Thanks everyone for your lovelyy comments.
Chopstix, do you alsoo call them 'tuk tuk'?
Anau, I have no idea what they are called and if at all they have a special name, but now I am curious and will find out.
Yakuta, Actually what happened was, they ordered fish and chips, then they did get a whole fish each and chips! We were amused and I wondered what they would make of it especially going by their sizes. We usually eat whole trout here anyway. they just started tucking into their meal and said it was the best fish ever. Now back in Geneva, I will have to go looking for whole Tilapia. I am looking forward to preparing it actually.