About Bonellia viridis Rolando, 1822
Bonellia viridis Rolando, 1822 displays extreme sexual dimorphism. Females of this species have pale to dark green bodies that are round or sausage-shaped, reaching 15 cm in length. Females live on the seafloor at depths between 10 and 100 metres, where they conceal themselves by burrowing in gravel, hiding in rock crevasses, or occupying burrows abandoned by other animals. Under their bodies, females have two anchoring hooks, and an extensible feeding proboscis that can grow up to 10 times the length of their body. Bonellia viridis is primarily a detritivore, but it also feeds on small animals. Males of this species are rarely observed. They have flat, unpigmented bodies that only grow between 1 and 3 mm long; their bodies are almost entirely composed of reproductive organs, with no other significant structures developed. Males live on or inside the body of a female. This species has a wide distribution, and is found in the north-eastern Atlantic Ocean and the Mediterranean Sea.
