This small specimen of Murena Helena was found on a bed of rock and Posidonia at Capo Pecora in Sardinia. Despite being a predator, this moray shared the den with other small fish, like some young specimens of Castagnola Nera Chromis Chromis easily visible thanks to their intense blue livery.
In the video we can see not only sea urchin and red sponges but also the Bonellia viridis, a marine invertebrate of the Bonellidi family that lives in the Mediterranean seabed. The female of bonellia is green, the body is formed from an oval part (of about 6 ~ 8 cm in length) and a long proboscis (visible in the video) which at the end divides into two, which secretes a green pigment, the bonellina, which allows it to paralyze small animals that are then eaten.
The strange aspect of this species is that the male remains in a larval state (even if sexually mature) from 1 to 3 mm in length and spends the whole life cycle inside the female.
The moray in this case does not seem bothered by the poisonous marine worm, despite being small in fact it does not fall between the preys of the Bonellia viridis