Abstract
Botryllus schlosseri is a widespread colonial ascidian commonly considered cosmopolitan and amply used as model for researches ranging from developmental biology to immunobiology. Recently, molecular data lead to hypothesize that the species named B. schlosseri may consist of more than a single taxon. Indeed, five highly divergent clades, named A-E, have been genetically identified and are referred as cryptic species. In this context, and lacking both a type and a detailed morphological description, we believe that it is necessary, as a taxonomic reference point, to designate a neotype and re-describe the species. Therefore, a sample from the Lagoon of Venice (Adriatic Sea, Italy) was deposited as neotype in the Natural History Museum of Venice (Italy), preserved both in formalin and in 90% ethanol. Here we provide a morphological description of the suggested neotype of B. schlosseri that takes into account several developmental stages (oozooid, zooid of first blastogenic generations, and mature zooid) and is carefully compared with the previous descriptions of samples coming from other European and non-European localities. Finally, we associate our morphological description to a “DNA barcode”, consisting in a long fragment of the mitochondrial COI gene. Our description is associated to clade A, although at now we cannot guarantee that this association is univocal.References
Ärnbäck-Christie-Linde, A. (1923) Northern and Arctic invertebrates in the collection of the Swedish State Museum (Riksmuseum). IX Tunicata. 2. Botryllidae: reproductive organs of Metrocarpa (n. gen.) leachi Savigny and Botryllus schlosseri (Pallas). Kungliga Svenska Vetenskaps-akademiens Handlingar, Stockholm, 63, 1–25.
Bancroft, F.W. (1903) Variation and fusion of colonies in compound ascidians. Proceedings of the Californian Academy of Science, 3, 137–186.
Berrill, N.J. (1941) The development of bud in Botryllus. Biological Bulletin, Woods Hole, 80, 169–184.
https://doi.org/10.2307/1537595Berrill, N.J. (1950) The Tunicata. With an account of the British species. The Ray Society, London, 354 pp.
Bock, D.G., MacIsaac, H.J. & Cristescu, M.E. (2012) Multilocus genetic analyses differentiate between widespread and spatially restricted cryptic species in a model ascidian. Proceedings of the Royal Society B, 279 (1737), 2377–2385.
https://doi.org/10.1098/rspb.2011.2610
Boyd, H.C., Brown, S.K., Harp, J.A. & Weissman, I.L. (1986) Growth and sexual maturation of laboratory-cultured Monterey Botryllus schlosseri. Biological Bulletin, 170, 91–109.
https://doi.org/10.2307/1541383Boyd, H.C., Weissman, I.L. & Saito, Y. (1990) Morphologic and genetic verification that Monterey Botryllus and Woods Hole Botryllus are the same species. Biological Bulletin, 178, 239–250.
https://doi.org/10.2307/1541825Brewin, B.I. (1946) Ascidians in the vicinity of the Portobello Marine Biological Station, Otago Harbour. Transaction of the Royal Society of New Zealand, 76, 87–131.
Brunetti, R. (1974) Observations on the life cycle of Botryllus schlosseri (Pallas) (Ascidiacea) in the Venetian Lagoon. Bollettino di Zoologia, 41, 225–251.
https://doi.org/10.1080/11250007409430119Brunetti, R. (2009) Botryllid species (Tunicata, Ascidiacea) from the Mediterranean coast of Israel, with some considerations on the systematics of Botryllinae. Zootaxa, 2289, 18–32.
Brunetti, R. (2010) Redescription of Botrylloides magnicoecum (Hartmeyer, 1912) based on the analysis of the type (Tunicata, Ascidiacea, Stielidae, Botryllinae). Bollettino del Museo di Storia Naturale di Venezia, 61, 45–58.
Brunetti, R., Beghi, L., Bressan, M. & Marin, M. (1980) Combined effects of temperature and salinity on colonies of Botryllus schlosseri and Botrylloides leachii (Ascidiacea) from the Venetian Lagoon. Marin Ecology Progress Series, 2, 303–314.
https://doi.org/10.3354/meps002303Brunetti, R. & Burighel, P. (1969) Sviluppo dell’apparato vascolare coloniale in Botryllus schlosseri (Pallas). Pubblicazioni della Stazione Zoologica di Napoli, 37 (Supplement 2), 137–148.
Brunetti, R. & Copello, M. (1978) Growth and senescence in colonies of Botryllus schlosseri (Pallas) (Ascidiacea). Bollettino di Zoologia, 45, 359–364.
https://doi.org/10.1080/11250007809440143Brunetti, R., Gissi, C., Pennati, R., Caicci, F., Gasparini, F. & Manni, L. (2015) Morphological evidence that the molecularly determined Ciona intestinalis type A and type B are different species: Ciona robusta and Ciona intestinalis. Journal of Zoologycal Systematic and Evolutionary Research, 53, 185–257.
https://doi.org/10.1111/jzs.12101
Brunetti, R., Marin, M., Beghi, L. & Bressan, M. (1983) Study of the pollution in the Venetian Lagoon's lower basin during the period 1974–1981. Rivista di Idrobiologia, 22, 27–58.
Brunetti, R. & Mastrototaro, F. (2012) Botrylloides pizoni, a new species of Botryllinae (ascidiacea) from the Mediterranean Sea. Zootaxa, 3258, 28–36.
Brunetti, R., Marin, M. & Bressan, M. (1984) Combined effects of temperature and salinity on sexual reproduction and colonial growth of Botryllus schlosseri (Tunicata). Bollettino di Zoologia, 51, 405–411.
https://doi.org/10.1080/11250008409439481Burighel, P. & Milanesi, C. (1973) Fine structure of the gastric epithelium of the ascidian Botryllus schlosseri. Vacuolated and zymogenic cells. Z. Zellforsch Mikrosk Anat, 145 (4), 541–555.
https://doi.org/10.1007/BF00306723Burighel, P. & Milanesi, C. (1977) Fine structure of the intestinal epithelium of the colonial ascidian Botryllus schlosseri. Cell Tissue Research, 182 (3), 357–369.
https://doi.org/10.1007/BF00219771Carlton, J.T. (2005) Setting ascidian invasions on the global stage. In: Proceedings of the International Invasive Sea Squirt Conference. Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, pp. ?????. [please cite the page range]
Cima, F., Ballarin, L., Caicci, F., Franchi, N., Gasparini, F., Rigon, F., Schiavon, F. & Manni, L. (2015) Life history and ecological genetics of the colonial ascidian Botryllus schlosseri. Zoologischer Anzeiger, 257, 54–70.
http://dx.doi.org/10.1016/j.jcz.2015.04.004
Colombera, D. (1969) The karyology of the colonial Ascidian Botryllus schlosseri (Pallas). Caryologia, 22, 339–349.
https://doi.org/10.1080/00087114.1969.10796353Colombera, D. (1970) A Squash Method for Chromosomes of Ascidians (Tunicata). Caryologia, 23 (1), 113–115.
https://doi.org/10.1080/00087114.1970.10796366
Gasparini, F., Manni, L., Cima, F., Zaniolo, G., Burighel, P., Caicci, F., Franchi, N., Schiavon, F., Rigon, F., Campagna, D. & Ballarin, L. (2015) Sexual and asexual reproduction in the colonial ascidian Botryllus schlosseri. Genesis, 53, 105–120.
https://doi.org/10.1002/dvg.22802
Gissi, C., Hastings, K.E.M., Gasparini, F., Stach, T., Pennati, R. & Manni, L. (2017) An unprecedented taxonomic revision of a model organism: the paradigmatic case of Ciona robusta and Ciona intestinalis. Zoologica Scripta, 46 (5), 521–522. https://doi.org/10.1111/zsc.12233
Griggio, F., Voskoboynik, A., Iannelli, F., Justy, F., Tilak, M.K., Turon, X., Pesole, G., Douzery, E. J., Mastrototaro, F. & Gissi, C. (2014) Ascidian mitogenomics: comparison of evolutionary rates in closely related taxa provides evidence of ongoing speciation events. Genome Biology and Evolution, 6 (3), 591–605.
https://doi.org/10.1093/gbe/evu041
Harant, H. & Vernières, P. (1933) Tuniciers: I Ascidies. Faune de France, 27, 1–100.
Hebert, P.D., Cywinska, A., Ball, S.L. & deWaard, J.R. (2003) Biological identifications through DNA barcodes. Proceeding of the Biological Science, 270 (1512), 313–321.
https://doi.org/10.1098/rspb.2002.2218
Herdman, E.C. (1924) Botryllus. L.M.B.C. Memoires on Typical British Marine Plants & Animals, XXVI. University Press Liverpool, Liverpool, 40 pp.
Herdman, W.A. (1891) A revised classification of the Tunicata. The Journal of the Linnean Society. Zoology, XXIII, 558–673.
https://doi.org/10.1111/j.1096-3642.1891.tb02403.xHirose, M. & Hirose, E. (2009) DNA barcoding in photosymbiotic species of Diplosoma (Ascidiacea: Didemnidae), with the description of a new species from the southern Ryukyus, Japan. Zoological Science, 26 (8), 564–568.
https://doi.org/10.2108/zsj.26.564Kott, P.M. (1985) The Australian Ascidiacea. Part I, Phlebobranchia and Stolidobranchia. Memoirs of the Queensland Museum, 23, 1–440.
ICZN, International Commission on Zoological Nomenclature (1999) International Code of Zoological Nomenclature. 4th Edition. The International Trust for Zoological Nomenclature, London, XXIX + 306 pp. [http://www.iczn.org/code]
Lacoursiere-Roussel, A., Bock, D.G., Cristescu, M.E., Guichard, F., Girard, P., Legendre, P. & McKindsey, C.W. (2012) Disentangling invasion processes in a dynamic shipping-boating network. Molecular Ecology, 21 (17), 4227–4241.
https://doi.org/10.1111/j.1365-294X.2012.05702.xLauzon, R.J., Brown, C., Kerr, L. & Tiozzo, S. (2013) Phagocyte dynamics in a highly regenerative urochordate: insights into development and host defense. Developmental Biology, 374, 357–373.
https://doi.org/10.1016/j.ydbio.2012.11.006Lejeusne, C., Bock, D.G., Therriault, T.W., MacIsaac, H. J. & Cristescu, M.E. (2011) Comparative phylogeography of two colonial ascidians reveals contrasting invasion histories in North America. Biological Invasions, 13, 635–650.
https://doi.org/10.1007/s10530-010-9854-0
Lopez-Legentil, S., Legentil, M.L., Erwin, P.M. & Turon, X. (2015) Harbor networks as introduction gateways: contrasting distribution patterns of native and introduced ascidians. Biological Invasions, 17 (6), 1623–1638.
https://doi.org/10.1007/s10530-014-0821-z
Lopez-Legentil, S., Turon, X. & Planes, S. (2006) Genetic structure of the star sea squirt, Botryllus schlosseri, introduced in southern European harbours. Molecular Ecology, 15 (13), 3957–3967.
https://doi.org/10.1111/j.1365-294X.2006.03087.x
Manni, L., Gasparini, F., Hotta, K., Ishizuka, K. J., Ricci, L., Tiozzo, S., Voskoboynik, A. & Dauga, D. (2014) Ontology for the asexual development and anatomy of the colonial chordate Botryllus schlosseri. PLoS One, 9 (5), e96434.
https://doi.org/10.1371/journal.pone.0096434
Manni, L., Zaniolo, G., Cima, F., Burighel, P. & Ballarin, L. (2007) Botryllus schlosseri: A model ascidian for the study of asexual reproduction. Developmental Dynamics, 236 (2), 335–352.
https://doi.org/10.1002/dvdy.21037Meenakshi, V.K. & Senthamarai, S. (2006) First report on two species of ascidians to represent the genus Botryllus Gaertner, 1774 from Indian waters. Journal of the Marine Biological Association of India, 48 (1), 100–102.
Michaelsen W. (1921) Die Botrylliden und Didemniden der Nordsee und der zur Ostsee fuhrenden Meeresgebiete. In: Wissenschaftliche Meeresuntersuchungen, herausgegeben von der Kommission zur Untersuchung der deutschen Meere in Kiel und der Biologischen Anstalt auf Helgoland, 14, 97–124.
Milkman, R. (1967) Genetic and Developmental Studies on Botryllus schlosseri. Biological Bulletin, 132 (2), 229–243.
https://doi.org/10.2307/1539891Millar, R.H. (1955) On a collection of ascidians from South Africa. Proceedings of the Zoological Society of London, 125, 169–221.
https://doi.org/10.1111/j.1096-3642.1955.tb00597.xMillar, R.H. (1966) Ascidiacea. Marine Invertebrates of Scandinavia, No 1, 1–123.
Millar, R.H. (1970) British Ascidians. Synopses of the British Fauna, New Series, 1, 1–88.
Millar, R.H. (1982) The Marine Fauna of New Zealand: Ascidiacea. New Zealand Oceanographic Institute Memoir, 85, 1–117.
Monniot, C. (1991) Ascidies de Nouvelle-Caledonie. 10. Stolidobranches. Bullettin du Muséum National d’Histoire Naturelle, Paris, 13, 3–37
Nishikawa, T. (1991) The Ascidians of the Japan Sea. II. Publications of the Seto Marine Biological Laboratory, 35 (1/3), 25–170.
https://doi.org/10.5134/176172Nydam, M.L., Giesbrecht, K.B. & Stephenson, E.E. (2017) Origin and dispersal history of two colonial ascidian clades in the Botryllus schlosseri species complex. PLoS One, 12 (1), e0169944.
https://doi.org/10.1371/journal.pone.0169944
Okuyama, M. & Saito, Y. (2001) Studies on Japanese botryllid ascidians. I. A new species of the genus Botryllus from the Izu Islands. Zoological Science, 18, 261–267.
https://doi.org/10.2108/zsj.18.261Okuyama, M. & Saito, Y. (2002) Studies on Japanese botryllid ascidians. II. A new species of the genus Botryllus from the vicinity of Shimoda. Zoological Science, 19, 809–815.
https://doi.org/10.2108/zsj.19.809Pallas, P.S. (1766) Elenchus zoophytorum sistens generum adumbrationes generaliores et specierum cognitarum succintas descriptiones, cum selectis auctorum synonymis. Franciscum Varrentrapp, Hagae-comitum, 451 pp.
https://doi.org/10.5962/bhl.title.6595Pennati, R., Ficetola, G. F., Brunetti, R., Caicci, F., Gasparini, F., Griggio, F., Sato, A., Stach, T., Kaul-Strehlow, S., Gissi, C. & Manni, L. (2015) Morphological differences between larvae of the Ciona intestinalis Species complex: hints for a valid taxonomic definition of distinct species. PLoS One, 10 (5), e0122879. https://doi.org/10.1371/journal.pone.0122879
Pérez-Portela, R., Bishop, J.D., Davis, A.R. & Turon, X. (2009) Phylogeny of the families Pyuridae and Styelidae (Stolidobranchiata, Ascidiacea) inferred from mitochondrial and nuclear DNA sequences. Molecular Phylogenetics and Evolution, 50 (3), 560–570.
https://doi.org/10.1016/j.ympev.2008.11.014
Reem, E., Douek, J., Paz, G., Katzir, G. & Rinkevich, B. (2017) Phylogenetics, biogeography and population genetics of the ascidian Botryllus schlosseri in the Mediterranean Sea and beyond. Molecular Phylogenetic and Evolution, 107, 221–231. https://doi.org/10.1016/j.ympev.2016.10.005
Rho, B.J. (1971) A study on the classification and the distribution of the Korean Ascidians. The journal of Korean Research Institute for Better Living, 6, 103–153.
Rho, B.J. (1995) The Ascidians (Tunicata) from Chindo Islands, Korea. The Korean Journal of Systematic Zoology, 11 (1), 125–145.
Rho, B.J. & Lee, J. (1989) A systematic study on the Ascidians from Cheju Island, Korea. The Korean Journal of Systematic Zoology, 5 (1), 59–76.
Rinkevich, B. & Shapira, M. (1998) An improved diet for inland bloodstock and the establishment of an inbred line from Botryllus schlosseri, a colonial sea squirt (Ascidiacea). Aquatic Living Resources, 11 (3), 163–171.
https://doi.org/10.1016/S0990-7440(98)80113-7Rondeletius, G., (1555) Universae aquatilium Historiae…Libri de Piscibus marinis. Vol. II. Cap XXV. De Uva marina, Ludguni, 130 pp.
Sabbadin, A. (1955a) Osservazioni sullo sviluppo, l’accrescimento e la riproduzione di Botryllus schlosseri (Pallas), in condizioni di laboratorio. Bollettino di Zoologia, 22, 243–263.
Sabbadin, A. (1955b) Il ciclo Biologico di Botryllus schlosseri (Pallas) nella Laguna di Venezia. Estratto dell’archivio di Oceanografia e Limnologia, X, 217–231.
Sabbadin, A. (1960) Ulteriori notizie sull’allevamento e sulla biologia dei Botrilli in condizioni di laboratorio. Archivio di Oceanografia e Limnologia, 12, 97–107.
Sabbadin, A. (1969) The compound ascidian Botryllus schlosseri in the field and in laboratory. Pubblicazioni della Stazione Zoologica di Napoli, 37 (Supplement 2), 67–72.
Saito, Y. (2003) Xenogeneic rejecton among three botryllids (Compound Ascidians). Zoological Science, 20, 581–589.
Saito, Y. & Okuyama, M. (2003) Studies on Japanese botryllid ascidians. IV. A new species of the genus Botryllus with a unique colony shape, from the vicinity of Shimoda. Zoological Science, 20 (9), 1153–1161.
http://dx.doi.org/10.2108/zsj.20.1153Saito, Y., Mukai, H. & Watanabe, H. (1981a) Studies on Japanese compound styelid ascidians. I. Two new species of the genus Botryllus from the vicinity of Shimoda. Publications of the Seto Marin Biological Laboratory, 26, 347–355.
https://doi.org/10.5134/176033Saito, Y., Mukai, H. & Watanabe, H. (1981b) Studies on Japanese compound styelid ascidians. II. A new species of the genus Botrylloides and redescription of B. violaceus Oka. Publications of the Seto Marin Biological Laboratory, 26, 357–368.
https://doi.org/10.5134/176032Saito, Y. & Nagasawa, N. (2003) Studies on Japanese botryllid ascidians. III. A new species of the genus Botryllus with a vivid colony color from the vicinity of Shimoda. Zoological Science, 20, 765–771.
https://doi.org/10.2108/zsj.20.765Saito, Y., Shirae, M., Okuyama, M. & Cohen, S.H. (2001) Phylogeny of Botryllid Ascidians. In: Sawada, H. (Ed.), The Biology of Ascidians. Springer, Tokio, pp. 315–320.
https://doi.org/10.1007/978-4-431-66982-1_50Saito, Y. & Watanabe, H. (1985) Studies on Japanese compound styelid ascidians. IV. Three new species of the genus Botrylloides from the vicinity of Shimoda. Publications of the Seto Marin Biological Laboratory, 30, 227–240.
https://doi.org/10.5134/176112Savigny, J.C. (1816) Mémoires sur les animaux sans vertèbres. Pt. 2. GDufour, Paris, 232 pp.
Schlosser, J.A. & Ellis, J. (1755) An account of curious, fleshy, coral-like substance. Philosophical Transactions of the Royal Society of London, 49, 449–452.
https://doi.org/10.1098/rstl.1755.0062Stach, T. & Turbeville, J. M. (2002) Phylogeny of Tunicata inferred from molecular and morphological characters. Molecular Phylogenetic and Evolution, 25 (3), 408–428.
https://doi.org/10.1016/S1055-7903(02)00305-6Tokioka, T. (1951) The Fauna of Akkeshi Bay. XVIII: Ascidia. Publications from the Akkeshi Marine Biological Station, 1, 1–22.
Tokioka, T. (1953) Ascidians of Sagami Bay. Iwanami Shoten, Tokyo, 313 pp.
Tokioka, T. (1967) Contributions to Japanese ascidian fauna XXII. Ascidians from Sado Island. Publications of the Seto Marine Biological Laboratory, XV, 239–244.
https://doi.org/10.5134/175465Van Name, W.G. (1945) The North and South American Ascidians. Bulletin of the American Museum of Natural History, 84, 1–476.
Voskoboynik, A., Neff, N.F., Sahoo, D., Newman, A.M., Pushkarev, D., Koh, W., Passarelli, B., Fan, H.C., Mantalas, G.L., Palmeri, K.J., Ishizuka, K.J., Gissi, C., Griggio, F., Ben-Shlomo, R., Corey, D.M., Penland, L., White, R.A., Weissman, I.L. & Quake, S.R. (2013) The genome sequence of the colonial chordate, Botryllus schlosseri. Elife, 2, e00569.
https://doi.org/10.7554/eLife.00569Voskoboynik, A. & Weissman, I.L. (2015) Botryllus schlosseri, an emerging model for the study of aging, stem cells, and mechanisms of regeneration. Invertebrate Reproduction & Devevolpment, 59 (Supplement 1), 33–38.
https://doi.org/10.1080/07924259.2014.944673
Yund, P.O., Collins, C. & Johnson, S.L. (2015) Evidence of a native northwest atlantic COI haplotype clade in the cryptogenic colonial ascidian Botryllus schlosseri. Biological Bulletin, 228 (3), 201–216.
https://doi.org/10.1086/BBLv228n3p201
Zaniolo, G., Burighel, P. & Martinucci, G.B. (1987) Ovulation and placentation in Botryllus schlosseri (Ascidiacea): an ultrastructural study. Canadian Journal of Zoology, 65, 1181–1190.
https://doi.org/10.1139/z87-183