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Published: 2022-12-20
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Anatomical redescription of Aplysia (Aplysia) nigra and Aplysia (Varria) inca (Mollusca: Heterobranchia) with comments on Aplysia from Peru

Laboratorio de Biología y Sistemática de Invertebrados Marinos (LaBSIM), Facultad de Ciencias Biológicas, Universidad Nacional Mayor de San Marcos, Lima, Perú.
Laboratorio de Biología y Sistemática de Invertebrados Marinos (LaBSIM), Facultad de Ciencias Biológicas, Universidad Nacional Mayor de San Marcos, Lima, Perú.
Mollusca Anaspidea Eastern Pacific redescription anatomy


During the past century eight species of sea hares of the genus Aplysia were recorded from Peru. However, there is disagreement about how many of these species are valid and their taxonomy needs to be critically evaluated. Based on detailed morphological examinations, this study presents a redescription of Aplysia nigra d’Orbigny, 1837 and Aplysia inca d’Orbigny, 1837, the most common species of Aplysia along the Peruvian coast. They showed consistent morphological differences, mainly in the foot, parapodia development, opaline gland, jaws, radular teeth and penial morphology. Anatomical data for both species are provided for the first time, as well as a comparison with other species of Aplysia reported for the Eastern Pacific. The records of Aplysia keraudreni Rang, 1828, Aplysia dactylomela Rang, 1828 and Aplysia juliana Quoy & Gaimard, 1832 for Peruvian waters are likely erroneous and need to be verified based on collected specimens.



  1. Alamo, V. & Valdivieso, V. (1997) Lista Sistemática de Moluscos Marinos del Perú (Segunda Edición, revisada y actualizada). Publicación Especial. Instituto del Mar del Perú, Callao, 183 pp.
    Alexander, J. & Valdés, A. (2013) The ring doesn’t mean a thing: molecular data suggest a new taxonomy for two Pacific species of sea hares (Mollusca: Opisthobranchia, Aplysiidae). Pacific Science, 67 (2), 283–294.
    Allan, J. (1932) Sea Hares. The Australian Museum Magazine, 4 (12), 419–425.
    Allan, J. (1941) Australian sea hares and tailed sea-slugs. The Victorian Naturalist, 57, 178–182.
    Araya, J.F. (2015) Current status of the non-indigenous molluscs in Chile, with the first record of Otala punctata (Müller, 1774) (Gastropoda: Helicidae) in the country and new records for Cornu aspersum (Müller, 1774) and Deroceras laeve (Müller, 1774). Journal of Natural History, 49 (29–30), 1731–1761.
    Araya, J.F. & Valdés, A. (2016) Shallow water heterobranch sea slugs (Gastropoda: Heterobranchia) from the Región de Atacama, northern Chile. PeerJ, 4, e1963.
    Bartsch, P. & Rehder, H.A. (1939) Mollusks collected on the presidential cruise of 1938. Smithsonian Miscellaneous Collections, 98 (10), 1–18, 5 pls.
    Barraza, J.E. (2014) Invertebrados marinos de El Salvador. Ministerio de Medio Ambiente y Recursos Naturales (MARN), El Salvador, 96 pp.
    Bazzicalupo, E., Crocetta, F., Gosliner, T.M., Berteaux-Lecellier, V., Camacho-García, Y.E., Chandran, B.K.S. & Valdés, A. (2020) Molecular and morphological systematics of Bursatella leachii de Blainville, 1817 and Stylocheilus striatus Quoy & Gaimard, 1832 reveal cryptic diversity in pantropically distributed taxa (Mollusca: Gastropoda: Heterobranchia). Invertebrate Systematics, 34 (5), 535–568.
    Bebbington, A. (1977) Aplysiid species from Eastern Australia with notes on the Pacific Ocean Aplysiomorpha (Gastropoda, Opisthobranchia). Transactions of the Zoological Society of London, 34 (1), 87–147.
    Bebbington, A. & Thompson, T.E. (1968) Note sur les Opisthobranchs du Bassin d’Arcachon. Actes de la Société linnéenne de Bordeaux, 105 (5), 1–35.
    Beeman, R.D. (1960) A new tectibranch, Aplysia reticulopoda, from the southern California coast. Bulletin of the Southern California Academy of Sciences, 59 (3), 144–152.
    Beeman, R.D. (1968) The order Anaspidea. The Veliger, 3 (Supplement), Part. 2, 87–102.
    Beeman, R.D. (1970) The anatomy and functional morphology of the reproductive system in the opisthobranch mollusk Phyllaplysia taylori Dall, 1900. The Veliger, 13 (1), 1–31.
    Behrens, D.W. & Hermosillo, A. (2005) Eastern Pacific Nudibranchs. A guide to the Opisthobranchs from Alaska to Central America. Sea Challengers, Monterey, California, 137 pp.
    Bertsch, H. (2010) Biogeography of Northeast Pacific Opisthobranchs: Comparative Faunal Province Studies Between Point Conception, California, USA, and Punta Aguja, Piura, Perú. In: Rangel, L.J., Gamboa, J., Arriaga, S.L. & Contreras, W.M. (Eds.), Perspectivas en Malacología Mexicana. División Académica de Ciencias, Universidad Juárez Autónoma de Tabasco, Tabasco, pp. 219–259.
    Camacho-García, Y., Gosliner, T.M. & Valdés, A. (2005) Guía de Campo de las Babosas Marinas del Pacífico Este Tropical. California Academy of Sciences, San Francisco, California, 129 pp.
    Carefoot, T.H. (1987) Aplysia: its biology and ecology. Oceanography and Marine Biology: An Annual Review, 25, 167–284.
    Castilla, J.C., Uribe, M., Bahamonde, N., Bahamonde, N., Clarke, M., Desqueyroux-Faúndez, R., Kong, I., Moyano, H., Rozbaczylo, N., Santelices, B., Valdovinos, C. & Zavala, P. (2005) Down under the southeastern Pacific: marine non-indigenous species in Chile. Biological Invasions, 7, 213–232.
    Chávez-Viteri, Y.E., Brown, F.D. & Pérez, O.D. (2017) Deviating from the norm: peculiarities of Aplysia cf. californica early cleavage compared to traditional spiralian models. Journal of Experimental Zoology (Part B: Molecular and Developmental Evolution), 328B, 72–87.
    Cooper, J.G. (1863) On new or rare Mollusca inhabiting the coast of California. No II. Proceedings of the California Academy of Sciences, 3, 56–60.
    Cruz, M., Hill, D. & Cortez, P. (2007) Biología y Distribución de la Familia Aplysiidae (babosas de mar), en la zona intermareal del Ecuador, desde el 2003 al 2005. Acta Oceanográfica del Pacífico, 14 (1), 155–161.
    Cunha, C.M. & Simone, L.R.L. (2018) Morphological re-description of Aplysia depilans (Gastropoda: Anaspidea): new insights into the anatomy of the anaspideans. Journal of the Marine Biological Association of the United Kingdom, 99 (3), 595–610.
    Eales, N.B. (1921) Aplysia. Liverpool Marine Biodiversity Committee Memoirs, 24, 1–84, 7 pls.
    Eales, N.B. (1957) Revision of the species of Aplysia of the Museum National d’Histoire Naturelle (Malacologie), Paris. Bulletin du Museum National d’Histoire Naturelle, 2 (29), 246–255.
    Eales, N.B. (1960) Revision of the world species of Aplysia (Gastropoda, Opisthobranchia). Bulletin of the British Museum Zoology, 5 (10), 267–404.
    Engel, H. & Hummelinck, P.W. (1936) Über westindische Aplysiidae und Verwandten anderer Gebiete. Capita Zoologica, 8 (1), 1–76.
    Engel, H. & Eales, N.B. (1957) The species of Aplysia belonging to the subgenus Tullia Pruvot-Fol, 1933: On a generic character in statu nascendi. Beaufortia, 6 (69), 83–114.
    Finet, Y., Chiriboga, A., Ruiz, D., Banks, S. & Tirado, N. (2011) CDF Checklist of Galapagos marine mollusks. In: Bungartz, F., Herrera, H., Jaramillo, P., Tirado, N., Jímenez-Uzcategui, G., Ruiz, D., Guézou, A. & Ziemmeck, F. (Eds.), Charles Darwin Foundation Galapagos species checklist. Charles Darwin Foundation, Puerto Ayora, pp. 1–164.
    Golestani, H., Crocetta, F., Padula, V., Camacho-García, Y., Langeneck, J., Poursanidis, D., Pola, M., Yokeş, M.B., Cervera, J.L., Jung, D., Gosliner, T.M., Araya, J.F., Hooker, Y., Schrödl, M. & Valdés, A. (2019) The little Aplysia coming of age: from one species to a complex of species complexes in Aplysia parvula (Mollusca: Gastropoda: Heterobranchia). Zoological Journal of the Linnean Society, 187 (2), 279–330.
    Hermosillo, A. & Camacho-García, Y.E. (2006) A note on the Opisthobranchs of Parque Nacional de Coiba, Panamá (Tropical Eastern Pacific). The Festivus, 38 (9), 95–98.
    Hermosillo, A., Behrens, D.W. & Ríos-Jara, E. (2006) Opistobranquios de México. Guía de babosas marinas del Pacífico, Golfo de California y las islas oceánicas. CONABIO, México City, 144 pp.
    Hutton, F.W. (1875) Description of two new Species of Aplysia. Transactions and Proceedings of the New Zealand Institute, 7, 279, pl. 21.
    Johnson, P.M. & Willows, A.O.D. (1999) Defense in sea hares (Gastropoda, Opisthobranchia, Anaspidea): Multiple layers of protection from egg to adult. Marine and Freshwater Behaviour and Physiology, 32 (2–3), 147–180.
    Kandel, E.R. (1979) Behavioral biology of Aplysia: A contribution to the comparative study of opisthobranch molluscs. W.H. Freeman & Company, San Francisco, 463 pp.
    Kandel, E.R., Koester, J.D., Mack, S.H. & Siegelbaum, S.A. (2021) Principles of neural science Sixth Edition. McGraw-Hill, New York, New York, 1414 pp.
    Kay, E.A. (1964) The Aplysiidae of the Hawaiian Islands. Proceedings of the Malacological Society of London, 36 (3), 173–190.
    Keen, A.M. (1966) West American mollusk types at the British Museum (Natural History) III. Alcide d’Orbigny’s South American Collection. The Veliger, 9 (1), 1–7.
    Keen, A.M. (1971) Sea Shells of Tropical West America: Marine Mollusks from Baja California to Peru. 2nd Edition. Stanford University Press, Stanford, California, 1064 pp., 22 pls.
    Kirk, T.W. (1882) Description of New Shells. Transactions and Proceedings of the New Zealand Institute, 14, 282–283.
    Klussmann-Kolb, A. (2004) Phylogeny of the Aplysiidae (Gastropoda: Ophisthobranchia) with new aspects of the evolution of sea hares. Zoologica Scripta, 35 (5), 439–462.
    Lima, P.O.V. (2016) Análise filogenética de Cryptobranchia (Mollusca: Nudibranquia) com base em anatomia comparada. PhD thesis, Instituto de Biociências, Universidade de São Paulo, São Paulo, 326 pp.
    Linnaeus, C. (1767) s.n. In: Systema naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tom. 1. Par. 2. 12th Edition. Laurentii Salvii, Holmiae [Stockholm], pp. 533–1327.
    MacFarland, F.M. (1909) The Opisthobranchiate Mollusca of the Branner-Agassiz expedition to Brazil. Leland Stanford Junior University Publications. Stanford University, California, University Series 2. Stanford University, California, 104 pp. 19 pls.
    MacFarland, F.M. (1966) Studies of Opisthobranchiate Mollusks of the Pacific Coast of North America. Memoirs of the California Academy of Sciences, 6, 546 pp. 72 pls.
    Marcus, E. (1956) Notes on Opisthobranchia. Boletim do Instituto Oceanográfico, 7 (1–2), 31–78.
    Marcus, E. & Marcus, E. (1957) Notes on Aplysia. Boletim do Instituto Oceanográfico, 8 (1–2), 3–21.
    Marcus, E. & Marcus, E. (1967) American Opisthobranch Mollusks. Studies in Tropical Oceanography. Institute of Marine Science, University of Miami, Florida, 6, 256 pp.
    Mazzarelli, G.F. & Zuccardi, R. (1889) Su di alcune Aplysidae dell’Oceano Pacifico, appartenenti alla colllezione Chierchia. Bollettino della Societá di naturalisti in Napoli, 3, 47–54.
    Mazzarelli, G.F. & Zuccardi, R. (1890) Sulle Aplysiidae raccolte dal tenente di Vascello Gaetano Chierchia nel Viaggio della Vettor-Pisani (1882-1885). Memorie della Società Italiana delle Scienze, 8 (2), 1–21.
    Medina, M., Collins, T.M. & Walsh, P.J. (2001) mtDNA Ribosomal Gene Phylogeny of Sea Hares in the Genus Aplysia (Gastropoda, Opisthobranchia, Anaspidea): Implications for Comparative Neurobiology. Systematics Biology, 50 (5), 676–688.
    Medina, M., Collins, T.M. & Walsh, P.J. (2005) Phylogeny of Sea Hares in the Aplysia Clade Based on Mitochondrial DNA Sequence Data. Bulletin of Marine Science, 76 (3), 691–698.
    MolluscaBase eds. (2021) MolluscaBase. Aplysia Linnaeus, 1767. Available from: (accessed 15 April 2022)
    Morley, M.S. & Hayward, B.W. (2015) Intertidal records of ‘sea slugs’ (nudibranchs and allied opisthobranch gastropods) from northern North Island, New Zealand. Records of the Auckland Museum, 50, 51–93.
    Nakamura, K. (2006) New Records of Opisthobranch Mollusks from the Guayaquil Marine Ecoregion: Northern Peru. The Festivus, 38 (7), 75–83.
    Nakamura, K. (2007) Especies bentónicas de Opisthobranchia (Mollusca: Gastropoda) presents en el litoral del norte peruano. Revista Peruana de Biología, 13 (3), 255–257.
    Nimbs, M.J. (2020) The taxonomy and systematics of the Australian Aplysiidae (Mollusca: Gastropoda). PhD thesis, Southern Cross University, New South Wales, 355 pp.
    Nimbs, M.J., Willan, R.C. & Smith, S.D.A. (2017a) A Historical Summary of the Distribution and Diet of Australian Sea Hares (Gastropoda: Heterobranchia: Aplysiidae). Zoological Studies, 56 (35), 1–14.
    Nimbs, M.J., Willan, R.C. & Smith, S.D.A. (2017b) Is Port Stephens, eastern Australia, a global hotspot for biodiversity of Aplysiidae (Gastropoda: Heterobranchia)? Molluscan Research, 37 (1), 45–65.
    d’Orbigny, A. (1837) Voyage dans l’Amérique méridionale (le Brésil, la république orientale de l’Uruguay, la république Argentine, la Patagonie, la république du Chile, la république de Bolivia, la république du Pérou), exécuté pendant les annés 1826, 1827, 1828, 1829, 1830, 1831, 1832, et 1833. Tome 5. Partie 3. Mollusques. P. Bertrand, Paris, 758 pp.
    Paredes C., Tarazona, J., Canahuire, E., Romero, L. & Cornejo, O. (1988) Invertebrados Macro-Bentónicos del Área de Pisco, Perú. In: Salzwedel, H. & Landa, A. (Eds.), Recursos y dinámica del ecosistema del afloramiento peruano. Boletin Instituto del Mar del Perú, Callao, Peru, Volumen Extraordinario, pp. 121–132.
    Paredes C., Cardoso, F. & Tarazona, J. (1999a) Invertebrados del intermareal rocoso del departamento de Lima, Perú: Una lista comentada de especies. Revista Peruana de Biología, 6 (2), 143–151.
    Paredes C., Huamán, P., Cardoso, F., Vivar, R. & Vera, V. (1999b) Estado actual del conocimiento de los Moluscos Acuáticos en el Perú. Revista Peruana de Biología, 6 (1), 5–47.
    Pilsbry, H.A. (1895) Manual of Conchology. Vol. 16. Philinidae, Gastropteridae, Aglajidae, Aplysiidae, Oxynoeidae, Runcinidae, Umbraculidae, Pleurobranchidae. Academy of Natural Sciences, Philadelphia, Pennsylvania, 262 pp., 74 pls.
    PNUD (2014) Moluscos Invasores de Chile: Documento del Taller Moluscos Exóticos Invasores en Chile: Efectos en la Biodiversidad. Programa de las Naciones Unidas para el Desarrollo, Santiago de Chile, 63 pp.
    Quoy, J.R.C. & Gaimard, J.P. (1832) Voyage de découvertes de l'"Astrolabe" exécuté par ordre du Roi, pendant les années 1826-1829, sous le commandement de M. J. Dumont d'Urville. Zoologie 2. Tastu, Paris, 321 pp.
    Ramírez, R., Paredes, C. & Arenas, J. (2003) Moluscos del Perú. Revista de Biología Tropical, 51 (Supplement 3), 225–284.
    Ramírez, P., De La Cruz, J., Castro, J. & Barriga, E. (2015) Biodiversidad Marina en la Isla Lobos de Tierra, Perú. Informe Instituto del Mar del Perú, 42 (1), 7–34.
    Rang, S. (1828) Histoire naturelle des Aplysiens. Firmin Didot, Paris, 83 pp., 24 pls.
    Rudman, W.B. (2003) Comment on Aplysia juliana from New Zealand by Paul Furneaux. Sea Slug Forum, Australian Museum, Sydney. Available from: (accessed 15 April 2022)
    Rudman, W.B. (2006) Aplysia vaccaria Winkler, 1955. Sea Slug Forum, Australian Museum, Sydney. Available from: (accessed 15 April 2022)
    Saad, L.O., Cunha, C.M., Colpo, K.D. & Valdés, A. (2014) It’s not what it looks like: molecular data fails to substantiate morphological differences in two sea hares (Mollusca, Heterobranchia, Aplysiidae) from southern Brazil. Helgoland Marine Research, 68 (4), 523–530.
    Schrödl M. & Hooker, Y. (2014) Sea slugs of Peru: Peruvian-Chilean faunal elements. Spixiana, 37 (1), 45–59.
    Simone, L.R.L. (2011) Phylogeny of the Caenogastropoda (Mollusca), based on comparative morphology. Arquivos de Zoologia, 42 (4), 161–323.
    Sowerby II, G.B. (1869) Monograph of the genus Aplysia. In: Reeve, L.A. (Ed.), Conchologia iconica: or illustrations of the shells of molluscous animals. Vol. 17. L. Reeve & Co, London, pp. 202–218, 10 pls.
    Suter, H. (1913) Manual of the New Zealand Mollusca. Mackay, Wellington, 1120 pp. 72 pls. [1915]
    Thompson, T.E. & Bebbington, A. (1969) Structure and Function of the Reproductive Organs of three species of Aplysia (Gastropoda: Opisthobranchia). Malacologia, 7 (2–3), 347–380.
    Uribe, R.A, Nakamura, K., Indacochea, A., Pacheco, A.S., Hooker, Y. & Schrödl, M. (2013a) A review on the diversity and distribution of opisthobranch gastropods from Peru, with addition of three new records. Spixiana, 36 (1), 43–60.
    Uribe, R.A., Rubio, J., Carbajal, P. & Berrú, P. (2013b) Invertebrados Marinos Bentónicos del Litoral de la Región Ancash, Perú. Boletin Instituto del Mar del Perú, 28 (1–2), 136–293.
    Valdés, A. (2019) Northeast Pacific benthic shelled sea slugs. Zoosymposia, 13, 242–304.
    Valdés, A. & Héros, V. (1998) The types of Recent and certain fossil opisthobranch molluscs in the Muséum national d’Histoire naturelle, Paris. Zoosystema, 20 (4), 695–742.
    Willan, R.C. (1979) The Ecology of Two New Zealand Opisthobranch Molluscs. PhD thesis, University of Auckland, Auckland, 278 pp.
    Willan, R.C. & Morton, J. (1984) Cape Rodney to Okakari Point Marine Reserve. Marine Molluscs. Part 2. Opisthobranchia. Leigh Marine Laboratory, Leigh, 106 pp.
    Winkler, L.R. (1955) A new species of Aplysia on the southern California coast. Bulletin of the Southern California Academy of Sciences, 54 (1), 5–7.
    Winkler, L.R. (1957) The Biology of California Sea Hares of the Genus Aplysia. PhD thesis, University of Southern California, Los Angeles, California, 201 pp.