Thursday, March 05, 2009

SALMON CHANTED EVENING (You might meet a strange fish)

The largest entirely freshwater fish known to science is the wels catfish (Silurus glanis). The largest specimen of this remarkable creature ever caught was fifteen feet and has even been introduced to British waterways, most notably by the massively eccentric 19th Century Naturalist Frank Buckland. However a quarter of a century ago, came the first tentative reports of a beastie, which if it exists will, in comparison, make the fearsome European Catfish seem like a veritable minnow.

In 1985 Xinjiang University biology professor Xiang Lihao led a party of biology students to Lake Hanas in north west China`s Xinjiang Autonomous Region. The expedition was to evaluate the lake`s potential as a wildlife reserve.

The lake has long been considered as one of China`s greatest natural resources. The name itself means `Lake Beauty` and the mountain lake is surrounded by lush pastures which in summer are a riot of wildflowers and deep forests teeming with rare and beautiful wildlife. However the lake has a more mysterious side. According to a website maintained by students in the area the colour of the water appears to change with the seasons…

“for this reason, people also call it"the lake of changing colors".this is one of its mysteries.the people living around the lake have also found that there are some "lake monsters" in the lake. they reported hearing a large "bang" in the lake while watching a very high water column shooting out of the lake. it is still unclear what on earth makes this "trouble"in the lake.”

However, as far as we know, the eminent professor was searching for more conventional wildlife when he made his trip. However on July 24 the Professor and his charges saw several monsterous fish. One of the students was observing the surface of the lake from a wooden watchtower which had been built several years earlier when he saw some immense objects moving slowly beneath the surface of the water. They were resddish in colour and according to my friend and colleague Dr Karl Shuker their heads, fins, and tails all clearly visible. He estimated that their heads were 3 feet across. The next day he took several colour photographs of the fish. One aligned itself parallel to the bank between two lakeside trees. Later measurements of the distance between these trees allowed the scientists to gauge its length at 33 feet.

Two days later they attempted to catch one of these remarkable fishes. However neither such succulent baits as sheep legs or wild duck were effecacious in luring one of these monstrous creatures onto a hook, and therefore into the record books.

Two years later in 1988, a further investigation of the lake was carried out after local fishermen again reported seeing three of the giant fish with a slightly less remarkable length of thirteen feet. An in depth investigation using hovercraft, and aerial recconnaisance was carried out, but again no specimens were secured, and as one wag once put it “what`s hit is history – what`s missed is mystery”!.

So, if these fish do exist what on earth are they?

In appearance at least they appear to be salmon like in form. Therefore the salmon family (salmonidae) would appear to be a sensible place to start our investigations.

The largest salmonid in the world is the King Salmon (Oncorhynchus tshawytscha) which is found in the rivers of Pacific North America. However, another large salmon (Hucho taimeni) which can reach a length of 6.5 feet – a not inconsiderable fish (though miniscule compared to the giant fish of Lake Hanas does live in the area. Although most salmonids migrate to the sea as an integral part of their life cycle, some species are entirely landlocked including some close relatives of the enormous King Salmon, so the idea of an enormous landlocked salmonid may not be as ridiculous as it may first seem.

The concept of landlocked salmonids growing to an enormous size is not a new one. There are many accounts in British zoological folklore of particularly large salmon of the normal UK species – Salmo salar - which have become trapped in landlocked lakes and pools and have achieved an immense size. However the largest known British salmon was a mere 66lb and was caught in Scotland in 1922.

Without, for one moment, intending any disrespect towards the good proffessor, one of the biggest potential problems with the existence of such enormous salmonids is the small matter of their swim bladder According to zoologist Richard Freeman, this organ seems to be only effective up to a certain body size which has, to date, proved an effective limit to the size of fish species that rely on the swim bladder for their buoyancy. Sharks and rays have no swim bladder which is why the largest fish found in the oceans of the world are from this group. If the fish of Lake Hanas are indeed salmonids then they would presumbly have swim bladders, and this presumably means that they have either developed an effective way of uitilising their swim bladders despite the increased size, or that they have evolved another method of buoyancy control entirely.

The final qustion that has to be answered is the relationship (if any) between these enormous fish and the other putative monsters of the lake. Unfortunately the account that we have managed to discover tells us next to nothing about the nature of the Lake Hanas monster. Lake monsters have been reported from a number of Chinese lakes, most notably Lake Tianchi on the border between China and Korea, but the description of “a large "bang" in the lake while watching a very high water column shooting out of the lake.” Is so vague that it could really refer to anything.

One thing, however is certain. As far as we have been able to ascertain, the last expeditions to investigate the events at Lake Hanas took place in 1988, and as far as we know, no-one has been back since. This is a great pity, because this beautiful lake is the site for at least two zoological mysteries, and deserves to be given at least as much attention as is given each year to Loch Ness. Watch this space.

1 comment:

  1. Jon,
    is it not possible that these fish after a certain age started using oil in the swim bladder similar to the way sharks do?
    Just a thought.

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