This little Lamellaria (approximately 20 mm) was found in less than 2 metres of water in a murky, mud covered, broken coral and rubble zone in North Kihei, Maui.  This is an area where flooding washed tons and tons of toxic soil into the ocean during the winters of 2021-2023.  It’s amazing anything is surviving in there.  When first spotted it appeared to be feeding on some yellowish tunicate. But within a split second of acknowledging my presence, it immediately picked up its back and began moving, almost in a hopping motion.  At first I thought this was a Marsienopsis species due to its high ridges and tall features, but Cory Pittman pointed out that “the ridges in Marseniopsis are much more even in height and define a distinct dorsal polygon. Your animal shows a few spikes in profile and the top shots don’t show a well defined dorsal polygon.” Thanks Cory!  For more photos and taxonomic history please see Sea Slugs of Hawaii site.