No one even knows the true number of species in the world, they say.

The total number of species in the order is now about 1300.

The area is home to a very large number of marine species.

However, the true number of species is difficult to determine.

However, there are a much greater number of "small" species in any given area.

The area is covered in a number of native species.

The number of described species has been estimated at 1,899,587.

A number of species have been discovered and described recently.

The number of species is relatively small and around two hundred.

The area has a number of species found nowhere else.