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. :-)

Thursday 24 June 2010

Day 9


We didn't manage to get a sample today which is frustrating but that's the way it goes. The roads here are flooded and yesterday we were blocked on country roads as lots of trucks & cars went off the road into ditches and had to be rescued. The rivers are chocolate brown. I can't stand the market anymore, it is so disgusting and animals are so badly treated that it is difficult to eat anything after seeing it. Today we stayed in a very good hotel and they had...english tea & coffee with...cakes! Yippee! Bernd and Rob are facing a tense evening as England and Germany will now be playing each other on Sunday!
In response to Irene's comment, I anticipated the defeat of the blues during the first round which is why I organised the sampling during the world cup. It helps me save face, something I am learning from my Chinese colleagues! Imagine going back to the office after loosing against both Mexico & SA :-(
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1 comment:

  1. Anonymous24 June 2010 at 11:41

    Rudy, you are really a wise man! I only hope, you will not have two excursions by monday morning!!
    If Germany wins and Bernd gets too excited, just mention one name: CORDOBA ;-))

    best wishes, Irene

    BTW: I have TMG for you, too

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