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The London Freshwater Group site visit to Blo' Norton Fen (and adjacent sites)
which are managed by the Little Ouse Headwaters Project (LOHP) 
 
Detailed photos of species found on the day.
Photos and text by Adrian Chalkley.
All copyrights remain with Adrian Chalkley, www.boxvalley.co.uk
 
Anabolia nervosa
This was one of two species of caddis fly larvae found in the river Little Ouse by the road bridge.
 
 
 
 
 
Caenis luctuosa
This was the tiny mayfly larva from the scrape that was swimming slowly with a side to side serpantine motion. Anglers name is The White Midge
 
 
Dytiscus marginalis
A Great Diving Beetle. Spotted and then chased around Jo's Pond by Carl who was determined to catch it. The one he caught was a female but the one in the photo is male. (Look for the large round suckers on the front legs?) D marginalis is probably the commonest species.
 
 
Gyrinus substriatus
Two species of whirligig beetle were swimming around in the scrape, this one is the Common Whirligig
 
 
 
 
 
 
 

Notonecta maculata
This water bug, a water boatman or backswimmer was in Jo's pond found by Robert. I tend to call this the Speckled Backswimmer.

 

 
 
Planorbis carinatus
This is the Keeled Ramshorn Snail, which was in Jo's pond.
 
 
 
 
 
Anax imperator
Larvae of the Emperor dragonfly, adults were seen at the scrape on Parker's Piece and at Jo's Pond. There were also moulted larval skins at the scrape but no exuviae. Showing they had bred but not proving they had hatched into adults.
 
 
 
Cloeon dipterum
This mayfly larva was also found in the scrape, one of the commonest in Britain. Anglers name The Pond Olive.
 
 
 

Haliplus sp. ruficolis group
Two species of Haliplus were common in the scrape at Parker's Piece. Some females cannot be identified to species and are just part of the larger ruficollis group.

 

 

 

 

Gyrinus caspius
The second species is this one, the Caspian Whirligig - flown a long way just to see Jo I guess! The photo shows it head on, you can see the two upper eyes and below the antennae the two lower eyes. (Really each eye is divided into two, one evolved to see in air one in water) You can also see the 'moustache' of sensory hairs which 'feel' ripples in the water surface to detect it's prey.

 

 

Sigara dorsalis
The scrape was full of Corixid bugs including this common one. Commonly called a Lesser Water Boatman.

 

 

 

 

Planorbis carinatus
Another view of the Keeled Ramshorn, to show the keel around the rim of the shell.