From humboldt penguins to black jaguars, sperm and eggs from dozens of zoo animals are being frozen and stored at the Zoorasia Yokohama Zoological Gardens until they can be used for artificial insemination.

Placed in thin tubes, the reproductive cells taken from over 50 different species raised in three zoos — Kanazawa Zoo, Nogeyama Zoo and this one — in Yokohama are stored in tanks and frozen with minus-196 degrees Celsius liquid nitrogen.

"Theoretically speaking, the frozen sperm and eggs can be preserved semipermanently," said Noriyoshi Ichikawa, director of the Yokohama-run Preservation and Research Center at the zoo that stores the cells.