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. :-)

Sunday, 4 July 2010

Day 19

Today we caught some fish in a reservoir. The day didn’t start very well as we didn’t find any fish in the market and by 10 we were still empty handed. We finally found a little reservoir and local owners who allowed us to set some traps. A couple of hours later the first two traps were empty, the third one had 5 fish and the last one had 24 fish! Hurray.
Yahui originally made a deal with the local owners that he would buy the fish and stay at their place for lunch but for arguments that would escape any wise western scientist he refused to pay them and went back to town for lunch…I think he was keen to get a specific type of soup that he spotted there last night.:-)
Anyway now we are back on the road trying to catch up with lost time. There is a feeling in this expedition that we are always running after time, a sort of race against ourselves and the demands from referees when we will try and publish the results. I can see the comments, you have only caught 30 fish which is on the low side or why didn’t you get another sample from that location etc…
Today the weather is cooler with a 29 °C max and no sunshine. We have a mutually interested discussion with Yahui on the need to have free access to the internet. His view is that internet freedom is dangerous and a good example is when you see student s using guns in America for mass killings on university campuses. For example, in China you have a limited access to international news and “live” radio programmes are broadcast with 12 hour delays… Not for me to judge.
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1 comment:

  1. Anonymous4 July 2010 at 12:03

    !Viva Espana! What a thrilling match! My behaviour was not exactly what one would call as appropriate of a profesisonal female but adrenalin levels were too high. Great to read the news that you post, whether they are good or not so good. Keep spirits up and posting great pictures! All the best Genoveva

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