Today, I ate a grilled mackerel for lunch. It is ok for me not to eat meat but it is really hard to refrain from eating fish. Especially grilled mackerel is my most favorite dish.
This morning I watched TV and learned that fish may care for other fish. It is an interesting experimental trial. In a big tank, there are two small rooms; one is marked red and the other is blue. A male fish can get food whichever room he enters. However, when the male fish enters the red room, a female fish, who is swimming within his sight, can also get food. Then the male fish chooses to enter red room, not blue room.
On the other side, when there is other male fish within his sight (not female), he enters blue room.
What makes the story even more interesting is that the female fish who is within his sight is unfamiliar to him and his familiar female fish is swimming near him, then he enters blue room. He cares about his familiar female fish.
He might worry about the female’s jealousy!?