Life History of the Gray Snapper at the Warm Edge of Its Distribution Range in the Caribbean

Knowledge of the life history of populations at the warm edge of their distributional range can provide a better understanding of how they will adapt to climate warming, including potential poleward redistribution. The range of Gray Snapper Lutjanus griseus has the potential to expand along its northern temperate fringe, but little is known about this species in the warmest portion of its range. We studied the age, growth, reproduction, and mortality of commercially caught Gray Snapper in the Guatemalan Caribbean, where sea surface temperature consistently exceeds 26 degrees C. Longevity was estimated as 10 years, and von Bertalanffy growth parameters that were consolidated through Bayesian estimation incorporating earlier estimates from the Caribbean region were as follows: asymptotic length (L-infinity) was 35 cm, the growth coefficient (K) was 0.56 year(-1), and the theoretical age at zero length (t(0)) was -0.7 year. Gray Snapper grew slowest in April, prior to the rainy season, and at the onset of the reproductive season, which lasted to September. Fifty percent of the Gray Snapper matured at 31 cm and at 3.5 years of age. Gray Snapper had a lower maximum size, longevity, and peak reproductive investment, a protracted spawning season and reproductive life span, and elevated natural mortality at the warm edge of their distribution relative to temperate climates. Despite the plasticity in life history of Gray Snapper observed in this study, their potential to further adapt to warming remains unknown.