Aplysia nigrocincta is common in the Marshalls if you look in the right places. They seem to prefer intertidal and very shallow subtidal reefs down to about 2 meters depth. We have found some deeper, often in groups, particularly in patches of Halimeda algae on the lagoon slope as deep as 20 meters. It varies somewhat in color, with the most typical color form shown in the first few shots below. Aplysia nigrocincta was first reported in the Marshalls from Enewetak and Kwajalein Atolls as Aplysia parvula by Johnson & Boucher (1984).
A circular piece of the yellow brown shell is visible between the parapodia just right of center in the photo below.
This "face" view illustrates why these are commonly called sea hares.
This sea hare has also been seen at Majuro (below) by Ken Cone and Beth Van Zummeren.
This species also comes in a dark brown to black form, sometimes with white to yellowish spots.
This black form looks startlingly similar to the black form of the Hawaiian species, which has been determined by Golestani et al (2019) to be Aplysia elongata.
Created 27 January 2007
Updated 16 November 2021