Marine Life Comb Jelly Photo By Marsh Youngbluth

Published on October 14th, 2009 | by Yellow Magpie


The Comb Jelly: Lethal Beauty Of The Oceans

Comb Jelly Photo By Marsh Youngbluth

One of the most colourful and delightful creatures in the sea, the Comb Jelly is an animal like no other. Unique, graceful and delicate, their bodies reflect light in a way that no master painter could ever hope to emulate.

The Comb jelly is one of the most dazzling and oldest sights in nature. Over half a billion years ago, comb jellies were one of only four types of animals that roamed the planet. While worms splintered off into what has become a diverse range of animals, sponges, jellyfish and comb jellies have almost remained the same since.

Juvenile Comb Jelly NOAA

Juvenile Comb Jelly NOAA

Animal Or Plant

Although comb jellies may look like a plant they are in fact animals that feed on small fish and crustaceans. Some are even cannibals and will feed on one another if they get the chance. Yet there not always classed as animals. There was general disagreement amongst naturalists as to whether or not they were a plant or animal. Because of this, they were classed as zoophytes (animal plants) as a compromise.

Comb jellies are the largest animals that propels themselves via cilia – a hair-like structure. They are thought to be more numerous than any animal of larger or comparable size.

Comb Jelly Swiming Mouth Agape NOAA

Comb Jelly Swiming Mouth Agape NOAA

The Comb Jelly’s Seemingly Simple Structure

Sphere or bell-jar are the two most common shapes that combs come in. They each have eight rows that contain moving cilia. A fibrous collagen gel holds mostly water in a mesoglea layer. In fact, combs are over 95 per cent water.

Although lacking a brain or even a central nervous system, they have what is called a nerve net. This is a mesh of nerve cells that forms a structure around the comb jelly’s mouth and gives it sensory information. Combs also posses a sensory organ called a statocyst which acts as a gravity-sensing device telling the comb it’s orientation in the water.

Deep Sea Comb Jelly Photo By R. Griswold

Deep Sea Comb Jelly Photo By R. Griswold

Comb Jelly’s Amazing Appearance

Comb jellies are one of the ocean’s most ethereal sights.  The beating of the cilia refracts light, making the combs look like eight shimmering rainbows. Comb jellies that live at shallow depth are transparent and colourless.

However, deep water varieties are strikingly colourful such as the bright scarlet ‘Torugas red’. Others are bioluminescent blue and green.

Are Comb Jellies Jellyfish?

Comb jellies (Ctenophores) are not jellyfish, nor are they related to the Box jellyfish, and are classified instead as Ctenophora. Unlike true jellyfish, ctenophores move by beating cilia attached to their eight comb rows. Another difference between comb jellies and jellyfish is that they do not sting. Instead they catch their prey by sticking them with mucus from retractable tentacles. Finally,true jellyfish have no anal pores whereas combs do.


Most comb jellies are hermaphrodites. It is maintained that most hermaphrodite species can self-fertilise and produce off-spring.

However, their usual reproductive method is to release tens of thousands of eggs and sperm into the water. Thus successful reproduction becomes a numbers game.

The fact that comb jellies are the  most abundant of any animals, equal or larger than them, is a testament to the effectiveness of this strategy.

Comb Jelly Photo By Kevin Raskoff NOAA

Comb Jelly Photo By Kevin Raskoff NOAA

Valuable Control or Pest?

It is believed that comb jellies preserve a delicate balance by consuming small crustaceans. Otherwise these crustaceans would eat all the phyoplankton which all higher marine species on the food chain are dependant upon.

Slightly blurring their environmental benefits are the accidental introduction of the American comb jelly, Mnemisopsis leidyi, in the Black Sea. This comb is widely blamed for the collapse of the commercial fishing industry in the region. The highly adaptable comb, christened ‘The Monster’ by the locals, is said to have been transported in the ballast tank of a US Ship.

Since its colonisation of the Black Sea. ‘The Monster’s’ population is estimated to weigh over a billion tonnes. Each individual comb can produce 8,000 offspring every 24 hours.

However, a possible solution has been drawn up to curb the problem. A cannibalistic comb jelly called Beror ovate has been introduced to hunt down and control the population of ‘The Monster.’

Comb Jelly Photo By Kevin Raskoff NOAA

Comb Jelly Photo By Kevin Raskoff NOAA

Successful Style and Substance

Even the great master of light, 20th century painting icon, Edward Hopper, would gasp in admiration at the aesthetic marvels of these resplendent creatures. Of course one cannot admire a shell. They most have strong significance too.

Comb jellies have both style and substance in abundance. They are the most successful of all large animals on the planet. A perfect marine specimen. It seems that we have still a lot to learn from these little iridescent creatures.

Vital Statistics

  • Comb jellies can measure up to 1.5 metres (five feet).
  • They can live up to and are found in every type of marine environment.

Further Reading

Check out Yellow Magpie’s Box Jellyfish: The All-Seeing Creature With 24 Eyes for insight into another remarkable animal.

The Art of Nature: Jellies is a recommended DVD containing more information on Jellyfish and Comb Jellies and is great way to learn more about these fascinating creatures.
For people living in Ireland or the United Kingdom, you can access The Art Of Nature: Jellies here.
For those who live in Canada, you can obtain The Art Of Nature: Jellies from here.

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