Linked from
The 12 pages that link to European eel, each with the reason it gives.
Animal migrationBroader topic: Its long oceanic journey links distant feeding and spawning regions.
EelBroader topic: Its transoceanic life cycle is one of the best-studied eel migrations.
CatadromyBroader topic: Its long migration is the best-known example of the catadromous life cycle.
EuryhalinityBroader topic: Its life cycle spans habitats with sharply different salinities.