All Animals are Aerobic..... False
It seems, once again, that life doesn't read textbooks.
A recent discovery of an organism called a loriciferan in the deepest portions of the Mediterranean Sea might be changing the way we think of animals. These small organisms resemble jellyfish, but are currently believed to be more closely related to the nematodes (round worms) and arthropods (the phylum containing the insects and crustaceans). The loriciferans from the Mediterranean sample lack mitochondria, but appear to have structures called hydrogenosomes , structures which share an evolutionary heritage with mitochondria, but are adapted for anaerobic environments.Although there are some single-celled eukaryotic organisms that live without mitochondria (the intestinal parasite Giardia lamblia is a nice example), to date it was believed that all multicellular animals were aerobic.
If this animal turns out to be truly anaerobic, then it will change where we look for new animal species on our planet, and elsewhere in the solar system. Oxygen appears to be a relatively rare gas in our solar system (it is usually bound to other elements), so the searches for life on other planets has focused mostly on bacteria. But the Mediterranean loriciferan may make us rethink that philosophy, and opens up the potential for more complex lifeforms on anaerobic worlds.
MI13 - evolution of life (chapter 27); animal evolution (chapter 30)
A recent discovery of an organism called a loriciferan in the deepest portions of the Mediterranean Sea might be changing the way we think of animals. These small organisms resemble jellyfish, but are currently believed to be more closely related to the nematodes (round worms) and arthropods (the phylum containing the insects and crustaceans). The loriciferans from the Mediterranean sample lack mitochondria, but appear to have structures called hydrogenosomes , structures which share an evolutionary heritage with mitochondria, but are adapted for anaerobic environments.Although there are some single-celled eukaryotic organisms that live without mitochondria (the intestinal parasite Giardia lamblia is a nice example), to date it was believed that all multicellular animals were aerobic.
If this animal turns out to be truly anaerobic, then it will change where we look for new animal species on our planet, and elsewhere in the solar system. Oxygen appears to be a relatively rare gas in our solar system (it is usually bound to other elements), so the searches for life on other planets has focused mostly on bacteria. But the Mediterranean loriciferan may make us rethink that philosophy, and opens up the potential for more complex lifeforms on anaerobic worlds.
Links
- Live Science article on the loriciferan discovery
- electron micrograph of a loriciferan
Textbook Links
MB10 - invertebrate evolution (chapter 28)MI13 - evolution of life (chapter 27); animal evolution (chapter 30)
Posted by Michael Windelspecht at 12 Apr 2010, 2:44 PM 
Categories: energy, animals
Tags: loriciferan mitochondria
Categories: energy, animals
Tags: loriciferan mitochondria
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