In 2009, a major scare in the Auckland Region of New Zealand was sparked after several dogs died of tetrodotoxin poisoning after eating Pleurobranchaea maculata (grey side-gilled seaslug) on beaches.
Quinidine also blocks the slowly inactivating, tetrodotoxin-sensitive Na current, the slow inward calcium current (ICa), the rapid (IKr) and slow (IKs) components of the delayed potassium rectifier current, the inward potassium rectifier current (IKI), the ATP-sensitive potassium channel (IKATP) and Ito.
Members of this family also synthesize tetrodotoxin (TTX), an ancient marine alkaloid and powerful neurotoxin (Na+ pump inhibitor, 1 mg can kill an adult) that serves to protect members of an order of fishes, the Tetraodontiformes (tetras-four and odontos-tooth), which include the puffer fish (see fugu, raw puffer fish served in Japan).