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 29 June 2010

Day 15



We have decided to catch up with our schedule and we left Guilin at 9h00 and arrived in YueYang at 8h00. We are all exhausted by the journey. Our new driver Ya is ok although with a less agressive style than Haito. He is fairly young and left his wife and 6 months old baby at home to share the rest of our journey. On our way we stopped at a 100 year old canal linking the Yangtze river to the Pearl river system. Near the canal there was an old woman selling skewers of bitterling and topmouth gudgeon, Bernd and Rob tried...I bought some live ones for genetic analysis! Tonight, on our way to find a place to eat, I noticed a tank full of topmouthin a restaurant, I tried to buy some more but the negotiation with Yahui and the restaurant owners ended up with us having dinner there. She grabbed a live grass carp from the bottom tank that she scaled and cut on the pavement before putting it in a sauce made of chili peppers. This province is well known for very hot hot food and it didn't disapoint us. We all prayed hard for our stomachs to handle it. Then I realised that all restaurants were selling topmouth would you believe. I am not sure who commented that the French and Chinese shared a passion for food and I agree with that but I don't normally eat my subject of study unless it's a sea bass!

This part of China is the birth place of Mao and communism. It is also extraordinary to see giant cities coming out of the ground like mushrooms. The scale of development has no comparison with anything I have seen before. It is difficult to imagine that there will be enough jobs for everyone wanting to live in these new cities? A lot of people here think this is a big bubble. The only thing I know is that in a decade this will be a completly different country.


Any captions yet on the raincoat picture?? Come on I can think of few ;-0 Perhaps you would like to see Rob in his tango man outfit??

Rudy
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