In a non-reactive casserole dish, preferably glass, or in a gallon-sized Ziploc bag, combine the tuna, onion, tomatoes, garlic, salt, pepper, Tabasco, oregano and basil. Cover with lemon and lime juice. Let sit covered in the refrigerator for an hour, and then stir to ensure all the fish comes into contact with the marinade. Let rest for about six hours. Fish should appear white and cooked.