Radial Symmetry
Hydras are acoelomates.
One type of symmetry is rotation. The second type of symmetry is translation. The third type of symmetry is reflection.
Bilateral Symmetry
Hydras exhibit radial symmetry as their body structure is organized around a central axis, allowing for multiple identical segments around that axis, which is evident in their tubular shape and tentacles extending outward. In contrast, planarians display bilateral symmetry, characterized by having a distinct left and right side that mirror each other, along with a defined head and tail region. This difference in body plan reflects their ecological niches: hydras are often sessile and interact with their environment uniformly, while planarians are more mobile and exhibit directional movement.
Bilateral symmetry
The hydras are gone.
Bilateral Symmetry
Bilateral symmetry.
Bilateral symmetry.
Bilateral symmetry
Bilateral Symmetry
Bilateral symmetry