Tropical and warmwater Atlantic. Mots records are from the western Atlantic [Caribbean to Brazil] but it has also been sometimes recorded from the Mediterranean.
Locality: St.. John's, intertidal, Antigua, Caribbean Ocean, 12 April 2009, Shallow coral shoal. Length: 10 mm. Photographer: D.Y. Zhang.
The animal is a translucent yellowish colour with the dark green branching of the parapodial digestive gland showing though. There are some white papillae on the outside of the parapodia and a whitish border to the parapodia. Along the edge of the parapodial are raised opaque white rounded papillae. There are also a pair of white spots on the skin above the eyes, and also in the same region the orange buccal bulb can be seen through the body wall.
Although this species seems to be widespread in the western Atlantic, the first report of it after Verrill's description from Bermuda in 1901 was Thompson's 1977 record from Jamaica. Thompson & Jaklin (1988) also recorded it from the eastern Mediterranean, and since then there have been occasional records from mediterraean waters. It has many similarities to the western Pacific species Elysia obtusa Baba, 1938
Marcus, E. (1980). Review of western Atlantic Elysiidae (Opisthobranchia Ascoglossa) with a description of a new Elysia species. Bulletin of Marine Science, 30(1): 54-79.
Thompson, T. E. (1977). Jamaican opisthobranch molluscs I. Journal of Molluscan Studies, 43(2): 93-139,pls.1-3.
Thompson, T. E. and A. Jaklin (1988). Eastern Mediterranean opisthobranchia: Elysiidae (Sacoglossa = Ascoglossa). Journal of Molluscan Studies, 54: 59-69.
Verrill, A. E. (1901). Additions to the fauna of the Bermudas. Transactions of the Connecticut Academy of Science, 11: 15-62.
Rudman, W.B., 2009 (June 2) Elysia flava Verrill, 1901. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/elysflav