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, 20 June 2010

Day 5

At our last stop we had some trouble finding a decent sample of fish. However, the interesting thing is that with what we have collected we have clear phenotypic differences. Some fish have a very large dark band on the side which goes right through the tail. Genetics will tell us if it is only a phenotypic difference. On the way to our next site we had a flat tyre (it had to happen when you see the state of some of the places we're going) and I am now blogging from a garage in Nanjing a large city on the lower Yangtze River (the capital of the south ). As soon as the car is fixed we are heading off further south.


Bernds stomach is starting to complain about soup and stir fry for breakfast (and no coffee!!!!!)
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2 comments:

  1. Yuval Rabin21 June 2010 at 01:52

    Hay Rudy,
    I am really happy for you that you are in a unique trip like this.
    I would love to be there with you looking for fish as you know me.
    take care over there in china,
    and by the way I caught a mullet on the shore
    and 9 denises!

    Love from eilat,

    Yuval

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  2. Anonymous21 July 2010 at 06:12

    Shalom, How r u..Last time we paid 50 NIS for a Kg Fresh Denis in carmel and 80bucks for a roasted one. 9 denises are a good beginning..to make up your return fair...I am confident your children won't go hungry...but take care of shark..whales..it is still mediteranean there...Yona still looking for a friend...c u soon..missing u love.God bless you

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