As the question states, are there any. I know things like sardines require pressure cooking or canning but what about thuings like anchovies or other, is the bone edible without having to pressure cook? My goal is to get calcium from bones with the least amount of cooking, if any at all.
Sprat and even larger fish like small jack mackerels (up to 10 cm length) are typically eaten with their spine bones when fried. The fins and heads are removed though.
Japanese cuisine knows the practice of eating Hamo eel after shortening the bones by mincing them IN the fish (special knife techniques) and poaching it....
Anchovies are sold dried in bags of small or tiny whole fish. One generally pinches off the head and stomach and eats the rest, so, yes the bones don't need to be softened by heat, but these fish are very small, even compared to what winds up as fillets in the tins.
You can eat just about ANY fish bones. I don't know if this qualifies with your "least amount of cooking". But, you can Deep-fry or Pan Fry (I use my wok with a bout a half inch of oil for this) anything from a smaller whitefish to a salmon. I cook at about 375F until it's a light brown, at which point it's crispy and easily edible. Usually only a couple minutes. I season with Salt, Pepper, Lemon or Soy and Green onion.
Here's a recipe from serious eats if that helps: - Serious Eats