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. :-)

Saturday 10 July 2010

Day 26

Whooah…morning market today was like a bad hangover, in silence like three ghosts (we left Yah to sleep longer as he has to drive all day) we wandered the road of Kangping in search of the colourful parasols indicative of the market. When we arrived a local fisherman had 8 little topmouth gudgeon waiting for us but said that we should have come at… 4 if we wanted to get a chance to get any topmouth. Very funny.
After breakfast we headed up to the local abandoned reservoir, which was a stunning nature reserve with lots of mature ponds (I took a sample of water + sediments for Genoveva) and set up our traps following the advice of a local angler. When we asked if the fish was present and where should we fish, he said yes there are a lot and pointed out to a location as far from where he was as possible. After an hour fishing, and no fish in our traps we realised that all around the world anglers are all the same!!
We headed up for a smaller reservoir further up the catchment, there we had more luck, we met local fishermen who emptied their traps for us and that was enough for us to get a sample. All done with good heart with no charge, no negative feeling pure altruism something we have forgotten in our part of the world. The lake was riddled with maze traps, which are illegal in China but that everyone uses with a general consensus that it is illegal. This is the most amusing side of China and Chinese people who are full of complexity and contradictions which could at first be unsettling for our rational culture but which is in fact very refreshing as it allows the complexity of life and its daily contradictions to be integrated without having to confront or resolve them aggressively. Their society is full of subtlety and poetry, far from our ‘communist state’ stereotypes and we have a lot to learn from it.
This is a good occasion to introduce some Chinese sayings such as "Like climbing a tree to catch a fish" (waste of time) or" like asking a blind man for directions" (another waste of time) or one well suited for our leaders, "a new bottle filled with old wine" (a superficial change). Enough of that, I am being unfair with our leaders as I look at the sky from the bottom of a well (anybody know what that could mean?).
Lunch time in a local restaurant and guess what we had, fried topmouth gudgeon! Not bad but I will stay with sea bass when I return if you don’t mind.
That's it, we are now heading toward Chéngdé a town three hours from Beijing. Used to be a summer welcome retreat from Beijing for several emperors starting with the first Quing dynasty. I am not sure if we will have time to look at it but there is apparently a jaw-dropping colossal statue of Guanyin.
Genoveva and Rafa good luck for the final on sunday. It is broadcast here at 2.30 am but we will be watching...hopefully with both eyes open :-)
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