About Hiatodoris fellowsi (Kay & D.K.Young, 1969)
Hiatodoris fellowsi is a small species of nudibranch with an oval, firm, white body, black rhinophores, black gills, and white egg masses. It reaches a maximum length of around 51 millimeters. Like most nudibranchs, Hiatodoris fellowsi is a hermaphrodite, with separate external openings for its ejaculatory and vaginal ducts. It has a straight ejaculatory duct, paired with a tightly convoluted vas deferens. Its large, finely lobulate prostate gland lacks a prostatic duct. The spermatocyst and spermatheca are arranged semi-serially; both are ovate, with the spermatheca being slightly larger than the spermatocyst. This species has a long, loosely convoluted vaginal duct that opens into the spermatocyst. The uterine duct runs from the spermatocyst to a junction where the ampullary duct, prostate, and mucous gland meet. Hiatodoris fellowsi has a simply hamate radula, with teeth that measure between 75 and 450 micrometers long. The teeth curve at a wide angle, shaped like a makau (fish hook) with a small outer flange. Hiatodoris fellowsi is distributed across the Pacific Ocean, with recorded occurrences in the Hawaiian Islands, Henderson Island, Hachijo Island, and Lifou. It inhabits areas under shaded cliffs and ledges at depths ranging from 3 to 24 meters, and feeds on sponges.
