Comb jellies — also known as ctenophores — look almost like creatures from another planet. Many have transparent bodies that glow in the dark, and the eight rows of flickering comb plates — the animal’s swimming gear — reflect the sunlight in all the colours of the rainbow.The truth is that these are some of the oldest living animals on the planet — even though in many ways we still know very little about them. Comb jellies are often very fragile and are thus difficult to collect. As a consequence, many species have not been properly described and lack scientific names. This is in spite of the fact that there are only around 150 species

of comb jellies in the world, approximately ten of which have been observed in Norway. Several comb jellies are voracious predators and can have an impact on zooplankton populations — especially since they can sometimes be quite numerous. Comb jellies are hermaphrodites, which means that an individual is both sexes at the same time, and they multiply very quickly when conditions are good. Fortunately, comb jellies don’t sting. Unlike stinging jellyfish, such as lion’s mane jellyfish, comb jellies lack venomous stinging cells. Instead, they have sticky cells called colloblasts, which adhere to their prey.

If you find a comb jelly, you can carefully pick it up in a glass without getting stung. Hold it up to the sun and see the beautiful play of colours in the flickering comb plates that have given the animal its name — a name which doesn’t quite capture how fascinating these creatures are.