This arduous migration is not just about reaching their spawning grounds; it's also a journey of love. Eels have been observed to form pairs during their migration, with the male and female swimming together, supporting each other through the grueling journey. This remarkable display of devotion and cooperation increases their chances of successful spawning and ensures the continuation of their lineage.

Some eel species undertake incredible migrations, which play a crucial role in their romantic storylines. The catadromous eels, such as the American eel (Anguilla rostrata), migrate from freshwater or brackish environments to the ocean to spawn. During this journey, they often travel thousands of kilometers, facing numerous challenges and predators along the way.

: Many species of eels spawn in deep-sea environments, making direct observation of their mating behaviors challenging.

Eel mating rituals are a sight to behold. During the mating season, male eels will often engage in a series of undulating movements, vibrating their bodies to create a "love dance." This display of affection is meant to attract a female partner and demonstrate the male's suitability as a mate.

: Tools for deep behavioral phenotyping help scientists understand complex interactions and "relationships" between animal subjects.