Skip to main content Skip to main navigation menu Skip to site footer
Type: Article
Published: 2019-11-18
Page range: 30–58
Abstract views: 138
PDF downloaded: 4

New genus, new species and new records of marine acotylean flatworms (Platyhelminthes: Polycladida: Acotylea) from Oaxaca, southern Mexican Pacific

Laboratorio de Sistemática de Invertebrados Marinos (LABSIM), Universidad del Mar, campus Puerto Ángel, Ciudad Universitaria, Apdo. Postal 47, Puerto Ángel, Oaxaca, 70902, México.
Rosenstein 1, Staatliches Museum für Naturkunde Stuttgart, Germany.
Laboratorio de Sistemática de Invertebrados Marinos (LABSIM), Universidad del Mar, campus Puerto Ángel, Ciudad Universitaria, Apdo. Postal 47, Puerto Ángel, Oaxaca, 70902, México.
Platyhelminthes Bisacculosuteri gen. nov. Bivesiculoplana Euplanoida histological approach Paraplanocera


The acotylean polyclads are characterized by the absence of a ventral sucker located posteriorly to the female gonopore. These flatworms are mostly marine, benthic or pelagic, except by two species, one freshwater Limnostylochus borneensis and other semi-terrestrial Myoramyxa pardalota. Oaxaca is a state located in the southern Mexican Pacific, where only three acotyleans species have been formally recorded until now. After sampling littoral to sublittoral zones, a total of 34 specimens were collected and fixed in frozen formalin. Some specimens were stained with Mayer´s carmalum and hematoxylin and cleared in methyl salicylate for whole mounts; the portion containing the reproductive structures of other specimens were dissected and histologically processed in sagittal and frontal sections. Four species were identified as belonging to four genera and three families. The new genus Bisacculosuteri gen. nov. is established, close to the genus Itannia, but lacking double ventral suckers placed on both sides of the female gonopore. Two species are new to science: Bisacculosuteri marcelae sp. nov., characterized by a highly branched central pharynx, prominent seminal vesicle, a penis papilla with stylet, paired strongly muscularized uterine sac and uterine vesicles; and Paraplanocera oligoglenoides sp. nov., with translucent body, light brown pigmentation and black dots distributed in the pharyngeal and reproductive regions, and an oval cirrus sac with intramuscular surrounding hollow spaces and armored with spines and conspicuous teeth. The third species is Euplanoida cf. pacificola that could not be determined as the nominal species, due to ambiguity in its description. The fourth species, Bivesiculoplana lamothei, was previously described from the region and now is recorded in new localities and hosts from Oaxaca.



  1. Aguado, M.T., Noreña C., Alcaraz, L., Marquina, D., Brusa. F., Damborenea, C., Almon, B., Bleidorn, C. & Grande, C. (2017) Phylogeny of Polycladida (Platyhelminthes) based on mtDNA data. Organisms Diversity & Evolution, 17 (4), 767–778.

    Bahia, J., Padula, V. & Schrödl M. (2017) Polycladida phylogeny and evolution: integrating evidence from 28S rDNA and morphology. Organisms Diversity & Evolution, 17 (3), 653–678.

    Bastida-Zavala, J.R., García-Madrigal, M.S., Rosas-Alquicira, E.F., López-Pérez, R.A., Benítez-Villalobos, F., Meraz-Hernando, J.F., Torres-Huerta, A.M., Montoya-Márquez, A. & Barrientos-Luján, N.A. (2013) Marine and coastal biodiversity of Oaxaca, México. Check List, 9 (2), 329–390.

    Bock, S. (1913) Studien über Polycladen. Zoologiska Bidrag Uppsala, 2, 31–344. []

    Bolaños, D.M., Quiroga, S.Y. & Litvaitis, M.K. (2007) Five new species of cotyleans flatworms (Platyhelminthes: Polycladida) from the wider Caribbean. Zootaxa, 1650 (1), 1–23.

    Brusa, F. & Damborenea, C. (2013) A new polyclad species associated with Bankia martensi (Bivalvia) from the South Pacific coast of Chile, and its taxonomic position within Euplanidae (Platyhelminthes, Ilyplanoidea). Journal of the Marine Biological Association of the United Kingdom, 94 (1), 167–176.

    Brusca, R.C. (1980) Common intertidal invertebrates of the Gulf of California. 2a ed., University of Arizona Press, Tucson, 513 pp. []

    Cabezas-Rodríguez, M.P., Santos, A.M., Branco, M. & Guerra-García, J.M. (2016) Biodiversidad y especiación críptica en los caprélidos (Crustacea: Amphipoda): ¿Cuánto falta por descubrir? Chronica nature, 6, 24–32. []

    Cannon, L.R.G. (1986) Turbellaria of the world. A guide to families & genera. Queensland Museum, Brisbane, 136 pp.

    Carpenter, P.P. (1856) Description of new species of shells collected by Mr. T. Bridges in the Bay of Panama and its vicinity, in the collection of Hugh Cuming, Esq. Proceedings of the Zoological Society of London, 1856, 159–166.

    Carpenter, P.P. (1857) Catalogue of the collection of Mazatlan shells in the British Museum collected by Frederick Reigen. Printed by order of the Trustees, London, xvi + 552 pp.

    Du Bois-Reymond Marcus, E. (1957) On Turbellaria. On terrestrial triclads, Convoluta, Hofstenia, Notoplana chierchiae, Itania ornata, Cestoplana. Anais da Academia Brasileira de Ciências, 29, 153–191.

    Ehlers, U. (1985) Das phylogenetische System der Plathelminthes. Gustav Fischer Verlag, Stuttgart, 317 pp.

    Ehrenberg, C.G. (1831) Phytozoa, Turbellaria africana et asiatica. In: Hemprich, P.C. & Ehrenberg, C.G. (Eds.), “Symbolae physicae.” Animalia evertebrata exclusis insectis recensuit Dr. C.G Ehrenberg, Series prima cum tabularum decade prima, Berolini, Fol. Phytozoa Turbellaria Folia a–d, T4–5.

    Faubel, A. (1983) The Polycladida, Turbellaria proposal and establishment of a new system part. I. The Acotylea. Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 8, 17–121.

    Faubel, A. (1984a) On the geographical occurrence of pelagic polyclad turbellarians. Cahiers de Biologie Marine, 25, 153–168. Available from: (Accessed 15 Nov. 2019)

    Faubel, A. (1984b) The Polycladida, Turbellaria proposal and establishment of a new system part. II. The Cotylea. Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 81, 189–259.

    Faubel, A., Sluys, R. & Reid, D.G. (2007) A new genus and species of polyclad flatworm found in the mantle cavities of gastropod mollusks in the high-intertidal zone of the Pacific coast of Central America. Journal of the Marine Biological Association of the United Kingdom, 87, 429–434.

    Girard, C.F. (1893) Recherches sur les planariés et les némertines de L’Amérique du Nord. Annales des Sciences Naturelles, Series 7, Zoology, 15, 145–310.

    González, N.E. & Salazar-Vallejo, S.I. (1996) Simbiosis entre Colisella spp. (Gastropoda) y Zygantroplana ups (Platyhelminthes: Turbellaria) en el Golfo de California, México. Revista de Biología Tropical, 44 (1), 97–105. Available from: (Accessed 15 Nov. 2019)

    Hyman, L.H. (1944) A new Hawaiian polyclad flatworm associated with Teredo. Occasional Papers of the Bernice P. Bishop Museum, 18 (4), 73–75.

    Hyman, L.H. (1951) The Invertebrates. Vol II. Platyhelminthes and Rhynchooela; the Acoelomate Bilateria. MCGraw-Hill, Book Company, Inc., New York, 572 pp.

    Hyman, L.H. (1953a) The polyclad flatworms of the Pacific coast of North America. Bulletin of the American Museum of Natural History, 100 (2), 265–392.


    Hyman, L.H. (1953b) Some polyclad flatworms from the Galapagos Islands. Allan Hancock Pacific Expeditions, 15 (2), 183–210. Available from: (Accessed 15 Nov. 2019)

    Hyman, L.H. (1954) Some polyclad flatworms from the Hawaiian Islands. Pacific Science, 8, 331–336. Available from: (Accessed 15 Nov. 2019)

    Hyman, L.H. (1955) Some polyclad flatworms from Polynesia and Micronesia. Proceedings of the United States National Museum, 105 (3352), 65–82.

    Hyman, L.H. (1959) A further study of Micronesian polyclad flatworms. Proceedings of the United states National Museum, 108 (3410), 543–615.

    Jennings, J.B. (1971) Parasitism and commensalism in the Turbellaria. Advances in Parasitology, 9, 1–32.

    Kato, K. (1936) Notes on Paraplanocera. In:Prudhoe, S. (1945), XIX. On the species of the polyclad genus Paraplanocera. Annals and Magazine of Natural History, Series, 12 (87), 195–202.

    Ken-Ichi, T., Raj, U., Horiuchi, S. & Koshida, Y. (1991) Polyclad turbellarians collected on the Osaka University Expedition to Viti Levu, Fiji, in 1985, with remarks on distribution and phylogeny of the genus Discoplana. Hydrobiology, 227 (1), 333–339.

    Kenny, N.J., Noreña, C., Damborenea, C. & Granded, C. (2018) Probing recalcitrant problems in polyclad evolution and systematics with novel mitochondrial genome resources. Genomics, 2018, 1–13.

    Klautau, M., Russo, C.A.M, Lazoski, C., Boury-Esnault, N., Thorpe, J.P. & Solé-Cava, A.M. (1999). Does cosmopolitanism result from overconservative Systematics? A case study using the marine sponge Chondrilla nucula. Evolution, 53 (5), 1414–1422.

    Knowlton, N. (1993) Sibling species in the sea. Annual Review of Ecology and Systematics, 24, 189–216.

    Laidlaw, F.F. (1902) The marine Turbellaria, with an account of the anatomy of some species. Fauna and Geology of the Maldive and Laccadive Archipelagoes, 1, 282–312.

    Laidlaw, F.F. (1903a) IV. Suggestions for a revision of the classification of the Polyclad Turbellaria. Memoirs and Proceedings of the Manchester Literary and Philosophical Society, 48 (4), 1–16.

    Laidlaw, F.F. (1903b) On a collection of Turbellaria Polycladida from the Straits of Malacca. (Skeat Expedition 1899-1900). Proceedings of the Zoological Society of London, 1903, 301–318. Available from: (Accessed 15 Nov. 2019)

    Lamothe-Argumedo, R., García-Prieto, L., Osorio-Sarabia, D. & Ponce-de León, G. (1997) Catálogo de la Colección Nacional de Helmintos.Universidad Nacional Autónoma de México, Instituto de Biología y Comisión Nacional para el Conocimiento y Uso de la Biodiversidad, Ciudad de México, 211 pp. Available from: (Accessed 15 Nov. 2019)

    Lang, A. (1884) Die Polycladen (Seeplanarien) des Golfes von Neapel und der angrenzenden Meeresabschnitte. Eine Monographie. Fauna und Flora des Golfes von Neapel und der angrenzenden Meeresabschnitte, Leipzig, 11, 1–668.

    Lin, H.-N., Wang, K.-L., Wu, Z.-H., Tian, R.-M., Lui, G.-Z. & Xu, Y. (2017) Biological and chemical diversity of Bacteria associated with a marine flatworm. Marine Drugs, 15 (281), 1–14.

    Marcus, E. (1947) Turbelários marinhos do Brasil. Boletim da Faculdade de Filosofia, Ciências e Letras, Universidade de Sao Paulo, Zoologia, 13,111–243.

    Marcus, E. (1952) Turbellaria brasileiros (10). Boletim da Faculdade de Filosofia, Ciências e Letras, Universidade de Sao Paulo, Zoologia, 17, 5–187.

    McLean, J.H. (1970) Descriptions of a new genus and eight new species of Eastern Pacific Fissurellidae, with notes on other species. The Veliger, 12 (3), 362–367. Available from: (Accessed 15 Nov. 2019)

    Meixner, A. (1907) Polycladen von der Somaliküste, nebst einer Revision der Stylochinen. Zeitschrift für wissenschaftliche Zoologie, 8, 385–498. Available from: (Accessed 15 Nov. 2019)

    Menke, K.T. (1847) Verzeichniss einer Sendung von Conchylien von Mazatlan, mit einigen kritischen Bemerkungen. Zeitschrift für Malakozoologie, 4, 177–191.

    Meyer, F. (1922) Polycladen von Koseir (Rotes Meer). (Kollektion Professor Klunzinger). Archiv für Naturgeschichte, Berlin, Abt A, 87, 10, 138–158.

    Minot, C.S. (1876) Studien an Turbellarien. Beiträge zur Kenntnis der Plathelminthen. Arbeiten aus dem Zoologisch-Zootomischen Institut Würzburg, Hamburg, 3, 405–471.

    Newman, L.J. & Cannon, L.R.G. (1995) The importance of the fixation of colour, pattern and from in tropical Pseudocerotidae (Platyhelminthes, Polycladida). Hydrobiology, 305, 141–143.

    Newman, L.J. & Cannon, L.R.G. (1997) A new semi-terrestrial acotylean flatworm, Myoramyxa pardalota gen. et sp. nov. (Plehniidae, Polycladida) from southeast Queensland and Australia. Memoirs of the Queensland Museum, 42 (1), 311–314. []

    Newman, L.J. & Cannon, L.R.G. (2003) Marine flatworms, the world of Polyclads. CSIRO Publishing, Melbourne, 97 pp.

    Newman, L.J. & Schupp, P. (2002) A new species of pseudocerotid flatworm (Platyhelminthes, Polycladida) from the Indo-Pacific. Micronesia, 34 (2), 177–184. Available from: (Accessed 15 Nov. 2019)

    Palombi, A. (1928) Report on the Turbellaria. Zoological results of the Cambridge Expedition to the Suez Canal. 1924. Transactions of the Linnean Society of London, 22 (5), 579–630.

    Palumbi, S.R. (1997) Molecular biogeography of the Pacific. Coral Reefs, 16, 47–52.

    Philippi, R.A. (1846) Descriptions of a new species of Trochus and of eighteen new species of Littorina, in the collection of H. Cuming, 1872. Proceedings of the Zoological Society of London, 1845, 138–143.

    Philippi, R.A. (1849) Centuria altera testaceorum novorum. Zeitschrift für Malakozoologie, Year 5, 129–144.

    Pineda-López, R. & González-Bulnes, L. (1984) Turbelarios de México II. Descripción de un género y especie nuevos de policládidos ectocomensales de arqueogasterópodos del Pacífico mexicano. Universidad y Ciencia, 1 (1), 1–9.

    Plehn, M. (1896) Neue Polycladen, gesammelt von G. Chierchia bei der Erdumschiffung der Korvette Vettor Pisani von Hern Prof. Dr Kükenthal im nördlichen Eismeer und von Semon in Java. Jenaische Zeitschrift, 30, 137–176.

    Pritchard, M.H. & Kruse, G.O.W. (1982) The collection and preservation of animal parasites. University of Nebraska Press, Lincoln, Nebraska, 141 pp.

    Prudhoe, S. (1945) XIX. On the species of the polyclad genus Paraplanocera. Annals and Magazine of Natural History, Series 11, 12 (87), 195–202.

    Prudhoe, S. (1978) Some polyclad turbellarians new to the fauna of the Australia coasts. Records of the Australian Museum, 31 (14), 586–604.

    Prudhoe, S. (1985) A monograph on Polyclad Turbellaria. Oxford University Press, Oxford, 125 pp.

    Prudhoe, S. (1989) Polyclad turbellarians recorded from African waters. Bulletin of the British Museum of Natural History, 55, 47–96. Available from: (Accessed 15 Nov. 2019)

    Quiroga, Y.S., Bolaños, D.M. & Litvaitis, M.K. (2004) A checklist of polyclad flatworms (Platyhelminthes: Polycladida) from the Caribbean coast of Colombia, South America, Zootaxa, 633 (1), 1–12.

    Quiroga, Y.S., Bolaños, M. & Litvaitis, M.K. (2006) First description of deep-sea polyclad flatworms from the North Pacific: Anocellidus n. gen. profundus n. sp. (Anocellidae, n. fam.) and Oligocladus voightae n. sp. (Euryleptidae). Zootaxa, 1317 (1), 1–19.

    Rawlinson, K.A. (2008) Biodiversity of coastal polyclad flatworm assemblages in the wider Caribbean. Marine Biology, 153, 769–778.

    Rawlinson, K.A., Gillis, J.A., Billings, J. & Borneman, E.H. (2011) Taxonomy and life history of the Acropora-eating flatworm Amakusaplana acroporaenov. sp. (Polycladida: Prosthiostomidae). Coral Reefs, 30, 693–705.

    Schmarda, L.K. (1859) Neue wirbellose Thiere beobachtet und gesammelt auf einer Reise um die Erde 1853 bis 1857. Bd. I. Turbellarien, Rotatorien und Anneliden. Wirbellose Thiere. W. Engelmann, Leipzig, 66 pp.

    Sopott-Ehlers, B. & Schmidt, P. (1975) Interstitielle Fauna von Galapagos. XIV. Polycladida (Turbellaria). Microfauna Meeresbodens, 54, 193–222.

    Sowerby, I.G.B. (1825–1834) The genera of recent and fossil shells, for the use of students, in conchology and geology. Vol. 2. G. B. Sowerby, London, 262 pp. [pp. 127–162]

    Stimpson, W. (1857) Prodromus descriptionis animalium evertebratorum, quae in Expeditione ad Oceanum Pacificum Septentrionalem a Republica Federata missa, Johanne Rodgers Duce, observavit et descripsit. Pars I, Turbellaria Dendrocoela. Proceedings of the Academy of Natural Sciences of Philadelphia, 9, 19–31.

    Stummer-Traunfels, R. (1933) Polycladida. In: Bronn H.G. (Ed.), Klassen und Ordnungen des Tier-Reichs IV. Vermes. C. F. Winter, Leipzig and Heidelberg, pp. 3485–3596.