Scientists Cryo-Freeze Coral Reef 130
An anonymous reader writes "Due to rising ocean temperatures, scientists from the United States and Australia are attempting to freeze coral eggs and sperm in cryogenic suspension so that the endangered species can be preserved. Once frozen, the species may later be grown in a lab and implanted in reefs. This could be the only way to ensure the survival of certain endangered species at The Great Barrier Reef."
Re:Coral sperm? (Score:5, Informative)
Because they are sedentary, colony-living, and gradually form massive calcified structures, there are certain respects in which their role and macrostructure resembles that of plants(the two are enormously different biologically; but both are the major structural organism of their respective environments)...
Re:Too late :( (Score:5, Informative)
The longer wavelengths of sunlight (such as red or orange) are absorbed quickly by the surrounding water, so even to the naked eye everything appears blue-green in color. The loss of color not only increases vertically through the water column, but also horizontally, so subjects further away from the camera will also appear colorless and indistinct. This effect is true even in apparently clear water, such as that found around tropical coral reefs.
Underwater photographers solve this problem by combining two techniques. The first is to get the camera as close to the photographic subject as possible, minimizing the horizontal loss of color. Wide-angle lenses allow very close focus, or macro lenses, where the subject is often only inches away from the camera. Many serious underwater photographers consider any more than about 3 ft/1 m of water between camera and subject to be unacceptable. The second technique is the use of flash to restore any color lost vertically through the water column. Fill flash, used effectively, will "paint" in any missing colors by providing full-spectrum visible light to the overall exposure.
Re:Coral sperm? (Score:0, Informative)
Corals are animals (multicellular heterotrophs) in the Phylum Cnidaria [wikipedia.org], the same group that includes jellyfish and sea anemones. They eat things. They have a mouth and gut to digest food and tentacles with stinging cells to snare prey. In addition, most modern-day reef-forming corals living in shallow water also have symbiotic algae known as zooxanthellae [wikipedia.org]. In corals these are most often single-celled creatures called dinoflagellates [wikipedia.org]. As separate creatures dinoflagellates are quite diverse and can either be heterotrophs (eat things) photoautotrophs (photosynthetic) or both at the same time (mixotrophs), but the zooxanthellate ones in corals are invariably the photosynthetic types. Dinoflagellates are not "plants" in the traditional sense of the word (multicellular photosynthetic land plants), but are considered protists [wikipedia.org], a category that includes mostly single-celled creatures with a nucleus and other eukaryotic [wikipedia.org] structures. To make things stranger, a lot of dinoflagellates are photosynthetic because they themselves contain recognizable symbiotic algae or their remnants in the form of chloroplasts. But if you wanted to generalize, it's kind of like you have an animal (corals) with photosynthetic "plants" (zooxanthellae/dinoflagellates) that live inside them, which themselves have symbiotic photosynthetic structures inside of them.
Re:IANACS, so could someone explain? (Score:5, Informative)
No. In a number of ways. Firstly, corals and the group to which they belong (Phylum Cnidaria) are indeed very ancient animals, and are found as fossils all the way back to the latest Precambrian, probably about 600 million years ago or so. There are older fossils, but they are single-celled creatures. Those go back at least 3 billion years or more. So, oldest animals, maybe. Oldest lifeforms, not by a long shot.
Modern day corals are a bit of an oddity because they are very young. They date from the middle Triassic Period and younger (~230 million years ago). There were many types of reef-building corals in the earlier Paleozoic era (545-250 million years ago), but they *all* became extinct during the biggest mass extinction at the boundary between the Permian and Triassic periods. For ~20 million years there were no coral reefs in the world at all until the modern scleractinian corals evolved. It is thought that these originated from mostly soft-bodied sea-anemone-like cnidarians after the original Paleozoic corals were wiped out, and there are a few fossils known of similar creatures from the Paleozoic, but they were a minor group until the others became extinct.
So, you are right about the implication that corals can survive some pretty tough stuff. On the other hand they have been entirely wiped out by major changes and it took evolution of an entirely new group before coral reefs became reestablished after about 20 million years or so. It's more like they "started over" from non-reef-building forms than survived that event.
The modern-day corals are mainly endangered because of changes in ocean chemistry related to increasing CO2 content in the atmosphere and the effect this has on their ability to grow skeletons. This is quite bad for them. Extinction kind of bad. Probably not enough to cause all of them to become extinct everywhere, but pretty likely to decimate them if it keeps going.