Images Dated 11th August 2004

COMMON FROG - on lily pad in pond

JD-8844
COMMON FROG - on lily pad in pond
Rana temporaria
John Daniels
Please note that prints are for personal display purposes only and may not be reproduced in any way

© John Daniels/ardea.com

Amphibian, Amphibians, Amphibians And Reptiles, Europe, European, Frog, Frogs, Liiles, Lily, Pond, Ponds, Single, United Kingdom, Water Lilies, Water Lily, Wild Life

Cultured freshwater pearls

Cultured pearls from freshwater mussels. Pearls are accretions of nacre (calcium carbonate) secreted by certain oysters and mussels. The presence of a foreign body (such as a parasite or a grain of sand) within the shell triggers the secretion of nacre by the mollusc's mantle. Thin layers are deposited on the irritant particle and, over several years, a pearl is formed. Although commercially valuable pearls are obtained from freshwater mussels and oysters, the precious pearl comes from species of Margaritifera oysters found in tropical oceans. Cultured pearls are cultivated by inserting fragments of clam shell into the shells of farmed mussels and oysters

© VAUGHAN FLEMING/SCIENCE PHOTO LIBRARY

Landsat photo of River Nile

Landsat photograph of the River Nile as it snakespast Luxor (grey area on right bank, one third ofthe way up the image). The major features are thedense bands of cultivation which cling to thebanks of the river through a highly-developedirrigation system, assisted by the Aswan Dam whichcurbed the spring floods. The loop in the centreof the river contains the Valley of the Kings. Butdrifting sands have concealed many of thestructures of Ancient Egypt

© Earth Satellite Corporation/Science Photo Library