Synonyms: Tridachia crispata, Elysia clarki

Description: A large species, reaching almost 15 cm.  Highly variable in pattern and color, ranging from light green to deep blue.  Parapodia highly ruffled. Rhinophores scrolled.  Common on and around coral reefs.

Distribution: Widespread in the Gulf of Mexico, Tropical Western Atlantic and Caribbean (Marcus, 1980; Pierce et al., 2006).

Food Plants: Halimeda, Penicillus, Bryopsis

Development: Lecithotrophic.  Eggs hatch in about three weeks, depending on temperature.  Veligers settle within a few days, and commence feeding on Bryopsis plumosa.

Scientific Literature:

Cartaxana, P., Lopes, D., Martinez, B., Martins, P. and Cruz, S. (2022). Aposymbiotic Specimen of the Photosynthetic Sea Slug Elysia crispata. Diversity 14, 313.

Christa, G., Händeler, K., Kück, P., Franken, J., Karmeinski, D. and Wägele, H. (2014). Phylogenetic evidence for multiple independent origins of functional kleptoplasty in Sacoglossa (Heterobranchia, Gastropoda). Organisms Diversity & Evolution 15, 23–36.

Curtis, N. E., Pierce, S. K., Massey, S. E., Schwartz, J. A. and Maugel, T. K. (2006a). Newly metamorphosed Elysia clarki juveniles feed on and sequester chloroplasts from algal species different from those utilized by adult slugs. Marine Biology 150, 797–806.

Curtis, N. E., Massey, S. E. and Pierce, S. K. (2006b). The symbiotic chloroplasts in the sacoglossanElysia clarkiare from several algal species. Invertebrate Biology 125, 336–345.

Curtis, N. E., Schwartz, J. A. and Pierce, S. K. (2010). Ultrastructure of sequestered chloroplasts in sacoglossan gastropods with differing abilities for plastid uptake and maintenance. Invertebrate Biology 129, 297–308.

Curtis, N. E., Middlebrooks, M. L., Schwartz, J. A. and Pierce, S. K. (2015). Kleptoplastic sacoglossan species have very different capacities for plastid maintenance despite utilizing the same algal donors. Symbiosis 65, 23–31.

de Sisto, M., Crescini, R., Villalba, W., Ríos, B., Gómez, V. and Mata, Y. (2016). Sacoglosos (Opisthobranchia: Sacoglossa) del estado Nueva Esparta y Los Frailes, Venezuela. Revista Mexicana de Biodiversidad 87, 42–48.

Dionísio, G., Faleiro, F., Bilan, M., Rosa, I., Pimentel, M., Serôdio, J., Calado, R. and Rosa, R. (2017). Impact of climate change on the ontogenetic development of ‘solar-powered’ sea slugs. Marine Ecology Progress Series 578, 87–97.

Dionísio, G., Faleiro, F., Bispo, R., Lopes, A. R., Cruz, S., Paula, J. R., Repolho, T., Calado, R. and Rosa, R. (2018). Distinct Bleaching Resilience of Photosynthetic Plastid-Bearing Mollusks Under Thermal Stress and High CO(2) Conditions. Front Physiol 9, 1675–1675.

Eastman, K. E., Pendleton, A. L., Shaikh, M. A., Suttiyut, T., Ogas, R., Tomko, P., Gavelis, G., Widhalm, J. R. and Wisecaver, J. H. (2023). A reference genome for the long-term kleptoplast-retaining sea slug Elysia crispata morphotype clarki. G3: Genes, Genomes, Genetics 13, jkad234.

Gavagnin, M., Mollo, E., Cimino, G. and Ortea, J. (1996). A new γ-dihydropyrone-propionate from the caribbean sacoglossan Tridachia crispata. Tetrahedron Letters 37, 4259–4262.

Gavagnin, M., Mollo, E., Castelluccio, F., Montanaro, D., Ortea, J. and Cimino, G. (1997). A Novel Dietary Sesquiterpene from the marine SacoglossanTridachia Crispata. Natural Product Letters 10, 151–156.

Gavagnin, M., Mollo, E. and Cimino, G. (2015). Is phototridachiahydropyrone a true natural product? Revista Brasileira de Farmacognosia 25, 588–591.

Ireland, C. and Faulkner, J. (1981). The metabolites of the marine molluscs Tridachiella diomedea and Tridachia crispata. Tetrahedron 37, 233–240.

Ireland, C., Faulkner, D. J., Finer, J. S. and Clardy, J. (1979). Crispatone, a metabolite of the opisthobranch mollusc Tridachia crispata. Journal of the American Chemical Society 101, 1275–1276.

Jeffery, D. W., Perkins, M. V. and White, J. M. (2005). Synthesis of an Analogue of the Marine Polypropionate Tridachiahydropyrone. Organic Letters 7, 407–409.

Krug, P. J. (2009). Not My “Type”: Larval Dispersal Dimorphisms and Bet-Hedging in Opisthobranch Life Histories. The Biological Bulletin 216, 355–372.

Ksebati, M. B. and Schmitz, F. J. (1985). Tridachiapyrones: propionate-derived metabolites from the sacoglossan mollusk Tridachia crispata. The Journal of Organic Chemistry 50, 5637–5642.

Lopes, D., Cruz, S., Martins, P., Ferreira, S., Nunes, C., Domingues, P. and Cartaxana, P. (2022). Sea Slug Mucus Production Is Supported by Photosynthesis of Stolen Chloroplasts. Biology 11, 1207.

Lopes, D., Cunha, E., Conde, T., Moreira, A., Cruz, S., Domingues, P., Oliveira, M. and Cartaxana, P. (2024). Antimicrobial, Antioxidant and Anti-Inflammatory Activities of the Mucus of the Tropical Sea Slug Elysia crispata. Molecules 29, 4593.

Lopes, D., Cartaxana, P., Ferreira, S. S., Silva, M. I., Nunes, M., Barata, J., Nunes, C. and Cruz, S. (2025). Mucopolysaccharides secreted by the sea slug Elysia crispata incorporate carbon via kleptoplast photosynthesis. Front. Mar. Sci. 12, 1580478.

Mahadevan, P. and Middlebrooks, M. L. (2020). Bacterial diversity in the clarki ecotype of the photosynthetic sacoglossan, Elysia crispata. Microbiologyopen 9, e1098–e1098.

Middlebrooks, M. L., Pierce, S. K. and Bell, S. S. (2011). Foraging behavior under starvation conditions is altered via photosynthesis by the marine gastropod, Elysia clarki. PLoS One 6, e22162–e22162.

Middlebrooks, M. L., Bell, S. S. and Pierce, S. K. (2012). The kleptoplastic sea slug Elysia clarki prolongs photosynthesis by synthesizing chlorophyll a and b. Symbiosis 57, 127–132.

Middlebrooks, M. L., Bell, S. S., Curtis, N. E. and Pierce, S. K. (2014). Atypical plant–herbivore association of algal food and a kleptoplastic sea slug (Elysia clarki) revealed by DNA barcoding and field surveys. Marine Biology 161, 1429–1440.

Middlebrooks, M. L., Curtis, N. E. and Pierce, S. K. (2019). Algal Sources of Sequestered Chloroplasts in the Sacoglossan Sea SlugElysia crispataVary by Location and Ecotype. The Biological Bulletin 236, 88–96.

Middlebrooks, M. L., Curtis, N. E. and Pierce, S. K. (2020). The complete disappearance of a long standing sacoglossan sea slug population following Hurricane Irma, despite recovery of the local algal community. Symbiosis 80, 231–237.

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Morelli, L., Havurinne, V., Madeira, D., Martins, P., Cartaxana, P. and Cruz, S. (2024). Photoprotective mechanisms in Elysia species hosting Acetabularia chloroplasts shed light on host‐donor compatibility in photosynthetic sea slugs. Physiologia Plantarum 176, e14273.

Ortigosa, D., Lemus-Santana, E. and Simões, N. (2015). New records of ‘opisthobranchs’ (Gastropoda: Heterobranchia) from Arrecife Alacranes National Park, Yucatan, Mexico. Marine Biodiversity Records 8,.

PIERCE, S. K., CURTIS, N. E., MASSEY, S. E., BASS, A. L., KARL, S. A. and 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,.

Pierce, S. K., Curtis, N. E. and Middlebrooks, M. L. (2015). Sacoglossan sea slugs make routine use of photosynthesis by a variety of species‐specific adaptations. Invertebrate Biology 134, 103–115.

Rey, F., Vital, X. G., Cruz, S., Melo, T., Lopes, D., Calado, R., Simões, N., Mascaró, M. and Domingues, M. R. (2025). Habitat shapes the lipidome of the tropical photosynthetic sea slug Elysia crispata. Mar Life Sci Technol 7, 382–396.

Sanvicente, L., Solís-Weiss, V., Ortigosa, D., Hermoso-Salazar, M. and Lemus-Santana, E. (2012). Opisthobranch fauna from the National Park Arrecife Alacranes, southern Gulf of Mexico. Cahiers de biologie marine 53, 447–460.

Sanvicente-Añorve, L., Hermoso-Salazar, M., Ortigosa, J., Solís-Weiss, V. and Lemus-Santana, E. (2012). Opisthobranch Assemblages from a Coral Reef System: The Role of Habitat Type and Food Availability. Bulletin of Marine Science 88, 1061–1074.

Taylor, D. L. (1971). Photosynthesis of symbiotic chloroplasts in Tridachia crispata (Bërgh). Comparative Biochemistry and Physiology Part A: Physiology 38, 233–236.

THOMPSON, T. E. and JARMAN, G. M. (1989). Nutrition of Tridachia crispata (Mörch) (sacoglossa). Journal of Molluscan Studies 55, 239–244.

Trench, R. K. (1969). Chloroplasts as Functional Endosymbionts in the Mollusc Tridachia crispata (Bërgh), (Opisthobranchia, Sacoglossa). Nature 222, 1071–1072.

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Vital, X. G., Rey, F., Cartaxana, P., Cruz, S., Domingues, M. R., Calado, R. and Simões, N. (2021). Pigment and Fatty Acid Heterogeneity in the Sea Slug Elysia crispata Is Not Shaped by Habitat Depth. Animals 11, 3157.

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