How do fish that live in dark caves get by without eyes?

What Crafty Clover says in this video

Intro

Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. How do fish that live in dark caves get by without eyes?

The Big Idea

Some fish live in caves where no light ever shines. Many of them have no eyes at all! So how do they get around?

Losing Eyes

Step one: Losing Eyes. Over many generations, cave populations of some fish, such as the Mexican tetra, lost their eyes and most of their color. In total darkness, seeing and color are no use.

Feeling Water

Step two: Feeling Water. They sense tiny water movements with special cells along their bodies. That helps them feel what is nearby.

Smell and Touch

Step three: Smell and Touch. They find food by smell and touch. Their bodies use less energy than fish that live in light.

A Closer Look

Let's take a closer look! They have no eyes. Their skin is pale. They sense water movements. They smell their food.

Quick Facts

Quick facts! Cave fish usually grow and eat slowly, because food is scarce in a dark cave. Some Mexican tetras live in caves, and their cousins live in rivers with eyes. Eyes use a lot of energy, so losing them saves energy. Some cave shrimp and salamanders are pale too.

Think Like a Scientist

Now, think like a scientist! Draw a fish that lives in a dark cave. Leave out the eyes. Which senses would you give it instead? Show where they would be on its body. Explain your fish to a grown-up.

Outro

Some cave fish, like cave populations of the Mexican tetra, lost their eyes and color over many generations. They sense water movements with special cells and find food by smell and touch. Science is amazing! Keep asking questions! The more you look around, the more wonders you will find, so keep your eyes open! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!