If biology’s most essential molecules had a popularity contest, adenosine triphosphate (ATP) would be up near the top. It is a highly conserved, critical molecule across intracellular and extracellular activities. You learn about many of those activities in Biology 101. Remember mitochondria, the “powerhouse of the cell”? That power comes in the form of ATP.
But what happens when ATP finds its way into the outside world where it doesn’t naturally occur? On dry land, the answer to that question appears to be “not much.” Underwater, however, ATP leaking out of living creatures and into the water column can profoundly affect behavior. For instance, in marine decapods like spiny lobsters (Panuliris sp.), ATP can serve as the molecular equivalent of a dinner bell.
I first learned about this phenomenon while wrapping up my undergraduate studies in Ecology, Behavior, and Evolution at UCLA. My professor, Richard Zimmer, spent part of the 80s and 90s exploring what roles ATP might play in mediating feeding activity in California spiny lobsters (Panulirus interrupts). Sometime earlier, another researcher named William E.S. Carr demonstrated that a relative of Panuliris interruptus called Panulirus argus possessed olfactory chemoreceptors that could be stimulated by ATP. He stopped short, however, of exploring the role those receptors might play in the overall behavior of the lobster.
Professor Zimmer took that information and picked up where Carr’s work left off. Through a series of meticulous experiments involving P. interruptus, Zimmer determined that those receptors were related to hunting and feeding. Specifically, ATP was a potent chemical stimulant of foraging behavior.
ATP Standing Out From the Crowd
So what is so special about ATP, and why is it such an effective stimulant? For one, Zimmer proposed that ATP was a potent feeding signal because of its high signal-to-noise ratio in the environment. The marine environment is a swirling soup of olfactory noise. Animals like lobsters spend their lives in the molecular equivalent of a loud house party, but much like you can pick out the shout of your best friend from across a noisy, crowded room, a lobster can quickly distinguish specific unusual signals like ATP. This is because ATP does not naturally occur in the marine environmental milieu. If it’s detected there, it stands out like a sore thumb.
ATP is also a reliable indicator of live (and probably injured) prey. When animals die, and their tissues start to decay, the ATP inside is rapidly converted to adenine monophosphate (AMP). So, if a predator detects ATP, it’s almost certainly from a fresh source.
So there you have it. ATP is more than just the “universal energy currency” you learn about in Biology 101. It’s also a potent environmental mediator of foraging activity in at least one kind of marine carnivore.
References and Further Reading
- Fuzessery, Z. M., Carr, W. E., & Ache, B. W. (1978). Antennular chemosensitivity in the spiny lobster, Panulirus argus: studies of taurine sensitive receptors. The Biological Bulletin, 154(2), 226-240. (PDF)
- Johnson, B. R., & Ache, B. W. (1978). Antennular chemosensitivity in the spiny lobster, Panulirus argus: amino acids as feeding stimuli. Marine & Freshwater Behaviour & Phy, 5(2), 145-157.
- Reeder, P. B., & Ache, B. W. (1980). Chemotaxis in the Florida spiny lobster, Panulirus argus. Animal Behaviour, 28(3), 831-839. (PDF)
- Schmidt, M., & Derby, C. D. (2005). Non-olfactory chemoreceptors in asymmetric setae activate antennular grooming behavior in the Caribbean spiny lobster Panulirus argus. Journal of Experimental Biology, 208(2), 233-248. (PDF)
- Zimmer-Faust, R. K. (1993). ATP: A potential prey attractant evoking carnivory. Limnology and oceanography, 38(6), 1271-1275. (PDF)
- Zimmer-Faust, R. K., Gleeson, R. A., & Carr, W. E. (1988). The behavioral response of spiny lobsters to ATP: evidence for mediation by P2-like chemosensory receptors. The Biological Bulletin, 175(1), 167-174. (PDF)
- Zimmer-Faust, R. K. (1987). Crustacean chemical perception: towards a theory on optimal chemoreception. The Biological Bulletin, 172(1), 10-29. (PDF)
- Zimmer-Faust, R. K., Michel, W. C., Tyre, J. E., & Case, J. F. (1984). Chemical induction of feeding in California spiny lobster, Panulirus interruptus (Randall). Journal of chemical ecology, 10(6), 957-971.
- Zimmer-Faust, R. K., & Case, J. F. (1983). A proposed dual role of odor in foraging by the California spiny lobster, Panulirus interruptus (Randall). The Biological Bulletin, 164(2), 341-353. (PDF)