Crustaceans

Marine Crustaceans:
The best way to photograph crustaceans (and live molluscs and echinoderms) is fully submerged underwater as specimens that are half wet/half dry are really difficult to see the diagnostic characters.

Crabs
For fuller identification of crabs their needs to be at a minimum:
 * 1) a top view
 * 2) a front view showing the claws and eyes,
 * 3) an indication of size
 * 4) habitat in the notes.