Isotopic data supporting the Silver warehou (Seriolella punctata) research survey 2018

We obtained 25 Seriolella punctata specimens during a fisheries-independent research survey in 2018 aboard the AGS-61 “Cabo de Hornos” (Instituto de Fomento Pesquero, IFOP). Specimens were collected from the open waters of Chilean Patagonia (Fig. 1a). Following capture, individuals were immediately frozen at -20°C for transport and subsequent laboratory processing. In the laboratory, each specimen's left eye was thawed and moistened with deionized water following established protocols. We measured the diameter of each intact eye lens using an Olympus SZX16 dissecting microscope (20X magnification) equipped with a ZEISS Axiocam 208 digital camera. To ensure standardized sampling, we micro-dissected three laminae from each lens using fine-tipped tweezers. The lens was considered to constitute the “core” once reduced to a diameter of < 500 μm. This core, which is typically denser than the surrounding laminae, resists further delamination. Concurrently, we obtained potential prey items from stomach contents. Items with the lowest detectable degree of digestion were selected and processed to ensure tissue integrity. Both lens laminae (n = 75) and prey tissues (n = 114) were placed in separate tin capsules and dried for 12 hours prior to Stable Isotope Analysis (SIA). We analyzed all tissues for δ15N and δ13C at the Universidad Andres Bello Stable Isotope Facility (LAI). Analysis was performed using a continuous flow (CF) Nu-Instruments mass spectrometer coupled with a Eurovector EA-3024 elemental analyzer. Isotope ratios are reported in δ notation relative to Vienna Pee Dee Belemnite (VPDB) for carbon and Atmospheric Nitrogen (AIR) for nitrogen.