Planaria have model kidneys

Population Growth in Planaria

Planaria reproduce by transverse fission. Isolated worms increase in number exponentially, while social animals at the same density are inhibited in terms of numerical increase, but over a 25 day period undergo a larger increase in mass. Isolated posterior fission products reproduce faster than isolated anterior fission products. Regulation of population growth is independent of density over a ...

Rheotaxis in Planaria Alpina

Regeneration in Planaria

Inmetazoans, regeneration of lost body parts requiring the formation of a blastema is known as epimorphic regeneration. A blastema is composed primarily of two cell populations: an outer cell layer or ectoderm, derived from the epidermis that covers the wound surface after amputation/fission; and mesenchymal cells that proliferate and accumulate beneath this wound epidermis, eventually differen...

Temperature and Locomotion in Planaria

A consideration of the temperature characteristics or thermal increments for locomotion in Planaria shows that they agree essentially with those reported for certain activities of other animals (Crozier, and Glaser). A process with the lowest increment (micro = 7,000 to 8,000) assumes control of the locomotor rate at temperatures above 20-22 degrees ; that with the highest increment (micro = 18...

Population Growth in Planaria Dugesia tigrina (Gerard)

Planaria reproduce by transverse fission. Isolated worms increase in number exponentially, while social animals at the same density are inhibited in terms of numerical increase, but over a 25 day period undergo a larger increase in mass. Isolated posterior fission products reproduce faster than isolated anterior fission products. Regulation of population growth is independent of density over a ...