Morske zmije, ili zmije koralnog grebena, su potporodica otrovnih elapidnih zmija, -{Hydrophiinae}-, koje nastanjuju morske sredine tokom većeg dela ili celokupnog života. Većina njih je dobro prilagođena potpuno vodenom životu i ne mogu se kretati kopnom, osim roda -{Laticauda}-, koji ima ograničeno kretanje kopnom. One se nalaze se u toplim obalskim vodama od Indijskog do Tihog okeana i usko su povezane sa otrovnim kopnenim zmijama u Australiji.

Sve morske zmije imaju repove nalik veslu, a mnoge imaju bočno komprimovana tela koja im daju izgled jegulja. Za razliku od riba, nemaju škrge i moraju redovno da izrone da bi disale. Zajedno s kitovima, spadaju u najpotpunije vodene životinje od svih kičmenjaka koji dišu vazduh.Parker HW, Grandison AGC. 1977. Snakes – a natural history. Second Edition. British Museum (Natural History) and Cornell University Press. 108 pp. 16 plates. LCCCN 76-54625. (cloth), (paper). Neke od vrsta ove grupe imaju najmoćnije otrove od svih zmija. Deo njih ima blage dispozicije i ugrizaju samo kad su provocirane, dok su druge puno agresivnije. Trenutno je 17 rodova morskih zmija opisano.Elapidae at the New Reptile Database. Accessed 12 August 2007.

Sistematika Rodovi -{Acanthophis Daudin, 1803}- -{Aipysurus Lacépède, 1804}- -{Antaioserpens Wells and Wellington, 1985}- -{Aspidomorphus Fitzinger, 1843}- -{Austrelaps Worrell, 1963}- -{Brachyurophis Günther, 1863}- -{Cacophis Günther, 1863}- -{Cryptophis Worrell, 1961}- -{Demansia Günther, 1858}- -{Denisonia Krefft, 1869}- -{Drysdalia Worrell, 1961}- -{Echiopsis Fitzinger, 1843}- -{Elapognathus Boulenger, 1896}- -{Emydocephalus Krefft, 1869}- -{Ephalophis M. A. Smith, 1931}- -{Furina A. M. C. Duméril, 1853}- -{Hemiaspis Fitzinger, 1861}- -{Hoplocephalus Wagler, 1830}- -{Hydrelaps Boulenger, 1896}- -{Hydrophis Latreille in Sonnini and Latreille, 1801}- -{Kolpophis M. A. Smith, 1926}- -{Loveridgelaps McDowell, 1970}- -{Micropechis Boulenger, 1896}- -{Neelaps Günther, 1863}- -{Notechis Boulenger, 1896}- -{Ogmodon W. C. H. Peters, 1864}- -{Oxyuranus Kinghorn, 1923}- -{Parahydrophis Burger and Natsuno, 1974}- -{Parapistocalamus Roux, 1934}- -{Parasuta Worrell, 1961}- -{Paroplocephalus Keogh, Scott and Scanlon, 2000}- -{Pseudechis Wagler, 1830}- -{Pseudonaja Günther, 1858}- -{Rhinoplocephalus F. Müller, 1885}- -{Salomonelaps McDowell, 1970}- -{Simoselaps Jan, 1859}- -{Suta Worrell, 1961}- -{Thalassophis P. Schmidt, 1852}- -{Toxicocalamus Boulenger, 1896}- -{Tropidechis Günther, 1863}- -{Vermicella Gray in Günther, 1858}-

Vrste -{Acanthophis antarcticus (Shaw and Nodder, 1802)}- -{Acanthophis cryptamydros Maddodk, Ellis, Doughty, A. Smith and Wüster, 2015}- -{Acanthophis hawkei Wells and Wellington, 1985}- -{Acanthophis laevis Macleay, 1878}- -{Acanthophis praelongus Ramsay, 1877}- -{Acanthophis pyrrhus Boulenger, 1898}- -{Acanthophis rugosus Loveridge, 1948}- -{Acanthophis wellsi Hoser, 1998}- -{Aipysurus apraefrontalis M. A. Smith, 1926}- -{Aipysurus duboisii Bavay, 1869}- -{Aipysurus eydouxii (Gray, 1849)}- -{Aipysurus foliosquama M. A. Smith, 1926}- -{Aipysurus fuscus (Tschudi, 1837)}- -{Aipysurus laevis Lacépède, 1804}- -{Aipysurus mosaicus Sanders, Rasmussen, Elmburg, Mumpuni, Guinea, Blias, Lee and Fry, 2012}- -{Aipysurus pooleorum L. A. Smith, 1974}- -{Aipysurus tenuis Lönnberg and Andersson, 1913}- -{Antaioserpens albiceps (Boulenger, 1898)}- -{Antaioserpens warro (De Vis, 1884)}- -{Aspidomorphus lineaticollis (Werner, 1903)}- -{Aspidomorphus muelleri (Schlegel, 1837)}- -{Aspidomorphus schlegelii (Günther, 1872)}- -{Austrelaps labialis (Jan, 1859)}- -{Austrelaps ramsayi (Krefft, 1864)}- -{Austrelaps superbus (Günther, 1858)}- -{Brachyurophis approximans (Glauert, 1954)}- -{Brachyurophis australis (Krefft, 1864)}- -{Brachyurophis campbelli (Kinghorn, 1929)}- -{Brachyurophis fasciolatus (Günther, 1872)}- -{Brachyurophis incinctus (Storr, 1968)}- -{Brachyurophis morrisi (Horner, 1998)}- -{Brachyurophis roperi (Kinghorn, 1931)}- -{Brachyurophis semifasciatus Günther, 1863}- -{Cacophis churchilli Wells and Wellington, 1985}- -{Cacophis harriettae Krefft, 1869}- -{Cacophis krefftii Günther, 1863}- -{Cacophis squamulosus (A. M. C. Duméril, Bibron and A. H. A. Duméril, 1854)}- -{Cryptophis boschmai (Brongersma and Knaap-van Meeuwen, 1964)}- -{Cryptophis incredibilis (Wells and Wellington, 1985)}- -{Cryptophis nigrescens (Günther, 1862)}- -{Cryptophis nigrostriatus (Krefft, 1864)}- -{Cryptophis pallidiceps (Günther, 1858)}- -{Demansia angusticeps (Macleay, 1888)}- -{Demansia calodera Storr, 1978}- -{Demansia flagellatio Wells and Wellington, 1985}- -{Demansia olivacea (Gray, 1842)}- -{Demansia papuensis (Macleay, 1877)}- -{Demansia psammophis (Schlegel, 1837)}- -{Demansia quaesitor Shea in Shea and Scanlon, 2007}- -{Demansia reticulata (Gray, 1842)}- -{Demansia rimicola Scanlon in Shea and Scanlon, 2007}- -{Demansia rufescens Storr, 1978}- -{Demansia shinei Shea in Shea and Scanlon, 2007}- -{Demansia simplex Storr, 1978}- -{Demansia torquata (Günther, 1862)}- -{Demansia vestigiata (De Vis, 1884)}- -{Denisonia devisi Waite and Longman, 1920}- -{Denisonia maculata (Steindachner, 1867)}- -{Drysdalia coronoides (Günther, 1858)}- -{Drysdalia mastersii (Krefft, 1866)}- -{Drysdalia rhodogaster (Jan in Jan and Sordelli, 1873)}- -{Echiopsis curta (Schlegel, 1837)}- -{Elapognathus coronatus (Schlegel, 1837)}- -{Elapognathus minor (Günther, 1863)}- -{Emydocephalus annulatus Krefft, 1869}- -{Emydocephalus ijimae Stejneger, 1898}- -{Emydocephalus szczerbaki Dotsenko, 2011}- -{Ephalophis greyae M. A. Smith, 1931}- -{Furina barnardi (Kinghorn, 1939)}- -{Furina diadema (Schlegel, 1837)}- -{Furina dunmalli (Worrell, 1955)}- -{Furina ornata (Gray, 1842)}- -{Furina tristis (Günther, 1858)}- -{Hemiaspis damelii (Günther, 1876)}- -{Hemiaspis signata (Jan, 1859)}- -{Hoplocephalus bitorquatus (Jan, 1859)}- -{Hoplocephalus bungaroides (Schlegel, 1837)}- -{Hoplocephalus stephensii Krefft, 1869}- -{Hydrelaps darwiniensis Boulenger, 1896}- -{Hydrophis atriceps Günther, 1864}- -{Hydrophis belcheri (Gray, 1849)}- -{Hydrophis bituberculatus W. C. H. Peters, 1873}- -{Hydrophis brookii Günther, 1872}- -{Hydrophis caerulescens (Shaw, 1802)}- -{Hydrophis cantoris Günther, 1864}- -{Hydrophis coggeri (Kharin, 1984)}- -{Hydrophis curtus (Shaw, 1802)}- -{Hydrophis cyanocinctus Daudin, 1803}- -{Hydrophis czeblukovi (Kharin, 1984)}- -{Hydrophis donaldi Ukuwela, Sanders and Fry, 2012}- -{Hydrophis elegans (Gray, 1842)}- -{Hydrophis fasciatus (Schneider, 1799)}- -{Hydrophis gracilis (Shaw, 1802)}- -{Hydrophis hardwickii (Gray, 1835)}- -{Hydrophis hendersoni (Boulenger, 1903)}- -{Hydrophis inornatus (Gray, 1849)}- -{Hydrophis jerdonii (Gray, 1849)}- -{Hydrophis kingii Boulenger, 1896}- -{Hydrophis klossi Boulenger, 1912}- -{Hydrophis laboutei Rasmussen and Ineich, 2000}- -{Hydrophis lamberti M. A. Smith, 1917}- -{Hydrophis lapemoides (Gray, 1849)}- -{Hydrophis macdowelli Kharin, 1983}- -{Hydrophis major (Shaw, 1802)}- -{Hydrophis mamillaris (Daudin, 1803)}- -{Hydrophis melanocephalus Gray, 1849}- -{Hydrophis melanosoma Günther, 1864}- -{Hydrophis nigrocinctus Daudin, 1803}- -{Hydrophis obscurus Daudin, 1803}- -{Hydrophis ocellatus Gray, 1849}- -{Hydrophis ornatus (Gray, 1842)}- -{Hydrophis pachycercos Fischer, 1855}- -{Hydrophis pacificus Boulenger, 1896}- -{Hydrophis parviceps M. A. Smith, 1935}- -{Hydrophis peronii (A. M. C. Duméril, 1853)}- -{Hydrophis platurus (Linnaeus, 1766)}- -{Hydrophis schistosus Daudin, 1803}- -{Hydrophis semperi Garman, 1881}- -{Hydrophis sibauensis Rasmussen, Auliya and Böhme, 2001}- -{Hydrophis spiralis (Shaw, 1802)}- -{Hydrophis stokesii (Gray, 1846)}- -{Hydrophis stricticollis Günther, 1864}- -{Hydrophis torquatus Günther, 1864}- -{Hydrophis viperinus (P. Schmidt, 1852)}- -{Hydrophis vorisi Kharin, 1984}- -{Hydrophis zweifeli (Kharin, 1985)}- -{Kolpophis annandalei (Laidlaw, 1901)}- -{Loveridgelaps elapoides (Boulenger, 1890)}- -{Micropechis ikaheca (Lesson in Duperrey, 1829)}- -{Neelaps calonotus (A. M. C. Duméril, Bibron and A. H. A. Duméril, 1854)}- -{Notechis scutatus (W. C. H. Peters, 1861)}- -{Ogmodon vitianus W. C. H. Peters, 1864}- -{Oxyuranus microlepidotus (McCoy, 1879)}- -{Oxyuranus scutellatus (W. C. H. Peters, 1867)}- -{Oxyuranus temporalis Doughty, Maryan, Donnellan and Hutchinson, 2007}- -{Parahydrophis mertoni (Roux, 1910)}- -{Parapistocalamus hedigeri Roux, 1934}- -{Parasuta dwyeri (Worrell, 1956)}- -{Parasuta flagellum (McCoy, 1878)}- -{Parasuta gouldii (Gray, 1841)}- -{Parasuta monachus (Storr, 1964)}- -{Parasuta nigriceps (Günther, 1863)}- -{Parasuta spectabilis (Krefft, 1869)}- -{Paroplocephalus atriceps (Storr, 1980)}- -{Pseudechis australis (Gray, 1842)}- -{Pseudechis butleri L. A. Smith, 1982}- -{Pseudechis colletti Boulenger, 1902}- -{Pseudechis guttatus De Vis, 1905}- -{Pseudechis pailsei (Hoser, 1998)}- -{Pseudechis papuanus W. C. H. Peters and Doria, 1878}- -{Pseudechis porphyriacus (Shaw, 1794)}- -{Pseudechis rossignolii (Hoser, 2000)}- -{Pseudechis weigeli (Wells and Wellington, 1987)}- -{Pseudonaja affinis Günther, 1872}- -{Pseudonaja aspidorhyncha (McCoy, 1879)}- -{Pseudonaja guttata (Parker, 1926)}- -{Pseudonaja inframacula (Waite, 1925)}- -{Pseudonaja ingrami (Boulenger, 1908)}- -{Pseudonaja mengdeni Wells and Wellington, 1985}- -{Pseudonaja modesta (Günther, 1872)}- -{Pseudonaja nuchalis Günther, 1858}- -{Pseudonaja textilis (A. M. C. Duméril, Bibron and A. H. A. Duméril, 1854)}- -{Rhinoplocephalus bicolor F. Müller, 1885}- -{Salomonelaps par (Boulenger, 1884)}- -{Simoselaps anomalus (Sternfeld, 1919)}- -{Simoselaps bertholdi (Jan, 1859)}- -{Simoselaps bimaculatus (A. M. C. Duméril, Bibron and A. H. A. Duméril, 1854)}- -{Simoselaps littoralis (Storr, 1968)}- -{Simoselaps minimus (Worrell, 1960)}- -{Suta fasciata (Rosén, 1905)}- -{Suta ordensis (Storr, 1984)}- -{Suta punctata (Boulenger, 1896)}- -{Suta suta (W. C. H. Peters, 1863)}- -{Thalassophis anomalus P. Schmidt, 1852}- -{Toxicocalamus buergersi (Sternfeld, 1913)}- -{Toxicocalamus ernstmayri O'Shea, Parker and Kaiser, 2015}- -{Toxicocalamus grandis (Boulenger, 1914)}- -{Toxicocalamus holopelturus McDowell, 1969}- -{Toxicocalamus longissimus Boulenger, 1896}- -{Toxicocalamus loriae (Boulenger, 1898)}- -{Toxicocalamus mintoni Kraus, 2009}- -{Toxicocalamus misimae McDowell, 1969}- -{Toxicocalamus pachysomus Kraus, 2009}- -{Toxicocalamus preussi (Sternfeld, 1913)}- -{Toxicocalamus spilolepidotus McDowell, 1969}- -{Toxicocalamus stanleyanus Boulenger, 1903}- -{Tropidechis carinatus (Krefft, 1863)}- -{Vermicella annulata (Gray in Gray, 1841)}- -{Vermicella intermedia Keogh and S. A. Smith, 1996}- -{Vermicella multifasciata (Longman, 1915)}- -{Vermicella snelli Storr, 1968}- -{Vermicella vermiformis Keogh and S. A. Smith, 1996}-

Podvrste -{Acanthophis antarcticus antarcticus (Shaw and Nodder, 1802)}- -{Acanthophis antarcticus schistos Wells and Wellington, 1985}- -{Acanthophis wellsi donnellani Hoser, 2002}- -{Acanthophis wellsi wellsi Hoser, 1998}- -{Aspidomorphus muelleri interruptus Brongersma, 1934}- -{Aspidomorphus muelleri lineatus Brongersma, 1934}- -{Aspidomorphus muelleri muelleri (Schlegel, 1837)}- -{Brachyurophis fasciolatus fasciatus (Stirling and Zietz, 1893)}- -{Brachyurophis fasciolatus fasciolatus (Günther, 1872)}- -{Brachyurophis semifasciatus semifasciatus Günther, 1863}- -{Brachyurophis semifasciatus woodjonesii (Thomson, 1934)}- -{Demansia papuensis melaena Storr, 1978}- -{Demansia papuensis papuensis (Macleay, 1877)}- -{Demansia psammophis cupreiceps Storr, 1978}- -{Demansia psammophis psammophis (Schlegel, 1837)}- -{Hydrophis caerulescens caerulescens (Shaw, 1802)}- -{Hydrophis caerulescens hybridus Schlegel, 1844}-