Elysia rufescens is a species of sea slug, a marine gastropod mollusc in the family Plakobranchidae. This sea slug resembles a nudibranch but is not classified in that order of gastropods, instead belonging to a closely related clade, Sacoglossa, the "sap-sucking" sea slugs. This species was first described by Pease from Tahiti in 1871.

Elysia rufescens
Original drawing used by Pease when he described the species in 1871.
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Heterobranchia
Family: Plakobranchidae
Genus: Elysia
Species:
E. rufescens
Binomial name
Elysia rufescens
(Pease, 1871) [1]

Description edit

Elysia rufescens is olive green with large white spots, often in a reticulated pattern, and grows to about 6 centimetres (2.4 in). The parapodia are somewhat convoluted and have dark blue edges and a submarginal orange line. The rhinophores are rolled and have blunt, greyish ends.[2][3]

Distribution edit

Elysia rufescens is found in the Pacific Ocean. Its range includes the coastlines of South Africa, Réunion, Thailand, Myanmar, the Philippines, Japan, Guam, Samoa, Tahiti, Hawaii and Australia.[3]

Biology edit

Elysia rufescens feeds on green filamentous algae such as Bryopsis pennata, which it rasps with each of a series of rachidian teeth.[3] E. rufescens grazes on Bryopsis sp., an alga that defends itself from predators by using peptide toxins with fatty acids, called kahalalides.[4] A bacterial obligate symbiont produces many defensive molecules, including kahalalides, in order to protect the alga. This bacteria is able to use substrates derived from the host in order to synthesize the toxins.[4] The Hawaiian Sea Slug grazes on the alga in order to accumulate kahalalide. This uptake of the toxin, which the slug is immune to, allows it to also become toxic to predators. This shared ability, both originating from the bacteria, provide protection within the marine ecosystems.[4]

References edit

  1. ^ Tran, Bastien (2010). "Elysia rufescens (Pease, 1871)". WoRMS. World Register of Marine Species. Retrieved 2012-01-27.
  2. ^ Elysia rufescens (Pease, 1871) The Sea Slug Forum. Retrieved 2012-01-27.
  3. ^ a b c Elysia rufescens The Slug Site. Retrieved 2012-01-27.
  4. ^ a b c Zan J, Li Z, Tianero MD, Davis J, Hill RT, Donia MS (June 2019). "A microbial factory for defensive kahalalides in a tripartite marine symbiosis". Science. 364 (6445): eaaw6732. doi:10.1126/science.aaw6732. PMID 31196985. S2CID 189818260.