Our Fish marketing authority tried to get a uniform set of names for everything in this state,slightly complicated by the fact that we get fish from New Zealand as well. These are called pilchards by oldtimers ,they do cook up white. Same family as mackeral & what you guys call bluefish.
I often take 12 big fresh sardines ,clean them butterfly them dredge them in flour set aside. Then in a fry pan 3oz olive oil 1 large red onion finely sliced into rings,1 carrot finely chopped 2 bay leaves 2tablespoons raisans 1 teaspoon of pinenuts 1 chilli fry gently until soft.Then add 5tablespons white wine vinegar 1 glass dry white wine 1 teaspoon sugar good squeeze fresh orange juice bring to boil then turn off immediately. Fry sardines in olive oil in seperate pan till just done ,then place in china dish pour liquid over sardines put in fridge for couple of hours eat cold. Great dish for summer, its a Sicilian thing hence raisans ,orange juice ,pine nuts. I dont normally measure things but put it down as guide. Play with it on quantities,you can add orange zest,leave chilli & so on.