Fish numbers are numbers defined by the Japanese googologist Fish. There are seven Fish numbers: * Fish number 1 is an extension of the Ackermann function and is comparable to \(f_{\omega^2+1}(63)\); * Fish number 2 is an extension of Fish number 1 and comparable to \(f_{\omega^3}(63)\); * Fish number 3 uses s(n) map and comparable to \(f_{\omega^{\omega+1} imes 63+1}(63)\); * Fish number 4 combines Fish number 3 with an oracle system; * Fish number 5 uses a system that reaches \(\varepsilon_0\); * Fish number 6 uses an extension of that system which reaches \(\zeta_0\); * Fish number 7 combines Fish number 6 with an oracle system in Rayo's function.