male fertilizes the eggs externally by releasing his sperm onto them, and then guards them for at least three months, until they hatch. Tail fanning also occurs in order to increase the oxygen supply for the eggs. At this point, the larvae live off their noticeable stored fat until ready to hunt. Once ready, they hunt as a group rather than individually. Scientists at Hiroshima City Asa Zoological Park in Japan have recently discovered the male salamander will spawn with more than one female in his den. Only large males can occupy and guard a den. They guard the den against other males and sexually inactive females. Those that are sexually active are welcomed. On occasion, the male "den master" will also allow a second male (smaller male salamanders, named "satellite males", who do not have their own den) into the den; the reason for this is unclear. References External links BBC article with video on Giant salamanders from Japan Cryptobranchid Interest Group Tree of Life: Cryptobranchidae Chinese Giant Salamander Japanese Giant Salamander Cryptobranchoidea Extant Middle Jurassic first appearances Taxa named by Leopold Fitzinger