All crustaceans have segmented limbs and a hardened external skeleton. This Macrothrix is similar in shape to the common Daphnia, but is slightly larger, has more limbs and larger antennae. The Macrothrix also has two separated and distinct compound eyes. The heart, which was visible along the upper back behind the head, could be seen beating in the microscope. This image is at 400x magnification showing that the Macrothrix is about twice the size of a Paramecium. Back To Image Index Page