Elysia crispata
(Morch, 1863)

Order: SACOGLOSSA
Superfamily: ELYSIOIDEA
Family: Elysiidae

DISTRIBUTION

Caribbean

PHOTO

Upper right: Blue colour form - off Saba Island, Caribbean. Lower right:
LOWER RIGHT: Green colour form. Note dark green colouration caused by dense populations of symbiotic chloroplasts. Bahamas. Photos: Anne Dupont.

Large elysiid, up to 50 mm long and 30 mm wide with prominent parapodia which are very folded at the edge, with both primary and secondary semipermanent folds. The parapodia on each side fuse just in front of the pericardial hump, to form a barrier between the head and the pericardium. The green colour in E. crispata is much more localised in certain areas of the body than in E. clarki. The dorsal surface between the parapodia of well-fed E. crispata is generally green, interspersed with much larger white spots which, unlike those of E. clarki, often fuse together to form extended areas devoid of green . The head of E. crispata is usually only lightly pigmented with green, sometimes with a diffuse blue band extending between the rhinophores. The sides of the body, between the base of the parapodia and the foot are also green with large white spots in well-fed individuals. The outer edge of the parapodia often has a deep blue band of variable thickness. Along the parapodial edge there can be an orange band, sometimes tending to red. It may be continuous, intermittent or lacking entirely.

The foot is relatively thick, and muscular with distinct lateral edges. It is an opaque white with no green plastids visible in it or within the ventral part of the body covered by the foot. Specimens of E. crispata typically have a narrow blue pigment band running along the edge of the foot.

E. crispata has lecithotrophic larval development [non-feeding planktonic larvae] with veliger larvae metamorphosing into juvenile slugs after about 5 days. Unfortunately the food source for juveniles is unknown. The food of the adults is still problematic but they contain symbiotic plastids from Halimeda incrassata and Penicillus capitatus, but not from any other species of Halimeda or Penicillus, although other species of both genera are present in their natural habitats. The molecular studies indicate the presence of plastids from other algal species in E. crispata as well (Pierce et al, 2006).

Both E. crispata and E. clarki retain living chloroplasts which continue to photosynthesise within the body of the sea slug, providing it with sugars for its own nutrition. See the page on Solar powered sea slugs for further information. The process of taking chloroplasts from algal cells and keeping them has been given the name kleptoplasty

Until recently this species was placed in its own genus Tridachia because of the large folded parapodia, but Gosliner (1995) has argued that this is not only unnecessary, but confuses our understanding of the phylogenetic history of the family. It is better to consider it to be a species of Elysia with a very folded parapodial edge. Elysia crispata is very variable in colour. See photos of a red-lined variety.

Note: This species has been confused with Elysia clarki for many years. See separate message [#16728] comparing the two species. Many messages previously located with the E. crispata have been transferred to E. clarki.

  • Clark, K.B. & Busacca, M. (1978) Feeding specificity and chloroplast retention in four tropical ascoglossa, with a discussion of the extent of chloroplast symbiosis and the evolution of the order. Journal of Molluscan Studies, 44: 272-282, Figs 1-3.
  • Curtis, N. E., Massey, S. E., Schwartz, J. A., Tagihof, H. & Pierce, S. K. (2004) The intracellular, functional chloroplasts in adult Elysia crispata come from several algal species, and are different from those in juvenile slugs. Integrative and Comparative Biology, 44: 686.
  • Gosliner, T.M. (1995) The Genus Thuridilla (Opisthobranchia: Elysiidae) from the Tropical Indo-Pacific, with a Revision of the Phylogeny and Systematics of the Elysiidae. Proceedings of the Californian Academy of Sciences, 49(1):1-54.
  • Jensen, K. (1980) A review of sacoglossan diets, with comparative notes on radular and buccal anatomy. Malacological Review, 13: 55-77.
  • Pierce, S.K., Curtis, N.E., Massey, S.E., Bass, A.L., Karl, S.A. & Finney, C.M. (2006) A morphological and molecular comparison between Elysia crispata and a new species of kleptoplastic sacoglossan sea slug (Gastropoda: Opisthobranchia) from the Florida Keys, USA. Molluscan Research, 26(1): 23-38
  • Taylor, D. (1970) Photosynthesis of symbiotic chloroplasts in Tridachia crispata (Bergh). Comparative Biochemistry and Physiology, 38A: 233-236.
  • Trench, R.K. (1969) Chloroplasts as functional endosymbionts in the mollusc Tridachia crispata (Bergh). Nature, 222: 1071-1072.

ARCHIVE NOTE:  An earlier edition of this Fact Sheet [6 December 1999] is available on request.

Authorship details
Rudman, W.B., 2006 (May 30) Elysia crispata (Morch, 1863). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/elyscris

Related messages

  1. Lettuce slug behaviour
    From: Bob Bailey, March 26, 2010
  2. Two Elysia crispata from Saba, Windward Islands
    From: Eric Kaye, March 26, 2010
  3. Colour variations of Elysia crispata from Guadeloupe [2]
    From: Hugues Flodrops, November 21, 2007
  4. Colour variations of Elysia crispata from Guadeloupe [1]
    From: Hugues Flodrops, November 21, 2007
  5. Elysia with a ripped body
    From: Patrick, October 4, 2007
  6. Location of Elysia crispata - and other slugs?
    From: Paul Jones, September 22, 2007
  7. Elysia crispata? from Cuba
    From: Simon Crawford, March 23, 2007
  8. Re: Update on Elysia crispata feeding
    From: Andrew Rodenbeck, August 30, 2006
  9. Damaged Elysia crispata
    From: D. Rose, August 28, 2006
  10. Re: Update on Elysia crispata feeding
    From: Colin Finney, May 6, 2005
  11. Re: Update on Elysia crispata feeding
    From: Skip Pierce, May 4, 2005
  12. Re: Update on Elysia crispata feeding
    From: Kathe R. Jensen, May 2, 2005
  13. Re: Update on Elysia crispata feeding
    From: Lindsey Holm, May 2, 2005
  14. Elysia crispata - Here's a puzzle
    From: Skip Pierce, January 4, 2005
  15. Update on Elysia crispata feeding
    From: Skip Pierce, August 6, 2004
  16. Re: Elysia crispata feeding
    From: Pszemol, July 16, 2004
  17. Re: Elysia feeding
    From: Skip Pierce, March 1, 2004
  18. Re: Elysia feeding
    From: Kathe R. Jensen, February 27, 2004
  19. Elysia feeding
    From: Skip Pierce, February 26, 2004
  20. Elysia crispata - breeding in aquarium
    From: Paul Baldassano, January 9, 2004
  21. Elysia crispata from Jamaica
    From: Ross W. Gundersen, October 10, 2003
  22. Elysia crispata from Colombia
    From: Ana Karina Yepes, October 1, 2003
  23. Elysia crispata from Bonaire
    From: Robert Fishman, September 11, 2003
  24. Light color form of Elysia crispata
    From: Linda Ianniello, July 21, 2003
  25. Chloroplasts in Elysia crispata
    From: Skip Pierce, June 30, 2003
  26. More on Elysia crispata - feeding, DNA etc
    From: Skip Pierce, May 8, 2003
  27. Re: Elysia crispata and algal genes
    From: Kathe R. Jensen, May 5, 2003
  28. Elysia crispata research
    From: Dirk Trauner , March 11, 2003
  29. Elysia crispata toxicity..
    From: Ken Woden, September 17, 2002
  30. Re: Elysia crispata question...
    From: Matt Galvin, December 18, 2001
  31. Elysia crispata question...
    From: Rich Hunziker , December 12, 2001
  32. Re: Advice of keeping Elysia crispata in captivity
    From: Kathe R. Jensen, October 9, 2001
  33. Re: Elysia crispata
    From: Anne DuPont, October 9, 2001
  34. Chloroplasts in the 'lettuce leaf nudibranch'
    From: Caroline Nelson, October 8, 2001
  35. Re: Advice of keeping Elysia in captivity
    From: Claude Poole, September 24, 2001
  36. I need some Bryopsis
    From: Kathleen Archer , September 21, 2001
  37. Re: Advice of keeping Elysia in captivity
    From: Kathe R. Jensen, September 17, 2001
  38. Advice of keeping Elysia in captivity
    From: Kathleen Archer , September 15, 2001
  39. Elysia crispata from Colombia
    From: Alexander Taborda Marin, June 16, 2001
  40. Keeping Elysia crispata in aquaria
    From: Alan Pittman, February 26, 2001
  41. Elysia crispata in aquaria
    From: Ryan, January 29, 2001
  42. What is a Lettuce Nudibranch
    From: Mike Dean, October 30, 2000
  43. Elysia crispata v Tridachia crispata
    From: Kathe R. Jensen, October 17, 2000
  44. Re: Elysia crispata - egg coil
    From: Kathe R. Jensen, October 15, 2000
  45. Elysia crispata - egg coil
    From: John Batson, October 6, 2000
  46. Re: Lettuce Slug
    From: Jonathan Laxton, August 3, 2000
  47. What is a lettuce slug? help please......!
    From: Jonathan LAxton, July 28, 2000
  48. Elysia crispata & photosynthesis
    From: Dave Behrens, December 10, 1999
  49. Tridachia v Elysia crispata
    From: David W. Behrens, December 7, 1999
  50. Photos of the solar-powered 'Ruffled Sea Slug'
    From: Anne DuPont, December 7, 1999
  51. Red-lined form of Tridachia crispata
    From: Anne Dupont, December 7, 1999

Show factsheet and all related messages