This looks as though it could be an extreme variation of Thecacera picta, a species that has much bolder black bands (rather than the small spots in rows seen here) and darker orange markings on the processes, rhinophores and anterior edge of the foot. This specimen, found and photographed by Jay Lord on Halimeda on the lagoon side of Kwajalein Island, is to my knowledge the first Thecacera found in the Marshalls. If it is indeed T. picta, it is some distance outside its normal range, which includes Japan, Australia, Indonesia, the Philippines, Vanuatu, the Solomons and the Maldives. I am not aware of any Micronesian records for T. picta, which makes the Marshalls a considerable range extension, and which may account for its odd coloration; being so far away and possibly isolated from the parental color form, the Marshall Islands population may be diverging to a new species. Or it may be there already. For comparison, see the more standard color of T. picta we saw in the Philippines.
Created 25 February 2018