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. :-)

Tuesday, 6 July 2010

Day 22

What a day! The most astonishing moment so far. We set off this morning from Xingcheng and as usual checked the local market but it was essentially marine species. One of the rare towns that still retains its original city wall from the Ming dynasty. Then we drove deeper into Manchoury territory (Liáoning Province) and we went off road through little villages trying to find the river. After a lot of hesitation about whether the car would make it or not, we finally located a stunning part of the river surrounded by mountains. Not a soul just us, the sunshine and the feeling of being alive. It was magical. Yahui taught me how to use the throw net (harder than it seems) and I kept catching our fish despite poor throws while he couldn’t catch any although his throws were very pro… beginner’s luck! This part of the country is called the Gulin of the North with a well known ice valley (the road we took). We were on a little cloud all day and greatly missed Bernd who would have loved it. This part of China is not as touristy as other part of the China and it is dictated by the wild and imposing landscape. There is a constant breeze coming from the Pacific which makes the high temperature very pleasant. Definitely a place to come back.

Tonight we ended up in Zhuanghe a few km down from Dandong, the border town with N. Korea where we are planning to go tomorrow morning. Yahui has some contacts there so we should be able to get a sample from N & S Korea which would be interesting as all their rivers have a very different history to the Chinese ones we sampled.

For dinner we went to a Korean restaurant which consisted of a barbecue incorporated in the table and everyone cooked their own food. Lovely. To digest our feast we went to the square to play a local game which consists of juggling some metal coins attached to a crown of featherswith your feet . You see people playing it all around China in parks and streets with all generations and sexes. I will bring a couple back to the UK (they cost 2p each) and start this Chinese game as a fashion in Bournemouth. I always told my wife that I was a fashion guru but she had some doubts…;-)

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3 comments:

  1. Anonymous8 July 2010 at 06:37

    How do you keep the fish? Or do you just get a bit of flesh and fix it to bring back to the UK? I am curious.
    Sunday's World Cup final...!Viva España!
    Genoveva

    ReplyDelete
  2. Anonymous8 July 2010 at 20:42

    Rudy, you are displaying some excellent cast net throwing skills :o)! I'm glad the net is getting some use. Hope you guys continue to have a good trip. Take care, Kathleen

    ReplyDelete
  3. Unknown18 October 2012 at 19:51

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    ReplyDelete

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