Java: how to properly implement an interface?

Question

Java

Hello.
There is an interface CalculateSum which has a single method recieveSum. Also, there is a parent class Animal from which the classes Fish and Bird are inherited. And accordingly enum FISH(5), BIRD(8).
Each of the inherited classes (Fish, Bird) is implemented from the CalculateSum interface.

class Fish extends Animal implements CalculateSum {}
class Bird extends Animal implements CalculateSum {}
public enum Types {
    BIRD(7), FISH(3);

    int type_of_animal = 0;
    Types(int type) {
        this.type_of_animal = type;
    }

    public int getType_of_animal() {
        return type_of_animal;
    }
}

In addition, there is a separate class with methods addAnimal, getAnimal and has an ArrayList in which animals are written according to user-specified data.
For example: the class Fish, which has Types.FISH set, is added to the ArrayList.
Problem with getAnimal method

for (Animal animal : animals_list) {
      if(*здесь своё условие*) {
                *и здесь необходимо вывести на экран recieveSum из класса Bird, либо Fish в зависимости от типа животного*
      }
}

At the same time, the Animal class should not be implemented from CalculateSum, but only the Bird and Fish classes. How to implement it correctly?

Answer 1

for (Animal animal : animals_list) {
      switch(animal.type_of_animal){
          case "3":
              FISH.reciveSum();
              continue;
          case "7":
              BIRD.reciveSum();
              continue;
    }
}

Approximately the structure is