I think it is a pot belly seahorse. found around the nets at Manly
Is this a Flatidae nymph, it looks oddly developed but it does have the fibreoptic bum.
In the Chinese Friendship Garden koi pond.
This shot of a Sea Horse was taken at a depth of about 7 metres in Clifton Gardens, Chowder Bay, Sydney on 20th January 2011.
I used my Nikon D200 digital SLR on manual settings with a 60mm Nikkor lens and two Inon Z-240 strobes on low manual settings. ISO 200, aperture F14, shutter speed 1/25th, Exposure Compensation -0.7.