Absolutely necessary for living in space.
Electroreception is the ability to sense electrical fields in animals. Humans don’t really have this without the use of a fork in a wall socket (please don't try this). Sharks famously do, as do rays, electric eels some other Gymnotiformes and Monotremes (primitive egg laying mammals: platypus and echidnas) recently it has been discovered in dolphins. Sharks and other fish use the Ampullae of Lorenzini, gel filled pores derived from their lateral line. Monotremes use free nerve endings on their snout. Dolphins use what remains of their whiskers, left over from their terrestrial days.
Soon to come again…
It has been suspected that Guyana dolphins (Sotalia guianensis) have the ability to sense electrical fields because they hunt on the seafloor where sediment can cloud the water, obscuring sight and echolocation. Additionally they have unusually large vibrissal cysts (modified whisker clusters) on their snout. If these were useless they would have withered in a similar fashion to what’s left of your tail. German researchers dissected vibrissal cysts in a dead (of natural causes, so they didn’t piss off PETA and Travis Ryan) Guyana dolphin. They found that the vibrissal cysts were not only surrounded by a capillary mesh instead of the blood sinus found in the whiskers of normal mammals, they also had a large amount of nerve endings: about 300 (in other mammals the number is about 80-200)
Closeup of vibrissal cysts
They also trained a captive dolphin to hold its head between two electrodes and react if a current passed through them. They found that the dolphin could react to stimuli of 4.6 µV cm−1 (much smaller to the field generated by a small fish)
This is a prime example of convergent evolution. This sense has been evolved separately at least 3 times by different groups of animals (fish, Monotremes and dolphins), each using different anatomical structures to accomplish the same task, like birds, bats and insects evolving flight separately. This study was published July 2011 and it appears that electroreception in dolphins and other cetaceans has not been studied further than the Guyana dolphins; perhaps your good old fashioned bottlenose dolphins (Tursiops truncatus) have this sense? How does this affect us? Not at all.
If you have any questions please put them in the comment and ill try to answer them the best I can. Hope you learned something.
-Judge Shredd
Get cited (you probobally will not be able to read the article without a liscence):
It has been suspected that Guyana dolphins (Sotalia guianensis) have the ability to sense electrical fields because they hunt on the seafloor where sediment can cloud the water, obscuring sight and echolocation. Additionally they have unusually large vibrissal cysts (modified whisker clusters) on their snout. If these were useless they would have withered in a similar fashion to what’s left of your tail. German researchers dissected vibrissal cysts in a dead (of natural causes, so they didn’t piss off PETA and Travis Ryan) Guyana dolphin. They found that the vibrissal cysts were not only surrounded by a capillary mesh instead of the blood sinus found in the whiskers of normal mammals, they also had a large amount of nerve endings: about 300 (in other mammals the number is about 80-200)
Closeup of vibrissal cysts
They also trained a captive dolphin to hold its head between two electrodes and react if a current passed through them. They found that the dolphin could react to stimuli of 4.6 µV cm−1 (much smaller to the field generated by a small fish)
This is a prime example of convergent evolution. This sense has been evolved separately at least 3 times by different groups of animals (fish, Monotremes and dolphins), each using different anatomical structures to accomplish the same task, like birds, bats and insects evolving flight separately. This study was published July 2011 and it appears that electroreception in dolphins and other cetaceans has not been studied further than the Guyana dolphins; perhaps your good old fashioned bottlenose dolphins (Tursiops truncatus) have this sense? How does this affect us? Not at all.
If you have any questions please put them in the comment and ill try to answer them the best I can. Hope you learned something.
-Judge Shredd
Get cited (you probobally will not be able to read the article without a liscence):
Czech-Damal, N. U., Liebschner, A., Miersch, L., Klauer, G., Hanke, F. D., Marshall, C., et al. (2011). Electroreception in the Guiana dolphin (Sotalia guianensis) . Proceedings of the Royal Society of Biological Sciences , doi:10.1098/rspb.2011.1127.
Dang, three days in a row of new writers! More on the way, too... Anyhow, The Judge is pretty smart about science and whatnot, but don't worry, he likes metal, too. We look forward to his future contributions, whether they be based in biology or crippling shred. HAIL.
- Cobras
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