Genetic verification of the louvar (Luvarus imperialis) in the diet of orca (Orcinus orca)

We report the first genetically confirmed record of louvar ( Luvarus imperialis ) as prey of orcas ( Orcinus orca ) in the southern Gulf of California, Mexico. Although the prey could not be visually identified during the brief encounter, a tissue sample opportunistically collected from the water column following the feeding event enabled definitive species-level identification through DNA sequencing of the 12S rRNA gene. Previously, teleost prey reported for orcas in the Mexican Pacific were limited to three sunfish species ( Mola mola, Mola alexandrini, and Masturus lanceolatus ) and yellowfin tuna ( Thunnus albacares ). This finding expands the documented prey spectrum of orcas and provides further evidence of their opportunistic foraging on large pelagic teleosts. To place this interaction in a regional context, we compiled available records of louvar sightings (n = 13) from coastal waters surrounding the Baja California Peninsula. These records provide baseline information on the occurrence of this cryptic and rarely reported species in Mexican waters. Together, the findings demonstrate the value of combining opportunistic field observations with molecular tools to identify otherwise unrecognizable prey and improve our understanding of pelagic food-web interactions.