sea monkey; brine shrimp
Trademarked name for brine shrimp sold as novelty pets; often used generically in Japanese to refer to the creatures themselves.
See also: ブラインシュリンプ
When I was a child, I got a kit to raise sea monkeys.
シーモンキーは実はブラインシュリンプの一種だ。
Sea monkeys are actually a type of brine shrimp.
From English 'Sea-Monkeys', a trademarked brand name for brine shrimp sold as novelty aquarium pets.