The boneless and heartless jellyfish have become a popular draw for the Vancouver Aquarium. The facility just completed its 'Jelly Invasion' promotion, which saw 17 species from all around the globe.

"In previous years we've kind of gone through various states of jellies and no jellies. Definitely if they've ever gone away we have lots of people commenting because it's definitely one of the most popular exhibits", said marine biologist Mackenzie Neale.

Every ocean has jellyfish. Coastal zones are the ones that commonly have large and colorful jellyfish. As a matter of fact, jellyfish are known as the oldest multi-organ animal. Neale said that he found the jellyfish really interesting because of their natural quality of being so delicate. Moreover, they have been able to survive in the wild for thousands of thousands of years. There are various types of jellyfish in oceans ranging from lethal to innocuous ones.

Australia's box jelly is known as the most dangerous one because of its toxin more potent than the cobra venom. It is capable of killing a person in just a matter of minutes.

It is very challenging to keep jellies in specialized tanks because they are so delicate that even just rubbing against acrylic, which is extremely smooth, can cause damage of them.