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. :-)

Friday 2 July 2010

Day 18

Day18
We visited the early market but as we thought their was no wild caught fish as local rivers are dried up. Then we went to the airport to drop Bernd and got stuck in a giant traffic jam. Xi’an is a huge city but they are currently building a town within the town for about an additional 350000 people (as much as Bournemouth and Poole together!). We have our eyes wide open and we can’t believe what we are seeing, it seems as though its from a bad science fiction film and difficult to imagine where the resources (i.e. water, electricity etc.) will come from. It is clear that conservation of natural  systems is not a priority and puts all of our occidental views into perspective…
The northen part of the country is poorer and it is clearly noticable when going through the different towns & villages. The soil is dry and there is a constant smog giving a yellow colour to the air and the surrounding landscape. The Yellow river is gone in this part of China making the sampling of our fish impossible. We will try to get out of this province asap as we have still a lot to do in the Northen part and the Amur river towards Russia. Then we will go down  to sample on the boarder with North Korea (the river is the border line). Tonight we stopped in Sanmenxia, a very industrial city which saw its glory years during Mao with one of the first large dam's built in China...not anymore.

Response to Rafa: I have to say that when Rob & Bernd play majong it's a bit fishy! As for Spain meeting Germany, no chance with the Messy & Tevez they will eat the Germans alive for breakfast ;-)

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