Eeelastic

Eels travel in old age

New Zealand long-finned freshwater eels
swim in clear rivers,
like the turquoise Clutha River,
like slick olives in the water.

After forty years,
they swim in the ocean near Tonga,
Becoming male and female
in the ocean’s olive brine.

Into the water,
they throw the act of mating,
And the leaf-like larvae are taking
the backward trip in time.

https://en.wikipedia.org/wiki/New_Zealand_longfin_eel