Elysia cf. marginata sp. 1
"Elysia cf. marginata sp. 1": Parapodia may be high or low; undulating edges form 3 wide siphonal openings. Siphons lined with orange edges but otherwise there no continuous marginal or submarginal band of color. Body covered with regularly spaced white spots and scattered black spots, dense along parapodial margin. Rhinophores with black spots on green background, white tips. No extended tail; body squared off posteriorly. Oval pericardium, posterior half white with black spots; 3-4 pairs of wide, bifurcating and anasthomosing dorsal vessels. Egg masses contain a continuous string of black extra-capsular yolk fading into grey-white streaks; planktotrophic development.
“Elysia cf. marginata sp.1", nick-named "3 siphons", is one of 4 cryptic species in the Elysia marginata complex recently documented from the Indo-Pacific using a combination of molecular, morphological, and developmental characters. Found on the green algal genus Bryopsis, the species in this complex are sometimes termed "E. ornata", which is a distinct Caribbean species, or "E. grandifolia", an Indo-Pacific taxon with no definitive characteristics.
One of 4 cryptic species in the Elysia marginata complex, all found on Bryopsis spp. Intra-specific mtDNA clades can be up to 6% divergent at the COI barcoding locus in this complex, whereas morphologically and developmentally distinct species are >8% divergent (Krug. et al., in press).
known from Guam and Moorea, French Polynesia
Members of the Elysia marginata complex and the related species E. rufescens are sources of anti-cancer compounds called kahalalides, depsipeptides derived from the algal diet of the slug; unrecognized cryptic species in this complex introduce confusion into drug discovery work by obscuring the source of new kahalalides. Clarifying taxonomic uncertainty is thus important for natural products chemistry and bioprospecting for novel chemotherapeutic agents.