Hydras and Volvox 🐙These graceful and alienesque critters are named Hydra viridissima and are among the main representatives of freshwater Cnidarians, a primitive animal group that includes jellyfish, corals and sea anemones! Hydras are found in all continent across the Earth except for Antarctica and are one of the simplest multi-cellular forms of life known to humanity. Their green colour is due to a symbiotic relationship with Chlorella, a green algae that lives inside the hydra’s cells producing sugars from sunlight and giving some of this precious energy to the hydra in exchange for protection against predators and a well-suited environment! This relationship is mutualistic, meaning that they both benefit from the partnership. This source of sugar can be critical for hydras, especially when they can’t find anything to eat!There are aout 11 000 different species forming the Cnidaria phylum and all of these species are characterized by specialized cells called cnidocytes. These stinging cells are most abundant on the tentacles and when triggered by a predator or a prey, they explosively unleash their content made of a nematocyst equipped with barbs, spines and a long filament. This nematocyst is what makes Cnidarians effective predators by injecting a paralyzing cocktail of neurotoxins or by entangling their preys. Can you see small spikes on the tentacles? These are the cnidocils! When triggered by a prey, they discharge the nematocysts, which are visible as small circles near their respective cnidocil 👀 Freshwater hydras prey on small invertebrates like crustaceans, annelid worms, insect larvae and small larval fish.Video taken with my iPhone mounted on a BA310E Motic microscope with an @ilabcam adapter 🔬#biology #microscope #microscopy #invisible #aquarium #biologia #microscopio #science #sc#Science#pond #water #green #algae #jellyfish #sea #biologist #fyp #lake #fypシ #fypシ゚viral #tentacle #weird #relaxing #relaxingvideos #shorts #student - @tardibabe