Jellyfish Day - November 3
Fri, Nov 3, 2023

Jellyfish Day

Jellyfish Day is a holiday dedicated to the mysterious and unusual invertebrate marine life. Celebrated on November 3rd every year, this day is a perfect opportunity to learn more about this fascinating marine animal.


Jellyfish have been present on the planet even longer than dinosaurs and, unlike them, have survived any cataclysm that has come their way. Scientists have proven that jellyfish appeared 500 million years ago, as confirmed by fossils found in Utah in 2007. The age of the find was 505 million years.

Jellyfish have always been seen as something special and unusual, due to their translucent bodies, tentacles of different lengths, and the absolute absence of any organs. Scientists were unable to classify these creatures, as only plants, animals, and people were known.

Interesting facts

  • For a long time, jellyfish could not be studied in detail.then the microscope was developed, and specialists began to study them again.
  • In 1866, zoologist Ernst Haeckel published his book General Morphology of Organisms, which detailed the evolution of animals, including jellyfish.
  • According to Haeckel, jellyfish separated into a separate class at an early stage in the development of life on the planet, which is why they are so different from other species.
  • Jellyfish need a minimal amount of oxygen to breathe, they reproduce quickly, and they shrink in size when they lack food.
  • 95% of the body of a jellyfish is water, and the remaining 5% is a special substance of mesoglea, which consists of nerves, muscles, and protein.
  • Jellyfish are beautiful, as they come in different colors, they glow, but they can be poisonous.

How to take part

There is a wealth of information in our information space about jellyfish – films, books, articles, to read and watch – so use this day to learn more about these creatures. A great way to celebrate the holiday is to visit an aquarium with family or friends.

When is Jellyfish Day celebrated in 2023?

Jellyfish Day is observed on November 3 each year.


Weekday Month Day Year
Friday November 3 2023
Sunday November 3 2024
Monday November 3 2025
Tuesday November 3 2026