Description
Hydras resemble tiny, delicate, elongated sea anemones. They have a columnar or trunklike body, which is structurally a bag (with the mouth at the top). The mouth is rimmed with several long tentacles. Hydra bodies are only two cell layers thick. A sticky secretion at the “foot” enables hydras to cling to a surface. Hydras can glide slowly on their foot, or they can bend over and turn slow-motion somersaults. Colors vary with species; they can be gray, brown, tan, cream-colored, green, orange, whitish, pinkish and “clear.”