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.
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 covers a planarians body to aid in it’s movement?
Planarians move like other worms do. They swim in a wave-like motion of their body. Over solid surfaces they glide over a slime layer of mucus that they secrete, propelled by the cilia that cover their body.
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 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.
How do Platyhelminthes breathe?
Flatworms are small, literally flat worms, which ‘breathe’ through diffusion across the outer membrane. The flat shape of these organisms increases the surface area for diffusion, ensuring that each cell within the body is close to the outer membrane surface and has access to oxygen.
Does planaria move toward or away from food?
Does the planaria move toward or away from the light? Planaria exhibits negative phototaxis, moves away from the light. Planaria senses the presence of food by tasting the water around it for compounds released by nearby food using its auricles which are chemoreceptors. Planarians lack specialized gas exchange organs.
What do planarians use to attach to a host?
They have no digestive or nervous tissue. Attachment to the intestinal wall is by a scolex, a structure that contains hooks and suckers. The segments (proglottids) each contain male and female reproductive organs. Eggs are fertilized from sperm, which often come from other proglottids of the same individual.
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.
Do planarians have muscles?
The body-wall musculature of adult planarians consists of intricately organized muscle fibers, which after amputation are regenerated rapidly and with great precision through the proliferation and differentiation of pluripotent stem cells.
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.