appeal, Hawaiian spiny lobsters are necessary reef scavengers and predators. During the day they hide in caves or under ledges, then emerge at night to hunt slow-moving mollusks, crustaceans and echinoderms. Eating whatever's available, including dead fish, they help to keep our reefs clean.
Three species of spiny lobsters inhabit Hawaiian waters, but only two have commercial value. The banded spiny lobster or ula poni has a purplish or reddish brown carapace or shell and black, blue or almost purple legs. The tufted spiny lobster sports a greenish carapace with yellow/orange markings. Yellow and white stripes run lengthwise on its legs. The third species, the long-handed spiny lobster is uncommon and not sought commercially. It has a red carapace with yellow markings.
Spiny lobsters are so named because they have spines pointing forward on their carapaces and antennae. One pair of antennae is predominantly larger. None of Hawaii's spiny lobsters have the large pincers or claws associated with the Maine lobster, although the long-handed spiny lobster does have a slightly larger "false claw." Banded and tufted spiny lobsters co-exist well together and both species may be caught in the same traps. Sizes of both rarely exceed 16 inches.
Spawning for Hawaiian spiny lobsters occurs four times per year from May to August and November to December. The male spiny lobster-attracted by the female's pheromones or special chemicals-will "glue" a packet of sperm to an area near the female's reproductive opening. Each time she spawns, a female can produce up to a half million orange or reddish-colored eggs that become fertilized as they leave her body. She will hold the egg mass under her abdomen by means of her swimmerets-specialized appendages also used to aerate or fan the developing embryos. Females carrying eggs are called "berried females." Eggs hatch about a month later but almost a year will pass before the widely dispersed larvae begin to resemble lobsters.
Spiny lobsters communicate and warn intruders to stay away from their shelters by means of a grating or buzzing sound called stridulation. Like other crustaceans, they wear their skeletons on the "outside" as a shield of armor to protect their soft insides. Prior to molting or abandoning its shell, the spiny lobster produces a soft carapace or "skeleton" beneath its old one. The old shell eventually splits at the juncture of tail and body. The lobster then discards it and enlarges the soft new carapace by swelling its skin cells with water. The lobster must hide from predators while the new carapace is hardening. Once this occurs, it rids itself of excess water. The lobster now has room for further growth.
Another threat to Hawaiian spiny lobsters is the collection of colorful juveniles for home aquariums. Amateur aquarists should consider allowing this species the opportunity to grow up and reproduce in the wild. Commercial efforts to produce mass quantities of Hawaiian spiny lobsters for the marketplace are "in the works". Whether such efforts succeed or not, the Hawaiian spiny lobster needs all the help we can give it - and the first requirement is a healthy reef system. The second is careful regulation of recreational and commercial catches. Without these two elements, they cannot survive.