Palythoa is a genus of anthozoans in the order Zoantharia.Reimer, J. (2018). Palythoa Lamouroux, 1816. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=205785 on 2018-08-27Myers, P., R. Espinosa, C. S. Parr, T. Jones, G. S. Hammond, and T. A. Dewey. 2014. The Animal Diversity Web (online). Accessed at http://animaldiversity.org/accounts/Palythoa/classification/
Description The polyps of Palythoa are partially embedded in an encrusting mat of tissue (coenenchyme) covering the substrate on which the colony grows. The individual polyps have flattened oral discs surrounded by a fringe of tentacles. The tentacles' shape and size can vary considerably between species, and even between colonies of the same species. Their colors are also highly variable, with relatively dull shades like cream, coffee, white, brown, or yellow, being the most common. Bright green colonies also exist, but these are more rare.
Palytoxin Palytoxin is a highly toxic natural product found in many (but not all) members of the genus Palythoa. The substance was first isolated from the seaweed-like "limu-make-o-Hana" ("Seaweed of Death from Hana") in 1971 in Hawaii. Scientific investigation of the seaweed found it to be a colonial cnidarian, which was classified as a zoanthid and named Palythoa toxica.
The presence of this toxin is of significance to aquarists who keep reef aquariums, as Palythoa and related zoanthids are commonly kept as display specimens in marine aquaria. Aquarists have reported symptoms consistent with palytoxin poisoning prior to having exposure to zoanthids suspected to contain the toxin. One report involved an aquarist being accidentally poisoned through skin injuries after handling various zoanthids.Katrin Hoffmann, Maren Hermanns-Clausen, Claus Buhl, Markus W. Büchler, Peter Schemmer, Dietrich Mebs and Silke Kauferstein (2008) A case of palytoxin poisoning due to contact with zoanthid corals through a skin injury. Toxicon 51, no. 8: 1535-1537. Another report involved an aquarium hobbyist in Virginia who experienced a severe respiratory reaction after trying to eradicate colonies of a brown zoanthid (suspected to be Palythoa) from rocks in their aquarium. A 2010 study found that a single specimen of Palythoa from a sample of fifteen colonies purchased from three aquarium stores in the Washington D.C. area contained high levels of palytoxin, indicating that toxic individuals are occasionally present in the captive population.Deeds JR, Handy SM, White KD, Reimer JD (2011) Palytoxin Found in Palythoa sp. Zoanthids (Anthozoa, Hexacorallia) Sold in the Home Aquarium Trade. PLoS ONE 6(4): e18235.
While poisoning events have occurred, they are exceedingly rare, and many reef hobbyists have kept Palythoa without any adverse reactions.
It is generally recommended to always wear appropriate protective gloves and goggles when maintaining aquaria.Nicholas Violand Aquarium Science: Palytoxin and You, Tropical Fish Hobbyist Magazine
Taxonomy and systematics The genus Protopalythoa was once thought to be distinct from the genus Palythoa but is now considered to be a synonym.
Species The following species are recognized in the genus Palythoa:
Palythoa aggregata Lesson, 1830 Palythoa anneae Carlgren, 1938 Palythoa anthoplax Pax & Müller, 1957¹ Palythoa arenacea Heller, 1868 Palythoa argus Ehrenberg, 1834 Palythoa aspera Pax, 1909 Palythoa atogrisea Pax, 1924 Palythoa australiae Carlgren, 1937¹ Palythoa australiensis Carlgren, 1950 Palythoa bertholeti Gray, 1867 Palythoa brasiliensis Heider, 1899 Palythoa braunsi Pax, 1924 Palythoa brochi Pax, 1924 Palythoa buitendijkl Pax, 1924 Palythoa caesia Dana, 1846 Palythoa calcaria Muller, 1883 Palythoa calcigena Pax, 1924 Palythoa calycina Pax, 1909 Palythoa canalifera Pax, 1908 Palythoa canariensis Haddon & Duerden, 1896 Palythoa cancrisocia Martens, 1876 Palythoa capensis Haddon & Duerden, 1896¹ Palythoa caracasiana Pax, 1924 Palythoa caribaeorum (Duchassaing & Michelotti, 1860) Palythoa ceresina Pax & Muller, 1956 Palythoa chlorostoma Pax & Muller, 1956 Palythoa cingulata Milne Edwards, 1857 Palythoa clavata (Duchassaing, 1850) Palythoa complanata Carlgren, 1951¹ Palythoa congoensis Pax, 1952 Palythoa dartevellei Pax, 1952 Palythoa densa Carlgren, 1954¹ Palythoa denudata Dana, 1846 Palythoa dura Carlgren, 1920 Palythoa durbanensis Carlgren, 1938¹ Palythoa dysancrita Pax & Muller, 1956 Palythoa eremita Pax, 1920 Palythoa fatua Schultze, 1867 Palythoa flavoviridis Ehrenberg, 1834 Palythoa fuliginosa Dana, 1846 Palythoa fusca (Duerden, 1898) Palythoa glareola (Lesueur, 1817) Palythoa glutinosa Duchassaing & Michelotti, 1864 Palythoa grandiflora (Verrill, 1900) Palythoa grandis (Verrill, 1900) Palythoa gregorii Haddon & Duerden, 1896 Palythoa gridellii Pax & Muller, 1956 Palythoa guangdongensis Zunan, 1998¹ Palythoa guinensis von Koch, 1886¹ Palythoa haddoni Carlgren, 1937¹ Palythoa halidosis Pax, 1952 Palythoa hartmeyeri Pax, 1910 Palythoa heideri Carlgren, 1954¹ Palythoa heilprini (Verrill, 1900) Palythoa heliodiscus (Ryland & Lancaster, 2003) Palythoa horstii Pax, 1924 Palythoa howesii Haddon & Shackleton, 1891¹ Palythoa hypopelia Pax, 1909 Palythoa ignota Carlgren, 1951 Palythoa incerta Carlgren, 1900 Palythoa insignis Carlgren, 1951 Palythoa irregularis Duchassaing & Michelotti, 1860 Palythoa isolata Verrill, 1907 Palythoa javanica Pax, 1924 Palythoa kochii Haddon & Shackleton, 1891 Palythoa leseuri Klunzinger, 1877 Palythoa leucochiton Pax & Muller, 1956 Palythoa liscia Haddon & Duerden, 1896 Palythoa mammillosa (Ellis & Solander, 1786) Palythoa mizigama Irei, Sinniger & Reimer, 2015 Palythoa monodi Pax & Muller, 1956 Palythoa multisulcata Carlgren, 1900¹ Palythoa mutuki (Haddon & Shackleton, 1891) Palythoa natalensis Carlgren, 1938 Palythoa nelliae Pax, 1935 Palythoa nigricans McMurrich, 1898 Palythoa oorti Pax, 1924 Palythoa psammophilia Walsh & Bowers, 1971 Palythoa senegalensis Pax & Muller, 1956 Palythoa senegambiensis Carter, 1882 Palythoa shackletoni Carlgren, 1937 Palythoa sinensis Zunan, 1998¹ Palythoa singaporensis Pax & Müller, 1956¹ Palythoa spongiosa Andres, 1883 Palythoa stephensoni Carlgren, 1937¹ Palythoa texaensis Carlgren & Hedgpeth, 1952 Palythoa titanophila Pax & Müller, 1957¹ Palythoa toxica Walsh & Bowers, 1971 Palythoa tropica Carlgren, 1900 Palythoa tuberculosa (Esper, 1791) Palythoa umbrosa Irei, Sinniger & Reimer, 2015 Palythoa variabilis (Duerden, 1898) Palythoa vestitus (Verrill, 1928) Palythoa wilsmoorei Wilsmore¹ Palythoa xishaensis Zunan, 1998¹ Palythoa yongei Carlgren, 1937¹ Palythoa zanzibarica Carlgren¹
¹Indicates Species Unreviewed: has not been verified by a taxonomic editor
Taxon inquirendum: Palythoa anduzii (Duchassaing & Michelotti, 1860) Palythoa auricula (Lesueur, 1817) Palythoa brevis Andres, 1883 Palythoa casigneta Walsh, 1967 Palythoa distans (Duchassaing & Michelotti, 1866) Palythoa dubiae Walsh, 1967 Palythoa eupaguri Marion, 1882 Palythoa fulva Walsh, 1967 Palythoa fulva (Quoy & Gaimard, 1833) Palythoa gigantea Cubit & Williams, 1983 Palythoa glomerata Marion, 1882 Palythoa lutea (Quoy & Gaimard, 1833) Palythoa mcmurrichi (Haddon & Shackleton, 1891) Palythoa olivascens Brandt, 1835 Palythoa plana (Duchassaing & Michelotti, 1860) Palythoa vanikorensis (Quoy & Gaimard, 1833) Palythoa viridifusca (Quoy & Gaimard, 1833) Palythoa viridis (Quoy & Gaimard, 1833)
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