More strange beasts from the ocean depths that you might not have seen

You have probably, like me, seen a whole load of David Attenborough documentaries about weird and wonderful sea creatures from the depths of the ocean. But here are a few that are new to me, mainly courtesy of Nerdist.com:

• Gulper Eel: one moment, it's a regular looking skinny black eel thing, the next it has balloned up into something from your worst nightmare (or possibly a muppet, depending on how your mind works), thanks to an expandable jaw. It is also known as a pelican gulper or umbrella-mouth gulper.
• Whale sharks: reasonably well-known as the largest shark in the sea (indeed, the biggest fish of any kind), but did you know that whale sharks' eyes are covered in teeth. Actually called "dermal denticles", these tiny proto-teeth are part of the whale shark's impressive battery of protective adaptations. They can also retract their eyeballs back into their sockets if need be.
• Ravioli starfish: this strange beast looks for all the world like, well, ravioli. Pillowy and pentagonal, this starfish has been know of for many years (actually, since 1884), but still very little is known about it and its behaviours.
• Bloody-belly comb jelly: this intriguingly-named jellyfish is lit up with moving cilia like flashing Christmas lights. It can change its colour from almost transparent to amber to deep red making it all but invisible in the gloomy depths where it lives, but its stomach remains a dark blood-red colour to mask the light from any bioluminescent prey it may have eaten. Confusingly, these voracious predators are also known as sea gooseberries, sea walnuts or Venus' girdles.
• Vampire squid: a cross between a squid and an octopus, the vampire squid can turn itself inside out. Despite its name, it does not drink blood (the name comes from its dark coloration and the skin connecting its arns which looks - a bit! - like a cape). In fact, it is the only known cephalopod to eat non-living foods, including "marine snow", which it collects with a long sticky filament set out in the dark like a fishing rod.