Abstract
The Atlantic goliath grouper (Epinephelus itajara) experienced a severe population decline in the latter half of the 20th century, leading to a U.S. harvest moratorium in 1990. Despite uncertainty surrounding the recovery of species, some fishers claim that goliath grouper are negatively impacting commercial and recreational fisheries, with many advocating for reopening the fishery. To assess these claims, this study used environmental DNA (eDNA) metabarcoding to investigate the feeding ecology of juvenile goliath grouper in Southwest Florida. Fecal samples from thirty-one juvenile goliath grouper were sequenced, identifying eighteen prey taxa across three classes, eight orders, and fifteen families. Five of these eighteen prey taxa were not previously known to be juvenile goliath grouper prey; these included the sandy sea cucumber (Holothuria inornata), leopard searobin (Prionotus scitulus), remora (Echeneis naucrates), inshore lizardfish (Synodus foetens), and jenny mojarra (Eucinostomus gula). Additionally, three prey taxa identified herein were considered commercially valuable; the Atlantic blue crab (Callinectes sapidus), southern pink shrimp (Farfantepenaeus notialis), and gulf stone crab (Menippe adina), with the gulf stone crab being the most frequently consumed prey taxa in the study. These findings show that fecal metabarcoding can be an effective alternative to traditional methods and highlight the need for further research on the management implications of a predator prey relationship between goliath grouper and stone crabs.
