The anemone Exaiptasia diaphana, known until recently under the name Aiptasia diaphana although it is not currently an accepted name, is a species belonging to the Aiptasiidae family, within the Actiniaria order. It inhabits the very shallow (up to 10 meters deep) and warm waters of the Mediterranean Sea and the eastern Atlantic Ocean. It is a species that tolerates not very pristine waters, and is frequently observed in ports.
The body of Exaiptasia diaphana is relatively small. It consists of a fleshy foot of about 3 cm in diameter and 5 cm in height, from which at the top we find a disk of 3 cm in diameter from which arise up to 160 thin, conical, translucent tentacles with a slightly whitish base. These tentacles are arranged in 4 to 5 concentric rings. The body of this anemone is yellowish-brownish or brownish-greenish in color.
Exaiptasia diaphana feeds on invertebrates and small fish, which it captures thanks to stinging cells present in its tentacles. These cells, the cnidocytes, have a substance that paralyzes their prey. Despite this food source, Exaiptasia diaphana also has in its tissues zooxanthellae algae in symbiosis, which also provide sugar compounds on which the anemone feeds.
The reproduction of Exaiptasia diaphana can occur both sexually and asexually depending on the conditions in which they are found. In summer, the most commonly observed form of reproduction is asexual, whereby a specimen genetically identical to the predecessor is generated by gemmation.
It is common to find specimens of Exaiptasia diaphana forming large colonies of individuals, a feature that will allow us to differentiate this species from Aiptasia mutabilis (solitary and slightly larger species). Another species with which it could be confused is Bunodactis verrucosa, although the latter is clearly differentiated by the presence of striated marks forming transverse rings that run along its tentacles.
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