A fish on the trail of Genghis Khan

In the world of fish Topmouth gudgeon Pseudorasbora parva, a small cyprinid native to East China, has matched and gone beyond the great Mongol invasion, resulting in the vast range expansion covering much of Asia, Europe and now with a foothold in North Africa. The stealth invasion started in the 1950’s with the end of the Chinese civil war (from around 1840 to 1949) which had restricted human population mobility and trade. At that time, there was an increasing need for developing new sources of animal protein and black carp, grass carp, silver carp and big head carp were rapidly introduced from East China especially from the middle and lower reaches of the Yangtze River basin to many other places including Yunnan, Qinghai, Gansu and Xinjiang. This species had been cultured traditionally in East China for a long time with specific culturing techniques. These carp introductions for aquaculture have been the beachhead of topmouth gudgeon’s great escape.

Small in size (maximum length circa 9cm), highly fecund with batch spawning and nest guarding behaviour and highly tolerant to environmental changes, topmouth gudgeon has all the attributes of a successful invader. Its first introduction outside of China was in reservoirs and ponds around the black sea as part of a fish farming agreement between China and the former Eastern block. Following long distances and hitchhiking cross country with movements of carp, it rapidly escaped and colonised local waters, dominating communities in ponds and lakes. Recently identified as a healthy carrier of a deadly non-species specific eukaryotic parasite Sphaerothecum destruens, it now poses a threat to European fish diversity.

Preserved material will be compared to material collected from populations established from the first introduction in each country within the non-native range. Topmouth gudgeon has been introduced for several decades to countries with clear contrasting climatic conditions such as Poland, Italy and Algeria. This will provide a unique opportunity to study adaptation under contrasting climatic conditions. Populations will be compared for their life history traits and parasitic communities as well as their population genetic structure within native range but also across introduced range. In addition, live topmouth gudgeon will be brought back from China and various parts of the non-native range to characterise the reaction norms of different populations along thermal gradients. Individual fitness, measured as the number of reproductive events, size of batches and larval growth will be measured for several contrasting populations under a range of controlled thermal challenges. This will allow the evolutionary and phenotypic shift that has occurred during topmouth gudgeon invasion to be measured.

Beyond the immediate scientific interest this expedition represents a cultural and historical journey where an innocent movement of fish from the East coast to the West part of China has rippled all the way to England 50 years later.

The TEAM

ALL ALONG THE EXPEDITION I WILL KEEP THE BLOG ALIVE SO GET IN TOUCH, ASK QUESTIONS AND I WILL BE AS REACTIVE AS POSSIBLE TAKING YOU ALONG THE JOURNEY. :-)

Thursday 8 July 2010

Day 24

This morning after checking the local market we rapidly headed North towards Harbin and the Amur River basin. Torrential rain all day and massive pot holes in the road made our progression fairly slow. This part of the country looks very industrial with an old look of a 70’s communist town as you imagine it from our Western perspective. People here are much taller than in other parts of the country (Russian influence!), are louder when they talk, their dishes are massive and they are not so excited to see foreigners although you still have the occasional Helloooo!
After locating the river and speaking to the locals we rapidly understood that no living creatures could be found in these local black rivers as they are so heavily polluted. So trying to waste no time we went further North trying to find better waters. On the road we found local fishermen in a village called “the seven families” who had already sold out their topmouth gudgeon for the day (highly prized here, I am not sure why) but that they will get some for us tomorrow morning (let’s wait and see). We need a sample from here as the local temperatures in the winter regularly plunge to -40 oC and goes up to +30oC in the summer. It would be interesting to see how the fish have adapted to these extreme temperatures.
Something, I haven’t mentioned so far in the blog (although it fills up quite a lot of our discussion, like old soldiers comparing their wounds) is the state of public toilets in China! You have some really wicked ones with a ditch over which you squat and separated by small walls. When you enter, you have to hyperventilate as the foul smell attacks the back of your throat and from time to time you have the pleasure of seeing a head poking over the wall and saying hellooo!
Tonight, we are all exhausted, a mixture of the driving, the drop in temperature (fit is the first time we have worn our jumpers) and disappointment with our fish collection. We can see that time is running out and we are all anxious to make sure we complete our collection and make this expedition and overall success.
Finally, we had all a deep thought for our friend and colleague Bernd after the football last night (we know the feeling) and say to Rafa and all online Spaniards "Hola" and good luck for the final!
It is midnight here and tomorrow we wake up at 5.30 so straight to bed now and no bedtime story ;-)
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2 comments:

  1. Bernd9 July 2010 at 01:20

    Keep it up guys! I'm sure you will manage to find some fish soon. It must be frustrating not to catch anything after all that travel. With all this frustration it's easy to forget what an adventure you are on. I realise this now only after I'm back. At the time it feels often too sureal. So make most of your time and stay positive. As to the football, well I blame the bloody octopus! No seriously Spain deserves to be in the final they are techically by far the best team. I think Germany played the most exciting football of the tournament, but of course we all know that this has never won a competition!

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  2. Rafa Miranda9 July 2010 at 09:50

    Bern, I am sorry for the german defeat(not really ;-D)
    I think that Germany-Spain match was a good match, and really it could be the winner both.
    Anyway, I hope that your fishing expedition will be successful, and your misfortunes will be only distant bad dreams.
    Animo!!! (in spanish luck!!)

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