Dublin Sthoee lifesaving and Lifeguard, Ireland

^THEDublin Jellyfish Guide

Jelliers - they are a curse and can be a real issue during the summer in Dublin.
Here is a little information about the little devils

all the pictures are our own

Jellyfish

Do they really hurt?
it all depends! Some dont sting at all but the ones we generally encounter can be similar to a nettle sting. If you are stung let any lead swimmer or Lifeguard know and they will look after you. oh & don't panic !

Where it gets complicated is that the jelliers that we meet generally dont have much of a sting individually..... but they can shoal or swarm (hang around in large groups) and this can lead to problems. An indivual sting can get complicated when its around the face or chest. In a nutshell the jellyfish that hunt fish have stings that can affect humans. The others are suspension feeders (collect tiny particles from the water around them)and are relatively harmless. A bad sting will mark skin for some time.

We are lucky in that the really nasty ones tend to avoid where we are based.

The rule of thumb is purple good.

If you are lucky, over time, you can get a snorkel swim with non stingers or on very rare occasions with larger lion's maine. They are a sight to behold and anyone who has done one of these swims will tell you just how amazing they are.

Are they really dinosaurs ? The science bit
Even older in fact. They have been around for about 650 million years compared to humans who have been around for 1.5 milion. They are also the only remaining diploblastic creature on the planet (everything else, including you, is triploblastic meaning three layered). They have not evolved much because they have not needed to. This makes them pretty efficient at what they do.
If you really want to impress...... technically they are not fish (and they have no heart, bones or brain).

There is a great fossil on low rock beach that is widely held to be a jellyfish. Not being experts we cannot really say but it does look like one and if it is they REALLY have not changed at all in a very very long time.

How many kinds are there?
There are five commonly found on our beaches. Urban legend generates great stories of massive Portugese man o'war (technally not actually a jellyfish) but these are just that - urban legends. Just as salt water tends to exagerate the size of the fish caught it lends itself to exageration of the numbers of and type of jelliers. For the record the big five are.....

Lions Maine Jellyfish ^stinger(Cyanea) - common enough these jellyfish have very long tenticles
Moon Jellyfish (Aurelia Aurita)- the most common ones we have. These cannot penetrate your skin so effectively they are not stingers
Blue Jellyfish^stinger (Cyanea lamarckii) very pretty blue but best avoided as these are stingers.
*Compass Jellyfish*^stinger (Chrysaora hysoscella)- around Dublin these are commonly referred to as "clocks".
Barrel Jellyfish (Rhizostoma Octopus). Not very common around here, these are not stingers but have been referenced as causing an allergic reaction if over handled (who the hell handles jellyfish anyway?)

and finally........................
- Some can be eaten although we would suggest that you only eat them in restaurants (chowder is probably nicer)

- They have a natural enemy in sea turtles who feed on them

- Some do have very basic eyes

- The shiny "head" or top does not sting but stay clear anyway. The business end is the underside/tenticles. These tenticles can be next to invisible. Dont handle them after you have been stung - they just keep stinging.

- Jellyfish are the world's largest plankton

- Frank Zappa had a jellyfished named after him (Phialella zappai)

- With tenticles that can reach up to 200 feet the Lion's Maine jellyfish is the longest animal on Earth - longer than even a whale

- and finally take this with as many grains of salt as you wish. Most references on the web to jellyfish will tell you they are entirely at the mercy of wind, wave and tidal currents. Where this may be true of "by the wind sailors" or "Portugese MO'Ws", pretty much any swimmer with any interaction with jellyfish will tell you that that they will react to you being around them and will generally swim away to deeper water where they can!