Dehydras

Dehydras are a fictional genus of freshwater cnidarians described in speculative biology and science fiction. The name derives from dehydration, reflecting claimed adaptations to drying environments. In these narratives, dehydras occupy a position similar to real hydras but possess dehydration-tolerant traits that allow survival in ephemeral waters.

They are typically depicted as small polyps with a cluster of tentacles surrounding a central mouth, roughly a few millimeters to a centimeter in length. The body is described as flexible yet resilient, capable of rapid contraction and regrowth, and possessing a simple, sac-like gastrovascular cavity.

Ecology and distribution: Dehydras are said to inhabit temporary ponds, seasonal wetlands, and margins where water availability fluctuates. They reproduce mainly by budding, creating new individuals from the base of the parent polyp. During drought or desiccation, a specialized desiccoyst or desiccoid capsule forms, allowing the organism to survive in a dried state for extended periods. Rehydration resumes normal activity, and buds may separate to establish new colonies.

Life cycle and reproduction: The life cycle is simple, dominated by a polyp stage. Sexual reproduction is described in some variants, producing short-lived free-swimming offspring that settle as polyps. The depiction emphasizes plasticity and regenerative capacity.

Taxonomy and status: Dehydras are not recognized in real-world taxonomy and have no verified fossil record. They are used in fictional or thought-experiment contexts to illustrate topics such as desiccation tolerance and resilience in aquatic organisms.