Ключевые слова: animal, biology, cell, coelenterate, contrast, differential, freshwater, hydra, hydras, hydroid, illustration, laboratory, life, light, macro, metazoa, micro, microbiology, microorganism, microscope, model, morphallactic, nature, nucleus, organism, photo, regeneration, reproduction, research, school, science, tentacles, training, university, vulgaris, water, white, wildlife, zoology,