Shrimp and Tilapia Tacos with Mango Salsa

For the mango salsa:

• 2 mangoes, peeled and chopped
• 1/2 red onion, finely chopped
• 1 fresh jalapeño, seeds removed, finely chopped
• 1 tablespoon fresh cilantro, chopped
• Salt, to taste

For the tacos:

• Vegetable oil in spray, as needed
• 1/3 cup melted butter
• 1/2 teaspoon salt
• 2 garlic cloves, finely chopped
• 1 tablespoon fresh cilantro, finely chopped
• 1 tablespoon lemon juice
• 1 lb uncooked shrimp, peeled and deveined
• 4 breaded tilapia fillets, cut into long strips
• 12 corn tortillas
• Lemon slices, as needed