Using High-Resolution Mass Spectrometry (UHPLC-HR-MS/MS) for unraveling Tetrodotoxin (TTXs) profiles and fate in marine invertebrates from the Iberian Atlantic coasts and improvement of LC-MS/MS procedures for TTXs determination

[Description of methods used for collection/generation of data] Samples were collected from the Galicia coast (Spain) and the Algarve coast (Portugal) during February March 2026. Sample preparation followed the EURLMB protocol. Analytical methods were based on Pais et al. (2025)