BACKBLIP: Loving the alien - when its at home

BACKBLIP: I was unable to blip while I was away in China for over two weeks (blipfoto is not accessible there). I'm attempting to catch up!

Today, 12th November 2012, was an immensely important day for us, being the day we completed most of the Chinese paperwork for our adoption. But paperwork makes for a pretty dull blipfoto so the alternative is something of a busman's holiday for me. I found this tank of live crabs in the supermarket near our hotel in Nanchang, all for sale along with tanks of fish (a huge variety) and even a tank of live turtles! The reason I was so excited to find these crabs is that they are Chinese mitten crabs (given the Scientific name Eriocheir sinensis), so-called due to the 'hairy' growths on their pincers (it isn't actually hair as such). This is an invasive non-native species in the UK. It migrates from the sea up into rivers as part of its life cycle where it can cause significant undermining of banks due to extensive burrowing. They are large and very aggressive crabs and are likely to be damaging local ecology in both coastal/estuarine and river environments in the UK where they have no natural predators. They are also likely to be largely free of the natural parasites and diseases which may help to control their numbers in their home range. We don't yet have them in Scotland but, as they are now recorded in the Newcastle Tyne on the east coast and Morecambe Bay on the west, it is surely only a matter of time before Scotland sees its first Chinese mitten crab in the wild.
So why is this a busman's holiday? Well, my colleague and I lead on invasive non-native species policy for our agency and will be closely involved if and when this animal makes its first appearance in Scottish waters. As such, it was good to be able to take a close look at some in China, where they actually belong!