The majority of sexual reproduction is through cross-fertilization (where both individuals fertilize each other).

If a flatworm is starved it is capable of shrinking to hatching size and when fed it has the ability to grow back to its original size.įlatworms are hermaphroditic (having both male and female sex organs) and they typically reproduce both sexually and asexually. Small flatworms use waves of ciliary action for locomotion to glide over surfaces, whereas larger species use muscular movements of their entire body to creep, swim, twist or somersault along the substrate. Scientists can train flatworms to do simple tasks, such as finding water in a maze. When these flatworms are then cut in half, the new halves learn faster than the original.

However, if the animal is cut transversely near one end, say, separating a small piece of the tail from the rest of the body, the larger piece will grow a new posterior end, but the piece of tail lacks the capability to produce an entire new anterior end.įlatworms usually have one pair of direct or inverted cup eyes for detecting movement. If a flatworm is cut through the middle of the body (as it is in normal transverse fission), each half will regenerate the corresponding lost part.

Flat black worm