Big Picture’s posterous

Looking  like giant leaves floating in the sea thousands  of Golden Rays are seen here gathering off the  coast of Mexico.

The  spectacular scene was captured as the  magnificent creatures made one of their biannual  mass migrations to more agreeable  waters.

Gliding  silently beneath the waves they turned vast  areas of blue water to gold off the northern tip  of the Yucatan Peninsula .  

Sandra  Critelli, an amateur photographer, stumbled  across the phenomenon while looking for whale  sharks.  
She said: 'It  was an unreal image, very difficult to describe.  The surface of the water was covered by warmand  different shades of gold and looked like a bed  of autumn leaves gently moved by the  wind.  

  
'It's hard  to say e xactly how many there were but in the  range of a few  thousand.

  

  
'We were  surrounded by them without seeing the edge of  the school and we could see many under the water  surface too.  

'I feel  very fortunate I was there in the right place at  the right time to experienced nature at his  best.' 
Measuring up to  7ft (2.1 meters) from wing-tip to wing-tip,  Golden rays a re also more prosaically known as  cow nose rays.  

  

  

They have  long, pointed pectoral fins that separate into  two lobes in front of their high-domed heads and  give them a cow-like  appearance.  
Despite  having poisonous stingers they are known to be  shy and non-threatening when in large  schools.  
The  population in the Gulf of Mexico migrates, in  schools of as many as 10,000, clockwise from  western Florida to the Yucatan  .