Zebrafish their larval stages. In 2011, the British Heart Foundation ran an advertising campaign publicising its intention to study the applicability of this ability to humans, stating that it aimed to raise £50 million in research funding. Zebrafish have also been found to regenerate photoreceptor cells and retinal neurons following injury, which has been shown to be mediated by the dedifferentiation and proliferation of Müller glia. Researchers frequently amputate the dorsal and ventral tail fins and analyze their regrowth to test for mutations. It has been found that histone demethylation occurs at the site of the amputation, switching the zebrafish's cells
Medjed (fish) figurine from Oxyrhynchus of one of the sacred Medjed fish has many attributes typical of mormyrids: a long anal fin, a small caudal fin, widely spaced pelvic and pectoral fins, and the downturned snout. Medjed (fish) Medjed was a species of elephantfish worshipped at Oxyrhynchus in ancient Egyptian religion. These fish were believed to have eaten the penis of the god Osiris after his brother Set had dismembered and scattered the god's body. A settlement in Upper Egypt, Per-Medjed, was named after the fish and is now better known under its Greek name "Oxyrhynchus". The elephantfish (family Mormyridae) are medium-sized