compare the snake and earthworm
circular muscles
the brain
Earthworms, along with other animals, are eukaryotic.
The planaria class is Turbellaria
planeriacomes under kingdom animalea
Yes, deicer salt can affect the movement behavior of earthworms. When exposed to salt, earthworms may avoid the treated areas to minimize contact with the salt, which can disrupt their normal movement patterns and behavior. Salt can also have a drying effect on the soil, making it less hospitable for earthworms.
sp refers to a planaria where the actual species is undetermined...or sometimes because several species of planaria have similar appearance or behavior and have been used in a study.
Usually a planaria regeneration experiment involves cutting the planaria into different parts. The head can be separated from the tail or the planaria can be cut lengthwise, etc. After cutting the planaria, it will be observed for few days noting how the organism regenerate its lost body parts. Read more on planaria regeneration on t he link provided below.
Planaria prefer dark environments
Earthworms require oxygen to breathe, and when soil is saturated with water, there is not enough air present for the earthworms to survive. The excess water limits the movement of air in the soil, causing oxygen levels to drop and suffocating the earthworms.
They will disturb the roots by their movement and so will restrict the growth.