Wednesday Wildlife - The Amazonian Jellyfish

Normally my Wednesday Wildlife postings are an excuse to show off my wildlife pictures but I have never even seen the subject of this week’s post. I didn’t even know we had a Freshwater Jellyfish until I read about it in the wonderful new book ‘Bugs Britannica’.

Picture source – Internet (various sites – unattributed)

We tend to think of jellyfish as marine species but there is a little known freshwater species – the Amazonian or Freshwater Jellyfish (Craspedacusta sowerbyi). It is the size of a 5p piece. They have a whorl of up to 400 tentacles tightly packed around the bell margin. It was first found in the water lily tank at Kew and was assumed to have hitch-hiked on the roots of plants brought back from a South American expedition. They were later found in the ship canal at Exeter where they lay low for a while before being rediscovered in the 1970s.

The best known examples of this species appeared in a flooded sandpit at Doncaster’s Hatfield Water Park during the warm summer of 2002. They first appeared in ones and twos and multiplied in the warm sunshine so that by August there were thousands pulsating in the shallows. In places there were as many as 45 per square metre.

In parts of the mid-west and the great lakes area of North America, seeing one is considered to be a sign of good luck. I would certainly think myself lucky if I were to see one!