Nemerteans can have from two to 250
pigment-cup eyes. The one above has two eyes, and above right six eyes.
There are two Classes; the Anopla with a
simple proboscis; and the Enopla with a more complicated proboscis armed
with stylets (see Prostoma rubrum above right, which in some can deliver toxic secretions), and Tetrasemma sp. a mud-dwelling species on the right.
It can eat prey wider
than itself, and wide prey shows up as a bulge in its body which gets smaller
as digestion proceeds and the prey passes further down the body.
worm, Lineus sp., is perhaps one of the more commonly known
Nemertea. It looks just like its name suggests, and can be as much as 10 metres
long. It is usually found entangled under rocks and crevices, and easily breaks
apart if you try to untangle it.
Regeneration from the fragments is simple, and
is an alternative means of reproduction for this worm.
Many are brightly coloured.