noun
baby spotted turtle; young Japanese pond turtle
Refers to a young Japanese pond turtle (Mauremys japonica), often seen in pet shops or in the wild. The name literally means 'coin turtle', from the small, coin-like appearance of the hatchling.
See also: 石亀
ペットショップで小さなゼニガメを見つけた。
I found a tiny baby turtle at the pet shop.
ゼニガメは成長すると甲羅の模様
As the baby turtle grows, the pattern on its shell changes.
石亀 (イシガメ) is the general term for the Japanese pond turtle (Mauremys japonica), while ゼニガメ specifically refers to the young or baby stage of this species.
Compound of 銭 (zeni, 'coin') and 亀 (kame, 'turtle'), referring to the small, round, coin-like appearance of the hatchling. The exact origin is uncertain, but it is a descriptive name based on the turtle's size and shape.