Don’t trifle with jellyfish
More 4, 9pm
THINK a jellyfish is just a pointless blob drifting in the ocean? What it lacks in brains, it more than makes up for in other areas. Dr Emily Baxter, Senior Marine Conservation Officer with The Wildlife Trusts, tells us all about her favourite marine creature.
How many species of jelly fish are there in UK waters?
THERE are about six species of what we might call true jellyfish.
There’s the moon jelly; the blue jellyfish and its close relation the lion’s mane jellyfish; the big, solid, dome-shaped barrel jellyfish; the compass jelly – which has brown coloured compass-like markings on it and the mauve stinger.
We also get Portuguese man of war, by-the-wind-sailor and crystal jellies washed up. These unusual species live in open water but can often get transported here by strong winds or currents.
What do jellyfish eat?
THEY eat quite a range of things – plankton, small crustaceans, small fish, larvae and eggs. Some eat other jellies, they are quite
opportunistic in a way. Most of them float around and catch what they come into contact with.
Do jellyfish have brains?
THEY don’t have a brain but have quite a complex nerve network that controls their movements.
The edge of the bell is not completely spherical. There are indentations at various points around the edge with a tiny crystal-like thing in each one. That has sensory structures in it – ocelli which detect light and statoliths which detect gravity. This helps the jellyfish orientate and control its muscle contractions, so it knows which direction it is going in and which way up it is.
How do jellyfish sting? ALONG their tentacles they have got a lot of individual stinging cells that are triggered by touch or chemicals. It will automatically release a little balloontype thing with a little harpoon curled inside it, if it is touched, which will hook into the prey.
If a jellyfish is washed up can it still sting you?
I WOULD generally advise not to touch them. They all sting, it’s just that some have got a mild sting so we can’t feel it through the hard skin on our fingers. But if you touch one and touch your eye it might cause a burning sensation.
Why do you study jellyfish?
I WAS fascinated by how cool and beautiful they are. They play an important role in the carbon cycle.
It is estimated that between 3.7 and 6.8 billion tonnes of organic carbon can be trapped by jellyfish per year, equivalent to the United States co emissions in 2018.
HUGH DENNIS is in the presenting seat for this new series, which aims to uncover the lost history buried beneath our lawns and flower beds – and get Britain digging.
The comedian and actor is joined by a team of expert archaeologists putting their trowels and tools to work to excavate back gardens all around the country.
It’s quite good timing, given new film The Dig (inspired by a true story) has just landed on Netflix and is topping the download charts. We’re clearly interested in this stuff, or perhaps we just dream of
digging up the hydrangeas and finding some priceless historical artefacts.
This first episode sees Hugh and co head to the quiet suburban streets of Benwell in Newcastle, as they go in search of a Roman fort connected to Hadrian’s Wall and unearth some pretty exciting new evidence of life in Romanobritain.