Anemones are immortal.

[ClownWrangler]

I had a black widow BTA split the other day and thought to myself, those are not two new anemones, they are the same one I had before it split. If you clone an anemone asexually 100 times over 100 years, then the offspring are 100 years old from the standpoint of genetics. Do they age? I there a limit to how far this can go? Apparently not from some of the research I have done. Anemones don't age. What other animals in our tanks can live forever? Corals as well?

 

[P-Dub]

I had a black widow BTA split the other day and thought to myself, those are not two new anemones, they are the same one I had before it split. If you clone an anemone asexually 100 times over 100 years, then the offspring are 100 years old from the standpoint of genetics. Do they age? I there a limit to how far this can go? Apparently not from some of the research I have done. Anemones don't age. What other animals in our tanks can live forever? Corals as well?

Yes. Technically, corals as well.

 

[N.Sreefer]

Plants also some plants reproduce asexually the largest most dense organism on earth is a stand of trees

"Pando is believed to be the largest, most dense organism ever found at nearly 13 million pounds. The clone spreads over 106 acres, consisting of over 40,000 individual trees. The exact age of the clone and its root system is difficult to calculate, but it is estimated to have started at the end of the last ice age"

 

[MaxTremors]

There are some anemones that can survive (at least genetically) indefinitely. But individual animals definitely have a lifespan and age, though they’re capable of repairing their DNA and in some cases stopping it from degrading altogether (they have telomeres that basically stop their dna from fraying), this also mostly stops them from getting tumors or cancers like most other animals do when they age. But they do age, it’s just very, very slowly, individuals can live thousands of years if they’re lucky. But not all species can live indefinitely, there are many species that do not reproduce through binary fission and only reproduce sexually. Definitely fascinating to think about.