What do you call a cat-sized, venomous, egg-laying semi-aquatic mammal with the bills of a duck, the tail of a beaver, and the feet of otters? When European naturalists first encountered the platypus, they thought that it was an elaborate conspiracy against science. All oddities aside, platypuses are ones of the only mammals that are able to use electroreception (the only other one is the echidna, or spiny anteater). The platypus has the most sensitive sense of electroreception out of all the mammals, and the receptors are located in their bills. They swim in a characteristic side-to-side motion because they are able to determine the direction of any electrical source (this, of course, works better in water). Electroreceptors in the bill are coupled with mechanoreceptors to perceive both electric signals and tactile ones. Tiny pressure pulses are detected by the bill, which direct the platypus to its prey. To feed, the platypus will dive to the bottom of the stream and dig with its bill. When tiny electrical signals are detected by the muscular contractions of organisms are detected, it will then close in on its prey. Experiments with robot shrimps sending out electrical signals have also triggered this response. These mammals are unique in that it feed by neither sight nor smell. They also possess spurs in their hind legs that inject a venom causing tremendous pain to mammals as big as humans. They also store food in their cheeks while preying, similar to squirrels. These mammals make centaurs and unicorns look normal.
http://www.animalcorner.co.uk/venanimals/ven_mammalsPlat.html
Posted by Michael Shi
Its remarkable how nature has allowed the evolution of creatures as peculiar as the platypus. Do you know which species is the ancestor of the platypus or as research been done as to see which species is? Perhaps that question will shed some light on how the platypus came to be. But I have always been curious why platypus is the only mammal that lays eggs. If you think about it, out of the millions of mammal species out there, there is only one known species that lays eggs – that is pretty incredible.
ReplyDeletePosted by James Lin
Hi Michael,
ReplyDeleteNice post! I wonder where did these platypus get all these traits from? What sort of aniaml did they evolve from? When did this happen? Are their bills that big to support their electrorecptors? Sorry for all the questions but this is just very interesting.
Posted by Whitney Huynh
Good post! My question is why is the way in which they swim related to their electroreceptive sense? Does it help with the location of electrical signals in that it allows them to triangulate the source?
ReplyDeletePosted by Michael Thomas
HOW NEAT IS THAT!!!! I can't believe that such a nifty creature is out there!
ReplyDeleteI wonder if some of their other senses (such as sight & smell, which they don't use to hunt) are noticeably weak as a result of their strong electroreceptor abilities? Also, do they use these receptors for anything other than hunting- do they use them to send signals to one another or for attracting mates, defending territory, etc?
-Johanna Brophy
I did not know that platypus were venomous. How is this possible? Do they secrete something through their skin? It is pretty funny that scientists thought that this species was created as a conspiracy. I think this is how myths are created. You cannot understand what makes some thing work so you make up magic or other means of explaining away the question. It is really interesting how receptors could be so sensitive to electrical currents that it could find food even under mud and plants! Very cool!
ReplyDeletePosted by Caroline Adams
O, the platypus, the animal of nature who seemed to be thrown together from other animals. I remember reading a children's book when I was little about how the platypus came to be. It had to do with an animal who would see other animal traits (duck bill, beaver tail, etc.) and ask to have that trait out of jealousy. In the end, it looks like a platypus, deemed a freak of nature. I guess the story was a moral message about the dangers of jealousy and appreciating what you have and how you look. But I digress. I did know they have poisenous barbs on their hind legs, though I believe this is only in the males. This of course has caused problems for people who want to own them as 'pets.' Still, I do find their method of hunting prey interesting.
ReplyDeletePosted by Austin Gray
Platypus define the laws of evolution in my mind. They are a "work of art" in the natural world. I did not know they produced electricity through their bill, but it does make sense.
ReplyDeleteWhat sparked your interest into researching these animals? I feel not that many people know about platypuses, but should.
Posted by: Em Arsenault
The platypus is such a cool animal. I have learned about a lot of fish using electric signals to communicate. Along with detecting prey several fish give off electric signals to communicate their size and establish dominance. These fish also use electric signals to find females of their species. I wonder besides from finding prey, how many different implications electroreception in platypuses there are.
ReplyDeletePosted by Nick Gast
Since the platypus spends a majority of its life in the water, it makes sense that they have developed a sensory system that works well in their environment. Whereas many mammals rely on their sense of smell for prey and mating among other things, relying on olfaction would not be very helpful for this aquatic mammal. Sharks, for example, have electroreceptors that work in their favor in a similar fashion, and studies have been conducted to prove they rely on this sense over others. I wonder if this is the case with the platypus?
ReplyDeletePosted by Sara Corey
Thanks for all the responses! Their other senses aren't weak because of their special preying mechanisms, but because underwater, they simply close their eyes and the sense of smell (chemical receptors) isn't being used. I remember reading about the hammerhead shark's electroreception and these animals are similar in that they have both evolved physiological traits to help them prey in conjunction with the adaptation of electrorepceptors. Platypuses are cool because they're mammals like us!
ReplyDeletePosted by Michael Shi
I always found platypus to be such amazing creatures, as they featured so many features from different animal species. It was always the animal I found to bind together all species as one. What I mean by that is, the platypus is proof that there were ancestors that hold birds, mammals, reptiles, etc. together.
ReplyDeletePosted by Andy Zou