Monday, 26 March 2012

Ovington and the River Itchen - 24th March

Today we ventured a little away from Four Marks, down to the river Itchen at Ovington.  The place was packed with people taking the chance to stroll along the river and then return to the Bush Inn for lunch or a drink.  This was precisely our intention, and we did not intend to walk far, but it was enough to see something unusual.

With the lack of rain the river was low,and not too fast flowing.  As a result there were lots of trout visible in the water, and they were easy to watch as we stood on the bridge.  The footpath splits the main river from a side channel, and as we stepped off the bridge I noticed an eel like fish in the gravel area.  The size was a concern though it was only about 10 cm long which was much to small for an eel.  As I looked closer I could see that the fish was picking up small stones and flicking them away in an effort to dig down into the gravel.  This was clearly no eel, and I vaguely remembered Lamprey.  As we watched them it became clear there was in fact two, and they were both moving the stones, some quite big in comparison.

As usual when confronted with something like this I did not have the best camera, but I did manage a record shot.  If you look closely you can see the two fish one close close to the vegetation, the other off to the left.

These are in fact Brook Lamprey, and are special to the Itchen, but not something that is easy to see.  These animals have a very interesting life cycle, with the spawn hiding down into the silt in quieter areas of the river, and filter feeding on detritus.  Unlike other Lamprey species they do not spend time in the sea, and are not seen attaching themselves to other fish.  Typically they are only active at night, but will come out during breeding.  As they develop into the adult fish, they metamorphisise with the digestive tract degenerating, and the sucker-like mouth developing.  The adult phase is all about breeding, the act that we were witnessing today, after this is complete they will die, and their young will start the process all over again.  If you want to see what we were seeing then follow this link to the BBC web site where there is very good small video by Simon King on the Brook Lamprey.

Further along the footpath, Helen and Katie saw a Water Vole, unfortunately all I could see was it's latrine, but is good to know they are present on the river here.  As we waited for the vole a Comma butterfly put in an appearance, and did give me the opportunity to photograph the first for the year.

Back in the garden of the Bush Inn a Peacock flew through.

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