Leviathan Mermaids (and other Merfolk)

question what do the bottom halves of a leviathan mermaid look like, a whale and if a whale which species

Oldman40k2003 wrote:

The other problem is their ability to see infrared light. It seems unlikely to me that a sea creature would develop/evolve such an ability, for two reasons. Firstly, water is a very good absorber of infrared light and so the distance infrared light travels through water is very limited, meaning that prey a very short distance away from the Yabla'un would be invisible to its sight. The second problem I have with it is that most sea creatures are cold blooded, which means that they are very close to background temperature and don't emit much more in the way of infrared rays than the water surrounding them does.

Erm... you are aware that many creatures found in the deepest depths of the sea actually DO see and/or emit infrared light through bioluminescence? O.o

In fact, it is far, far more common among creatures living within and beneath the Abyssopelagic zone than sonar/echolocation abilities are. Creatures such as the Black Swallower and species of deep-sea Anglerfish are entirely dependant their prey's ability to perceive infrared light, and/or their own ability to do the same.

And they aren't just exceptional cases, it is pretty much the standard throughout the entire region, to be able to see infrared light to some degree or another.

Edit: For those who are interested in such things, I highly recommend the fantastic BBC documentary series The Blue Planet and also Planet Earth, which is produced by the same team that did The Blue Planet. Planet Earth has incredible production values and is narrated by Sigourney Weaver (for the American version).

I bought both series on DVD a while back (they can be pretty pricey, unfortunately), and they are well worth the money for anyone who is interested in oceanic life.

https://www.youtube.com/watch?v=W9Er4dpUfrM is a clip from the second (I think) episode of Blue Planet, which is the Deep Sea episode. You will definitely see what I'm talking about, in regards to infrared light at extreme depths of the ocean.