Mammal Monday: Venom, Eggs and Mammalianess

Image: http://australian-animals.net/plat.htm

 We won't see these on our African adventures but I simply couldn't resist a mammal monday in honour of these egg-laying, venomous, duck-billed, beaver-tailed, otter-footed mammals, platypuses! These little guys are really cool because they are mammals but so markedly different from other mammals.

Firstly, they lay eggs - interestingly, they are in uetro for 28 days and only spend ten days incubating externally. Chickens on the other hand have their eggs on the inside for only one day and they are on the outside for 21 so technically platypuses keep their babies inside for a pretty long time considering.
Another fascinating baby-related tidbit is that mum platypuses have mammary glands but no teats so they excrete milk through their pores (bleurgh) and there are grooves on their abdomen to catch the milk in so that the babies can subsequently lap it up. 

Image: http://www.southernfriedscience.com/?p=1287

Both males and females are born with ankle spurs but only male platypuses actually produce venom, making platypuses one of the few venomous mammals around. Apparently they produce more venom during the mating season and while the venom won't kill a human it can cause long-lasting hyperalgesia (a heightened sensitivity to pain) that persists for days or even months...nasty little buggers.

Another interesting non-mammal feature that platypuses have is that they use electroreception - this means that they can locate their prey (in part) by detecting electric fields generated by muscular contractions. They are the only mammal to do this.

All in all, these little guys really are cool. Unusual yes, but who said normal was anything special.

As always, thanks wiki.