About Antiopella cristata (Delle Chiaje, 1841)
Antiopella cristata (Delle Chiaje, 1841) is a semi-transparent nudibranch with an oval outline. Its body color is cream or light brown, and it reaches an adult length of approximately 7.5 cm. The head bears short oral tentacles. Its numerous lateral cerata have a smooth surface and an inflated shape. A thin, brown central digestive gland lobe is visible through each individual ceras; these gland lobes divide into many terminal branches at the tip of the ceras, a feature that distinguishes janolid nudibranchs from aeolid nudibranchs. The tips of the cerata are bluish-white and iridescent. The same white colouration that appears on the cerata also occurs in patches or lines along the bare central back, around the lamellate rhinophores, and on the metapodium. The rhinophores are joined at their bases by a swollen, wrinkled accessory caruncle. Both the rhinophores and the median sensory caruncle are slightly darker in colour than the rest of the body. This species has been recorded from Norway in the north, southward through the British Isles and the French Atlantic coast. It has also been found in Moroccan waters and the western Mediterranean Sea. It inhabits calm, clean water at depths up to 40 metres, living on hard substrata in the sublittoral zone.
