Epigenome in highly regenerative animals?

Highly regenerative species like the zebrafish have a rich supply of stem cells that enables them to do what we can't (like regenerate organs and limbs). Hence, I would assume that epigenetic changes in these organisms is highly important for the maintenance of those stem cells - In fact, this is true for all species (article below). As to whether there is more or less epigenetic changes in a zebrafish relatively to a human (whose genome is far more complex), I'm not sure. It certainly is an interesting question that I'd be interested in knowing myself!

Emerging evidence indicates that epigenetic regulators are critically required for the maintenance of tissue-specific stem cells and that the epigenetic marks are altered in stem cells during physiological aging.