What is the shortest-lived vertebrate?

The shortest-lived vertebrate is the pygmy goby, specifically Eviota sigillata.

This tiny marine fish lives on tropical reefs across the Indo-West Pacific, from the Seychelles to Micronesia. Its entire life cycle can last no more than about 59 days, making it the vertebrate with the shortest recorded lifespan. The fish grows to only around 3 centimeters.

Its brief existence is divided into distinct stages. The larvae spend roughly three weeks drifting in the open water, then about two weeks settling onto a reef, followed by approximately three weeks as adults. Reproduction must happen quickly because the adult phase is extremely short.

The name can cause confusion because “pygmy goby” is a loose common-name shorthand. The species is also called the seven-figure pygmy goby or adorned dwarfgoby. Mayflies are often offered as an answer, but they are insects, not vertebrates; the turquoise killifish is short-lived too, but typically survives much longer.