noun
gammaridean amphipod; side-swimmer
A small, shrimp-like crustacean of the suborder Gammaridea, often found in marine and freshwater environments. The name literally means 'sideways shrimp'.
海岸の岩の下にたくさんのヨコエビがいた。
There were many gammaridean amphipods under the rocks on the shore.
ヨコエビは小さな甲殻類で、横向きに泳ぐ。
Gammaridean amphipods are small crustaceans that swim sideways.
Compound of 横 (yoko, 'sideways') + 海老/蝦 (ebi, 'shrimp'), referring to the sideways swimming motion of these amphipods.