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. :-)

Monday 5 July 2010

Day 21

Started the day well with a good sample of fish from Cangzhou in the bay of Bo Hai (south east of Beijing). We left early but got caught in one of these gigantic traffic jams. Our driver decided to take the motorway the "wrong way" to try and go back to the previous exit. It was the most frighting 15 minutes for a long time! I even took a shot of a giant green truck passing by... Anyway we are all alive and back on track although we have lost 3 hours of our schedule which means that tonight we are only in Xingcheng, a local coastal town not far from the North Korean border. The good news is that we had time to stop and see the Great wall of China, it is Gate number 4 right at the start of the wall (near Qinhuangdao). With the mountains as a backdrop and the tourists gone it was a very relaxing moment.So tonight we stayed in this little hotal on the coast and I am getting bitten by a hoard of mosquitos! Tomorrow we should be reach Dandong on the North Korean border. We will try to get some fish from there as it is a small coastal river flowing to the pacific ocean. From a scientific point of view it is interesting as all these little coastal rivers and the Amur basin used to be connected before being geographically isolated at a later stage. Today the temperature rose up to 41oC with a beautiful blue sky but in the car it was sauna for all despite our air conditioning being on at full blast. On the menu tonight there was dog and other exotic meals...I have to say it will be relaxing back home to go to dinner without having to be apprehensive...unless it is my wife cooking (he he, just joking she is the best cook in town!).
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1 comment:

  1. Anonymous6 July 2010 at 09:31

    I dont know whether it helps, but here (Austria) mosquitos are also just HORRIBLE. I really envy you for seing all these great - and small - things.

    Dont cross the border to North Vietnam tomorrow!

    kind regards
    Irene

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