thanks for the replies fellas.
i had 4 different rolls: all contents are wrapped in 'californian roll' (white rice). but the fish are tuna, salmon, prawns and i'm not quite sure what the other one contained but they're so tasty. i just put a little soy sauce on them and bob's your uncle! no mayo i any of them. i think they're a pretty healthy lunch option. better than sandwiches anyway.