Date of Award

Summer 2021

Document Type

Open Access Thesis


Marine Science

First Advisor

Virginia Shervette


Yellowtail snapper Ocyurus chrysurus is an important fisheries species in the US Caribbean; in waters of Puerto Rico, it ranks second for reef fishes in terms of annual total commercial landings. However, a paucity of information exists concerning basic life history information for Caribbean yellowtail snapper populations. This study provides the first comprehensive documentation of age, growth, and reproductive biology of yellowtail snapper from the Caribbean and is the first to directly validate age estimation in this species. Sampling of 1731 yellowtail snapper occurred in Puerto Rico and the U.S. Virgin Islands during 2013-2021 from fisheries-dependent and –independent efforts. Fish ranged in size from 68-690 mm (total length) and in age from 0-26 years. Regression equations were calculated to determine length-length and length-weight relationships using total length (TL), fork length (FL), standard length (SL), and weight. Total length and age data fit to a von Bertalanffy growth curved for all samples combined from across the U.S. Caribbean, but not including the cast net age-0 samples, yielded the following relationship: TLt = 537[1 – e-0.11(t + 3.32)]. Yellowtail snapper in the U.S. Caribbean demonstrated a male to female sex ratio of 1:1.14 and exhibited year-round spawning with a peak spawning period in April. Age validation was conducted comparing bomb radiocarbon Δ14C measured in snapper eye lenses formed during the first year of life. Information from this study can be used by fisheries resource managers when evaluating the health of the yellowtail snapper fishery in the region.