CER RESPONSE: Simplest animals, like sponges reproduce asexually, based on this info why are jellyfish considered more complex yet still not as complex as a mammal?

This may be a stretch but. Some species of jellyfish don’t reproduce exactly. For example the Medusa of turritopsis dohrnii is known as immortal they don’t die form old age atleast but when they reach a certain stage in their life they can turn back into their polyp state but this process requires certain cell types.

The Medusa’s reproduction goes like this:

Planula larva - Polyp - budding polyp - ephyra - Medusa(adult) - planula larva (the cycle repeats)

Hope this was right or atleast helped :)