Fish know you're looking at them - study shows

Scientists studied the behaviour of cichlids from Lake Tanganyika, large fish known for their aggressive defence of their offspring.

During the experiment, divers dived to the nests and behaved differently:

• looking directly at the offspring
• they were close to them but looked away
• turn their bodies to the side
• look at the adult fish

The reactions were recorded using underwater cameras.

Details

Fish were significantly more likely to attack divers if they looked directly at the eggs or fry.

If a person was nearby but not looking at the nest, the level of aggression was noticeably lower.

This means that the fish are not just discerning the presence of a human, but sensing the direction of the human's attention.

Why this is important

Previously, the ability to recognise gaze has been extensively studied in primates and birds, but hardly considered in fish.

A new study shows that even these organisms may have more complex cognitive abilities than thought.

Background

The scientists also draw attention to the practical side of the discovery.

When diving or ecotourism, one must remember:

• staring at nests can cause stress
• and provoke aggression in fish,

because fish are not only able to notice humans, but also to understand where their attention is directed. And if we are talking about offspring - react to it as hard as possible.

Source

Royal Society Open Science