Reserve two shrimps for serving and peel the rest. Cut the scallops into 1.2 cm pieces. Cut the tomatoes also into pieces and put in a bowl with the shrimps and scallops. Peel the mango, cut into cubes and place in a bowl of tomatoes. Put the red onion there, mix well.
Remove the skin from the salmon fillet, remove all bones and cut the flesh into cubes. Place the fish in a bowl with tomatoes and mango. Add chopped chili to this mixture, mix well.
Squeeze the juice of eight limes and add it to a bowl with tomatoes and fish, sprinkle with sugar, salt and pepper, stir, cover and place in the refrigerator for 3 hours.
Peel the oranges, grapefruit and remaining limes, divide into wedges and remove the foil. Drain the lime juice from the fish and tomato bowl and add the citrus wedges. Season with salt and pepper to taste, stir and serve immediately, garnish with two reserved shrimps.