As I was hiking out to Ka'ena Point this morning for the The Sanctuary Ocean Humpback Whale Count, I came across this rough rider in one of the tidepools. It's ha 'uke 'uke, a.k.a. helmet or shingle urchin. Unlike their sharp and spiky brethren, this urchin's spines are modified into flattened shingles or tiles that create a beautiful, if briny mosaic, nicely accented by a "skirt" of flattened spines. The skirt spines are moveable, and underneath are lots and lots of tube feet. These features combine to give them the ability to hang tight in the full-contact wave impact zone where they forage for coralline algae (Porolithon), encrusting, rock-like algae that continue the reef building when corals reach sea level, and become to fragile to handle the pounding surf. Ha 'uke 'uke can get baseball-sized, and their yellow roe is considered onolicious to Hawaiians past and present.
4 Comments
Birds of a feather flock together. And therein lies the problem for the koloa maoli, Anas wyvilliana. This endemic duck is endangered due to several factors, one of which is hybridization with feral mallards. Basically, the genes of the mallard are infiltrating the genes of the Hawaiian duck, causing "genetic extinction." To complicate the situation further, the hybrids are tough to distinguish from the real deal, making it hard to determine true population sizes and ranges. There is believed to be about 2,200 koloa maoli, with the majority on Kaua'i. Once abundant on all the major islands with the exception of Lana'i, by 1960's they were extirpated from all but Kaua'i. Captive breeding and release programs have brought them back to many islands, though those on Oahu are most likely hybrids. Both the male and female koloa maoli are mottled brown, and look a lot like female mallards. Males are a bit larger and a bit darker than the females, and have a greenish bill; females tend to be lighter in color, particularly on the head, and their bill color is more on the orangish side. They are denizens of wetlands, where they dabble the day away in search of aquatic invertebrates, molluscs, algae, small fish, and the like. Nesting occurs in dense vegetation (making them vulnerable to predation from mongooses, feral cats, and rats), primarily during the spring. Two to ten eggs are laid, and if we are lucky ducks, we'll have another clutch of Hawaiian ducks to grace our skies and waters.
This one is truly taking cover - in more ways than one. The collector sea urchin, Tripneustes gratilla, known locally as hawa'e maoli, makes a fashion statement by covering its spines with limu, bits of shell, or other marine debris. This masking, or covering behavior is not fully understood but may be a means of protection from the rolling abrasion of wave action, or perhaps the harmful affects of UV light. Native to Hawaiian waters as well as the Indo-Pacific and the Red Sea, Tripneustes gratilla is found in shallow water down to about thirty meters, and can get to about five inches in test diameter. These guys are constant grazers, munching primarily on algae throughout the day and night. Good thing because these urchins have been recruited for an important job: taking the cover off of the corals in Kane'ohe Bay. Several invasive algae, including those in the genus Kappaphycus and Eucheuma denticulatum are blanketing the corals in a smothering embrace. Back in the 1970's, Kappaphycus species were intentionally introduced to bay for research and cultivation; these species produce kappa-carrageenan, which can be extracted and used in the food industry. Though the cultivation efforts were not successful, the algae was. As the seaweed spread, marching northward in the bay, efforts were made to remove it. Enter the Super Sucker, a marine vacuum used to hover up the alien goo. While thousands of pounds of algae were removed, it rebounded quickly. And that's where Tripneustes gratilla comes in. Researchers at the Anuenue Fisheries Research Center on Sand Island developed techniques to breed the sea urchins, 100,000 of which were placed on the reef to do what they do best: eat the algae that is left behind. And eat they do. According to Dr. Eric Conklin, the Nature Conservancy’s Hawai‘i marine science director: “On reefs where we have placed the urchins, algae re-growth after a year is about five percent....On reefs without urchins, algae can re-grow within six months.” The Conservancy, in tandem with the State Division of Aquatic Resources, plan on releasing 200,000 urchins in 2014. ʻAi ā manō!! Hailing from China, Korea, and Japan, the oriental flower beetle, Proteatia orientalis, is a hefty beetle, about the size of my upper thumb. Its attractive bronzy metallic sheen is splotched with white markings, and gives a hint that it is in the family of Scarab beetles, many of which sport metallic colors. It also claims membership in the subfamily Cetoniinae, also known as the flower chafers, a group of diurnal beetles that feed on nectar, pollen, sap, and some, like are guy here, on damaged fruit. On Guam, where it is widespread, it has been known to feed on the flowers of papaya, coconut, betel nut, mango and corn, and may damage the flowers of these trees, resulting in fewer fruit. Proteatia orientalis has been known on Oahu since 2002, and has since been identified on Maui, and just recently on the Big Island. Eggs are laid in the soil, where the grub, or larvae hatch and then pupate; as with all beetles, metamorphosis is complete, whereas true bugs undergo incomplete metamorphosis. The oriental flower beetle can be confused with the coconut rhinoceros beetle, Oryctes rhinoceros, a major pest of coconut palms that was first seen in Honolulu in December of 2013.
|
welcomes you to visit with the all the wonderful flora and fauna that we share this lovely aina with. Categories
All
Archives
October 2014
|