Advanced optics in a jellyfish eye (2024)

FAQs

What is the visual system of a jellyfish? ›

Box jellyfish (Cubomedusae) possess a unique visual system comprising 24 eyes of four morphological types. Moreover, box jellyfish display several visually guided behaviours, including obstacle avoidance and light-shaft attractance.

They possess four sensory structures called rhopalia, which carry-six eyes each. Two of these six eyes are true image-forming camera type eyes in several ways similar to vertebrate eyes. The rhopalia hang by a thin flexible stalk and in the distal end, there is a high-density crystal.

And not just one or two eyes, but 24 in total. Their eyes are bundled into four structures called rhopalia, which sit around the bottom of its bell. Two of the eye types have the capability to form images, while the other two types help with swimming navigation, avoiding obstacles, and responding to light.

The lower lens eye seems to help the jellyfish to avoid obstacles, and to move away from dark objects, but the others are a mystery. “The pit eyes are not forming images, but seem to measure the light intensity at the edges of Snell's window,” says Garm.

Jellyfish lack a central nervous system and do not have brains. They do have eyes but they are more light light sensors than our eyes that can see fine details. There are many different kinds of jellyfish and a few do have some of thier multiple eyes that are more like ours.

Using electrophysiology, the spectral sensitivity curves of the lens eyes in Tripedalia and another box jellyfish had a peak at approximately 500 nm. That means that these lens eyes sense blue-green wavelengths of light.

Jellyfish have no brain, heart, bones or eyes. They are made up of a smooth, bag-like body and tentacles armed with tiny, stinging cells.

Jellyfish don't have bones, brains, hearts, teeth or blood. However, what they do have is a network of nerves called a nerve net. This allows them to process information including light levels, temperature and chemical changes in the water around them.

The hydrozoan Turritopsis dohrnii, an animal about 4.5 millimetres wide and tall (likely making it smaller than the nail on your little finger), can actually reverse its life cycle. It has been dubbed the immortal jellyfish.

The short answer is no, jellyfish do not have brains. But this certainly does not mean they are simple creatures. In fact, not having a centralized nervous system is just one of sea jellies' many incredible tools for defense against the brutal elements of the deep blue sea.

Do jellyfish feel pain? ›

Jellyfish do not have organs or bones and only have a "basic network of neurons," according to Ocean Conservancy, an environmental non-profit. As a result, the animals don't feel pain in the same way humans do.

They are composed of three layers: an outer layer, called the epidermis; a middle layer made of a thick, elastic, jelly-like substance called mesoglea; and an inner layer, called the gastrodermis. An elementary nervous system, or nerve net, allows jellyfish to smell, detect light, and respond to other stimuli.

The visual system of fishes comprises the optical apparatus (cornea, iris and lens), the neural retina (converting an optical image into an electrical image) and the optic nerve (conveying visual information to the brain).

Some jellyfish are clear, but others are vibrant colours of pink, yellow, blue and purple. They can be bioluminescent, too, which means they produce their own light! Jellyfish have no brain, heart, bones or eyes. They are made up of a smooth, bag-like body and tentacles armed with tiny, stinging cells.

A jelly's ability to sense the world is due in large part to a specialized sensory structures, that sort of combine the eye, middle ear, cerebellum, and possibly the nose, all in one place. These little structures hang from the bell margins like earrings, and are called “rhopalia”.