Ancula lentiginosa
Not much is known about this little cutie, but every once in awhile someone comes across a specimen along the coast of Southern California. Like it’s sister species,Ancula gibbosa (previously Ancula pacifica ), it has a slender "goniodorid" shaped body with three extra-branchial and extra-rhinophoral appendages adjacent to its gill and rhinophores, respectively.
It’s infrequent sightings may be due to it’s very broken up geographic and depth ranges. Behrens (2004) reports that the range of this species is extended from Marin County, California to Bahia de los Angeles, Mexico, southward to Islote Mosquera, Isla Galápagos, Ecuador. Additionally, while usually found in diver depths, this species has also been collected on several occasions in 2300 ft of water off San Diego, California.
This dorid nudibranch likely feeds on the colonial kamptozoan (or entoproct), Barentsia sp. Entoprocts, or Kamptozoans, as they were once referred to, are microscopic moss-like colonial animals. Divers rarely notice them, and in fact I am not even aware of a photograph of an entoproct colony. Trapania velox is also thought to feed on entoprocts, however this has not been confirmed. Trapania is normally found on encrusting sponges, but like Ancula, the morphology of their radula is grossly different from that of other sponge eating dorids, and entoprocts commonly grow on and within these sponges.
Drawing of an entoproct colony.