Table of Contents
How do planarian flatworms move?
Planarians move by beating cilia on the ventral dermis, allowing them to glide along on a film of mucus. Some also may move by undulations of the whole body by the contractions of muscles built into the body membrane.
How do Planarians move and feed?
A bilaterally symmetrical animal moves with the anterior forward and crawls on its ventral surface with the dorsal surface upward. The planarian eats small animals or larger animals that have died. The planarian is a carnivore. To ingest (swallow) food, the planarian extends its pharynx out of its mouth.
Why do Planarians move away from touch?
Based on prior literature, it was hypothesized that the planarian would exhibit negative phototaxis (movement away from source of light), tactile sensitivity resulting in movement away from source of touch, and a complete regeneration into two planarians approximately 5 to 6 days after decapitation.
What structures do planarians use for locomotion?
Cilia, Part B Planarians are free-living invertebrates that employ motile cilia for locomotion. Specifically, cilia that populate the ventral epithelium of the planarian body are highly conserved, with a 9 + 2 axoneme and a full complement of inner and outer arm dynein motors.
How do platyhelminthes circulate?
Flatworms do not have a circulatory system in the usual sense. There is no need for a special circulatory system as a human has because the flatworm doesn’t breathe with lungs and doesn’t need to transport oxygen around its body. The flatworm simply diffuses oxygen via its skin.
Does a planarian have a Coelom?
The spade-shaped head has two eyes and sometimes tentacles. The tail is pointed. The mouth is on the ventral, or lower, side, often more than half-way toward the tail. A body cavity, or coelom, is absent.
How do planarian survive without circulatory system?
There is no need for a special circulatory system as a human has because the flatworm doesn’t breathe with lungs and doesn’t need to transport oxygen around its body. The flatworm simply diffuses oxygen via its skin. This occurs wherever it may need the oxygen.
Why do tapeworms have hooks?
Tapeworm oncospheres have hooks (H) that help them penetrate the intestinal wall of the first intermediate host.
What can planarians do and how do they do it?
Planaria eat living or dead small animals that they suck up with their muscular mouths. Food passes from the mouth through the pharynx into the intestines where it is digested by the cells lining the intestines. Then its nutrients diffuse to the rest of the planaria.
How does a planarian eat?
Planaria eat by extending their pharynx out and sucking up food. Here they can be seen eating boiled egg yolk. Planaria are studied for their remarkable regeneration abilities. If you cut a planarian worm into several pieces, each piece will regenerate into a new worm. The magnification is seen in the bottom right hand corner of each shot.
How does a planaria reproduce?
Planaria can reproduce asexually by fragmentation. They split into fragments, which develop into adult planaria. Planarians exhibit a form of asexual reproduction known as fragmentation. In this type of reproduction, the body of the parent breaks into distinct pieces, each of which can produce an offspring.
How does Planaria eat?
Planarian feeds on the decayed and small animals, because it is zoophagous (even it has no teeth). It likes the protozoans as flagellates, ciliates, sporozoans, and nematodes. This kind of food is sucked up by the mouth and goes through pharynx into the intestine.