Though two fish species are marketed as escolar, L. flavobrunneum is considered the true escolar internationally, and the lesser-valued Ruvettus pretiosus is more widely known as oilfish or castor oil fish. Though considered a succulent species by those familiar with it, escolar’s association with oilfish has tainted its reputation. The Food and Drug Administration says escolar has “purgative” qualities and advises against importation. But many chefs who handle escolar contend that it’s R. pretiosus that’s to blame for making people sick. Found in tropical and temperate waters worldwide, escolar is almost exclusively a bycatch of tuna longline fisheries. Escolar is imported from Fiji, Ecuador and other countries with warmwater tuna fisheries. In the United States, it comes primarily from the Gulf of Mexico. Since tuna fishing is best during the late phases of the moon, there’s usually more escolar on the market in the days following a full moon.