Translation guide
The term 'nekton' refers to aquatic animals that can swim actively against currents. In Japanese, it is typically expressed using the loanword ネクトン or the native term 遊泳生物.
Referring to the ecological category of marine or freshwater organisms that can move independently of water currents, such as fish, squid, and marine mammals.
A native Japanese term meaning 'swimming organisms'. Used in biology and ecology, but less common than ネクトン.
Nekton can move against water currents.
Literally 'swimming animals'. Sometimes used to emphasize the animal nature of nekton, but 遊泳生物 is more inclusive.
A typical example of nekton is fish.