In this study we analyse how offspring fitness constrains spawning phenology in a large migratory apex predator, the Atlantic bluefin tuna. The reproductive schedule of Atlantic bluefin tuna varies between spawning sites, suggesting plasticity to local environmental conditions.

The early spawning is constrained by thermal inhibition of egg hatching and larval growth rates, but some other factors must prevent later spawning. Matching offspring with ocean productivity and the prey peak might be an important driver for bluefin tuna spawning phenology. This finding is important for predictions of reproductive timing in future climate warming scenarios for bluefin tuna.

Reglero P, Ortega A, Balbín R, Abascal FJ, Medina A, Blanco E, De la Gándara F, Alvarez-Berastegui D, Hidalgo M, Rasmuson L, Alemany F. Atlantic bluefin tuna spawn at suboptimal temperatures for their offspring. Proceedings of the Royal Society B: Biological Sciences. 2018 Jan 10;285(1870):20171405.