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, 21 June 2010

Day 6

Day five was frustrating as we encountered some difficulties collecting our fish. The time schedule between two stages is short giving us limited option but to do some intensive sampling. In addition we had our first flat tyre so we had to find a suitable garage in Nanjing (large city in central east China). This took us a good couple of hours but luckily I managed to hijack their computer to send a message!

We normally wake up at 5 am and go to bed at 12pm. Today was also a frustrating sampling day. After a lot of effort we have managed to get a decent number of fish for our future analyses but it means that we are now behind our schedule and had to stop 4 hours away from our destination. We have to accept the constraints of the terrain and local culture. This is when you realise that planning something on paper and delivering it is something different. I don't think I fully appreciated how large China is. So far we have only done about 2000km in 5 days. We are all sleeping in the car synchronised by Yahui's load snoring :-)
Otherwise, in terms of landscape the countryside has gone from wheat production (above the shanghai area) to rice production (below), going though intensive wood factories. It is reflected in the northen part being poorer than the shanghai province with more modest houses in the north and large mansions and private ownership of the rivers in the southern part. We have all travelled around the world in the past but still every moment is a moment of surprise with constant contradictions. It is absolutely fantastic. It is also funny to see Yahui, who in our last two stages could already not understand the local dialect and found it very difficult to communicate. Although people are all supposed to speak mandarin they still use their local dialect from valley to valley. Apparently it will become more noticeable tomorrow...

The children in the towns and villages we have been through react to us as my children react to mickey mouse in Disney world! It is a mix of fear and excitement, waving their hands well hidden behind their parents. Parents ask to have their photograph taken with us.

Otherwise we pass the time in the car discussing football. We are fed from time to time with an update by Yahui. Of course he stays neutral in a French-Anglo-German analysis of who should win the World cup...the French (hahah). We have heard that the French team were striking against the coach who sent Anelka back home (if we understood correctly) and we all thought that it could only happen to French players!

Tonight Rob is not feeling great as he has had a sore throat for the last few days and he has started taking antibiotics. Our driver has a stomach upset ( I was expecting that from one of us but so far we are holding tight).

After tomorrow we are going to enter the Southern Region and in response to the comment about the Chinese proverb, they say that in the south province they eat everything which flies except aeroplanes and everything with four legs except tables...tonight we went to our first dog restaurant (see picture). Luckily it is not kosher so not for me!
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1 comment:

  1. Anonymous22 June 2010 at 12:19

    Sorry, Rudy! France will not make it into the next round of the soccer-world cup. They were so polite to loose against the host South Africa. Germany is doing well, as usual (2nd in the group) and England is right now 3rd in its group.
    Your trip sounds fascinating.

    best wishes Irene

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