Marine fish may be biochemically constrained from inhabiting the deepest ocean depths
Abstract
Fish appear to be absent from the ocean's greatest depths, the trenches from 8,400-11,000 m. The reason is unknown, but hydrostatic pressure is suspected. We propose that the answer is the need for high levels of trimethylamine oxide (TMAO, common in many marine animals), a potent stabilizer capable of counteracting the destabilization of proteins by pressure. TMAO is known to increase with depth in bony fishes (teleosts) down to 4,900 m. By capturing the world's second-deepest known fish, the hadal snailfish Notoliparis kermadecensis from 7,000 m, we find that they have the highest recorded TMAO contents, which, moreover, yield an extrapolated maximum for fish at about 8,200 m. This is previously unidentified evidence that biochemistry may constrain depth for a large taxonomic group.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- March 2014
- DOI:
- 10.1073/pnas.1322003111
- Bibcode:
- 2014PNAS..111.4461Y