Olindias phosphorica is a species of jellyfish from the central Atlantic, and from the Mediterranean Sea, belongs to the philum of the Cnidarians, to the class of Hydrozoans, to the order of Hydroids, to the group of Hydromeduses and to the suborder of Limnomeduses.
Despite appearances, that is, its small size and apparently harmless shape, it has tentacles of different sizes and very stinging. The jellyfish olindia is almost completely transparent and it is almost impossible to see it in the water without the mask. For this reason, together with Pelagia Noctiluca it is one of the most dangerous meuse in the Mediterranean.
The jellyfish Olindia is totally translucent in the daytime. At night, when the animal is more easily observable, it has a bioluminescence which gives it a blue-green hue, even the tentacles are bioluminescent.
Usually it lives in open water letting itself be carried by currents like all jellyfish, but this jellyfish has a strange behavior: sometimes it drops to the bottom where it remains motionless for some time, becoming practically invisible given its transparency.
On the edge of the root of the umbrella there are many tentacles. There are two types:
– primary tentacles: each radial canal faces a primary tentacle, which starts tangentially above the edge of the umbrella. Short, smooth and whitish, these tentacles are thickened at the ends in an adhesive button. At the base of each of the primary tentacles, thickened into a red bulb, there is a pair of white staticists. The number of primary tentacles can reach 60.
– the secondary tentacles: in the small depressions located on the edge of the umbrella the secondary tentacles take place. Longer (several times the diameter of the umbrella in full extension) and transparent, these tentacles are full of many batteries of clearly visible cnidocytes (prickly cells); their end is without the adhesive button. The number of secondary tentacles can reach 120.