O
Oaxaca Cichlid See Vieja zonata
Oaxaca Killifish See Profundulus punctatus
Oaxaca Livebearer See Poeciliopsis lutzi
Oaxacan Blue-Eye See Priapella intermedia
Obbes' Catfish See Porochilus obbesi
Obese Synodontis See Synodontis obesus
Oblique Band Cichlid See Aequidens plagiozonatus
Oblique Barred Panchax See Epiplatys spilargyreius
Oblong Cichlid See Nandopsis oblongum
Occidentarius platypogon (Günther 1864)
Ocean Pout See Zoarces americanus
Ocean Sunfish See Mola mola
Oceanic Puffer See Lagocephalus lagocephalus lagocephalus
Ocellated Dwarf Rasbora See Boraras urophthalmoides
Ocellated Freshwater Stingray See Potamotrygon motoro
Ocellated Killie See Aphyosemion ocellatum
Ocellated Killie See Aphyosemion ocellatum Bolapessa
Ocellated Killie See Aphyosemion ocellatum Gabon G 80/6
Ocellated Killie See Aphyosemion ocellatum Gabon PEG 93/9
Ocellated Killie See Aphyosemion ocellatum Gabon PEG 96/22
Ocellated Killie See Aphyosemion ocellatum Zenzele
Ocellated Killifish See Floridichthys polyommus
Ocellated Krib See Pelvicachromis subocellatus
Ocellated Labyrinth Fish See Ctenopoma muriei
Ocellated Loach See Acanthocobitis urophthalmus
Ocellated Micromolly See Poecilia branneri
Ocellated Pufferfish See Tetraodon cutcutia
Ocellated Rivulus See Kryptolebias ocellatus
Ocellated Shelldweller See Lamprologus ocellatus
Ocellated Shell-Dweller See Lamprologus kungweensis
Ocellated Spiny Eel See Mastacembelus vanderwaali
Ocellated Syndontis See Synodontis notata
Ochetobius elongatus (Kner 1867)
Ochmacanthus alternus (Myers 1927)
Ochmacanthus batrachostoma (Miranda-Ribeiro 1912)
Ochmacanthus flabelliferus (Eigenmann 1912)
Ochmacanthus orinoco (Myers 1927)
Ochmacanthus reinhardti See Ochmacanthus reinhardtii
Ochmacanthus reinhardtii (Steindachner 1882)
Ocmulgee Shiner See Cyprinella callisema
Octonema pleskei See Lefua costata
Octonematichthys laticeps See Clarotes laticeps
Octonematichthys nigrita See Clarotes laticeps
Odaxothrissa ansorgii (Boulenger 1910)
Odaxothrissa losera (Boulenger 1899)
Odaxothrissa mento (Regan 1917)
Odaxothrissa vittata (Regan 1917)
Odd-Finned Zacco See Zacco platypus
Odd-Lip Anostomus See Anostomus plicatus
Odd-Lip Hard-Head Catfish See Neoarius velutinus
Odd-Tail Eel Catfish See Gymnallabes typus
Odd-Tooth Perissodus See Plecodus paradoxus
Odessa Barb See Puntius sp Odessa Barb
Odondebuenia balearica (Pellegrin & Fage 1907)
Odontamblyopus rubicundus (Hamilton 1822)
Odonteleotris canina (Bleeker 1849)
Odonteleotris macrodon (Bleeker 1853)
Odonteleotris nesolepis See Allomogurnda nesolepis
Odontesthes argentinensis (Valenciennes 1835)
Odontesthes bonariensis (Valenciennes 1835)
Odontobutis obscura (Temminck & Schlegel 1845)
Odontobutis potamophila (Günther 1861)
Odontocharacidium aphanes (Weitzman & Kanazawa 1977)
Odontognathus mucronatus (Lacepède 1800)
Odontostibe piaba See Serrapinnus piaba
Odontostilbe caquetae See Odontostilbe fugitiva
Odontostilbe dialeptura (Fink & Weitzman 1974)
Odontostilbe dierythrura (Fowler 1940)
Odontostilbe drepanon See Odontostilbe fugitiva
Odontostilbe euspilurus See Lobodeuterodon euspilurus
Odontostilbe fugitiva (Cope 1870)
Odontostilbe gracilis (Géry 1960)
Odontostilbe hasemani See Odontostilbe dierythrura
Odontostilbe hastata See Saccoderma hastata
Odontostilbe iheringi See Serrapinnus heterodon
Odontostilbe kriegi See Serrapinnus kriegi
Odontostilbe littoris (Géry 1960)
Odontostilbe madeirae See Odontostilbe fugitiva
Odontostilbe microcephala (Eigenmann 1907)
Odontostilbe mitoptera (Fink & Weitzman 1974)
Odontostilbe mitopterus See Odontostilbe mitoptera
Odontostilbe paraguayensis (Eigenmann & Kennedy 1903)
Odontostilbe pequira (Steindachner 1882)
Odontostilbe pulchra (Gill 1858)
Odontostilbe roloffi (Gery 1972)
Odontostilbe stenodon (Eigenmann 1915)
Odontostilbe trementina See Odontostilbe pequira
Oedemognathus exodon (Myers 1936)
Oeser's Killie See Aphyosemion oeseri
Oesers Prachtkärpfling See Aphyosemion oeseri
Ogilbia pearsei (Hubbs 1938)
Ogilby's Rainbowfish See Melanotaenia ogilbyi
Ogowe Killie See Aphyosemion ogoense Bambama
Ogowe Killie See Aphyosemion ogoense Gabon
Ogowe Killie See Aphyosemion ogoense Kindamba
Ogowe Killie See Aphyosemion ogoense Lutete
Ogowe Killie See Aphyosemion ogoense Malinga
Ogowe Killie See Aphyosemion ogoense Mongouango
Ogowe-Prachtkärpfling See Aphyosemion ogoense
Ogowe-Prachtkärpfling Malinga See Aphyosemion ogoense
Ohio Lamprey See Ichthyomyzon bdellium
Ohrenbarsch See Acantharchus pomotis
Ohrid Gudgeon See Gobio ohridanus
Ohrid Trout See Salmo letnica
Oily bitterling See Tanakia limbata
Oiphthalmotilapia foae See Cyathopharynx furcifer
Okaloosa Darter See Etheostoma okaloosae
Okavango Robber See Rhabdalestes maunensis
Okavango Rock Catlet See Chiloglanis fasciatus
Okavango Suckermouth See Chiloglanis fasciatus
Okavango Tilapia See Tilapia ruweti
Okavango-kurper See Tilapia ruweti
Okavango-suierbekkie See Chiloglanis fasciatus
Okefenokee Dwarf Sunfish See Elassoma okefenokee
Okefenokee-Zwergsonnenbarsch See Elassoma okefenokee
Oktedi Rainbowfish See Melanotaenia oktediensis
Oktedi-Regenbogenfisch See Melanotaenia oktediensis
Olbrechts Hechtling See Epiplatys olbrechtsi olbrechtsi
Olbrechts Hechtling See Epiplatys olbrechtsi olbrechtsi CL 43
Olbrechts Hechtling See Epiplatys olbrechtsi olbrechtsi RL 52
Olbrechts Hechtling See Epiplatys olbrechtsi olbrechtsi RL 56
Olbrechts Hechtling See Epiplatys olbrechtsi olbrechtsi RL 79
Olbrechts Hechtling See Epiplatys olbrechtsi olbrechtsi RL 82
Olbrecht's Panchax See Epiplatys olbrechtsi olbrechtsi
Olbrecht's Panchax See Epiplatys olbrechtsi olbrechtsi CL 43
Olbrecht's Panchax See Epiplatys olbrechtsi olbrechtsi RL 52
Olbrecht's Panchax See Epiplatys olbrechtsi olbrechtsi RL 56
Olbrecht's Panchax See Epiplatys olbrechtsi olbrechtsi RL 79
Olbrecht's Panchax See Epiplatys olbrechtsi olbrechtsi RL 82
Olientodon multipunctatus See Skiffia multipunctata
Oligancistrus punctatissimus (Steindachner 1881)
Oligancistrus sp
Oligobrycon microstomus (Eigenmann 1915)
Oligocephalus grahami See Etheostoma grahami
Oligocephalus humeralis See Etheostoma flabellare
Oligocephalus leonensis See Etheostoma lepidum
Oligocephalus pulchellus See Etheostoma spectabile spectabile
Oligolepis acutipennis (Valenciennes 1837)
Oligolepis stomias (Smith 1941)
Oligoplites palometa (Cuvier 1832)
Oligosarcus argenteus (Günther 1864)
Oligosarcus bolivianus (Fowler 1940)
Oligosarcus hepsetus (Cuvier 1829)
Oligosarcus jenynsii (Günther 1864)
Oligosarcus macrolepis (Steindachner 1876)
Oligosarcus meadi See Oligosarcus argenteus
Oligosarcus pintoi (Amarai Campos 1945)
Oligosarcus planaltinae (Menezes & Géry 1983)
Oligosarcus robustus (Menezes 1969)
Oligosarcus sp
Olive Barb See Puntius sarana
Olive Darter See Percina squamata
Olive Flathead-Gudgeon See Butis amboinensis
Olive Labeo See Labeo greenii
Olive Lamprologus See Lamprologus olivaceus
Olive Limia See Limia versicolor
Olive Perchlet See Ambassis agassizii
Olive Perchlet See Ambassis nigripinnis
Olive Skiffia See Skiffia lermae
Olive Topminnow See Fundulus olivaceus
Olivegreen Ufipa Barb See Barbus olivaceus
Olive-Silver Catfish See Chrysichthys sianenna
Olivin-Barbensalmler See Curimata metae
Ollentodon multipunctatus See Skiffia multipunctata
Olmec Blind Catfish See Rhamdia macuspanensis
Olmecan Blue-Eye See Priapella olmecae
Olmeken-Kärpfling See Priapella olmecae
Oloplotosus luteus (Roberts 1978)
Oloplotosus mariae (Weber 1913)
Oloplotosus sp
Oloplotosus toboro See Oloplotosus torobo
Oloplotosus torobo (Allen 1985)
Olyfkurper See Serranochromis robustus robustus
Olympic Mudminnow See Novumbra hubbsi
Olyra burmanica (Day 1872)
Olyra horai (Prashad & Mukerji 1929)
Olyra kempi (Chaudhuri 1912)
Olyra laticeps See Amblyceps laticeps
Olyra longicaudata (McClelland 1842)
Olyrawels See Olyra longicaudata
Omegophora armilla (Waite & McCulloch 1915)
Omo Lampeye See Aplocheilichthys jeanneli
Omo Lampeye See Aplocheilichthys jeanneli
Omobranchus ferox (Herre 1927)
Ompok bimaculatus (Bloch 1794)
Ompok borneensis (Steindachner 1901)
Ompok canio (Hamilton 1822)
Ompok eugeneiatus (Vaillant 1893)
Ompok goae (Haig 1952)
Ompok hypophthalmus (Bleeker 1846)
Ompok javanensis (Hardenberg 1938)
Ompok leiacanthus (Bleeker 1853)
Ompok malabaricus (Valenciennes 1840)
Ompok miostoma (Vaillant 1902)
Ompok pabda (Hamilton 1822)
Ompok pabo (Hamilton 1822)
Ompok sabanus (Inger & Chin 1959)
Ompok sindensis (Day 1877)
Ompok weberi (Hardenberg 1936)
Onca See Liosomadoras oncinus
Oncorhynchus aguabonita (Jordan 1892)
Oncorhynchus apache (Miller 1972)
Oncorhynchus chrysogaster (Needham & Gard 1964)
Oncorhynchus clarki lewisi (Suckley 1874)
Oncorhynchus clarkii clarkii (Richardson 1836)
Oncorhynchus clarkii pleuriticus (Cope 1872)
Oncorhynchus gilae (Miller 1950)
Oncorhynchus gorbuscha (Walbaum 1792)
Oncorhynchus ishikawai (Jordan & McGregor 1925)
Oncorhynchus iwame (Kimura & Nakamura 1961)
Oncorhynchus keta (Walbaum 1792)
Oncorhynchus kisutch (Walbaum 1792)
Oncorhynchus masou formosanum See Oncorhynchus masou formosanus
Oncorhynchus masou formosanus (Jordan & Oshima 1919)
Oncorhynchus masou macrostomus (Jordan & McGregor 1925)
Oncorhynchus masou masou (Brevoort 1856)
Oncorhynchus masou rhodurus (Shaw 1796)
Oncorhynchus mykiss (Walbaum 1792)
Oncorhynchus nerka (Walbaum 1792)
Oncorhynchus rhodurus (Jordan & McGregor 1925)
Oncorhynchus tshawytscha (Walbaum 1792)
One Sided Livebearer See Jenynsia lineata
One Spot Molly See Poecilia vivipara
One Spot Mouthbrooder See Betta unimaculata Kampong Imam
One Spot Mouthbrooder See Betta unimaculata Tawau
One Stripe Jenynsia See Jenynsia unitaenia
One-And-A-Half-Stripe Hap See Protomelas insignis
One-Band Mosquitofish See Gambusia vittata
One-Banded African Tetra See Neolebias unifasciatus
One-Bar Panchax See Epiplatys singa
One-Line Hillstream Loach See Praeformosiana sp
Oneline Pencilfish See Nannostomus unifasciatus
One-Lined Pencil Fish See Nannostomus beckfordi
One-Lined Pencilfish See Nannostomus unifasciatus
Onespot Barb See Puntius terio
One-Spot Barb See Puntius terio
One-Spot Betta See Betta unimaculata
One-Spot Catfish See Mystus armatus
One-Spot Catfish See Synodontis notata
One-Spot Geophagus See Satanoperca lilith
One-Spot Glass Catfish See Ompok bimaculatus
One-Spot Headstander See Caenotropus labyrinthicus
One-Spot Hemiodus See Hemiodus parnaguae
One-Spot Hemiodus See Hemiodus unimaculatus
One-Spot Live-Bearer See Phalloceros caudimaculatus
One-Spot Live-Bearer See Poecilia vivipara
Onespot Squeaker See Synodontis notata
One-Stripe Hap See Haplochromis sp 6
One-Striped African Characin See Nannaethiops unitaeniatus
Onychodon debryyi See Hypophthalmichthys molitrix
Onychostoma alticorpus (Oshima 1920)
Onychostoma angustistomata (Fang 1940)
Onychostoma barbatulum (Pellegrin 1908)
Onychostoma barbatum (Lin 1931)
Onychostoma gerlachi (Peters 1881)
Onychostoma laticeps (Günther 1896)
Onychostoma lepturum (Boulenger 1900)
Onychostoma lini (Wu 1939)
Onychostoma ovale (Pellegrin & Chevey 1936)
Onychostoma rarum (Lin 1933)
Onychostoma sima See Onychostoma simum
Onychostoma simum (Sauvage & Dabry de Thiersant 1874)
Oos-Kaapse kurper See Sandelia bainsii
Oos-Kaapse rooivlerkie See Pseudobarbus afer
Ooskus-ghieliemientjie See Barbus toppini
Ooskus-longvis See Protopterus amphibius
Oostelike bottelneus See Mormyrops longirostris
Oostelike Happie See Astatotilapia calliptera
Oostethus brachyurus See Microphis brachyurus brachyurus
Oostethus brachyurus aculeatus See Microphis brachyurus aculeatus
Opal Allotoca See Allotoca dugesii
Opal Dwarf Cichlid See Apistogramma sp Opal
Opal Gourami See Trichogaster trichopterus Opal
Opal Pearlfish See Leptolebias opalescens
Opata Sucker See Catostomus wigginsi
Ophicephalus africanus See Parachanna africana
Ophicephalus argus See Channa argus argus
Ophicephalus asiatcus See Channa asiatica
Ophicephalus gachua See Channa gachua
Ophicephalus insignis See Parachanna insignis
Ophicephalus lucius See Channa lucius
Ophicephalus marulius See Channa marulius
Ophicephalus micropeltes See Channa micropeltes
Ophicephalus nigricans See Channa argus argus
Ophicephalus obscurus See Parachanna obscura
Ophicephalus pekinensis See Channa argus argus
Ophicephalus pleurophthalmus See Channa pleurophthalma
Ophicephalus punctatus See Channa punctata
Ophicephalus stenense See Channa micropeltes
Ophicephalus striatus See Channa striata
Ophichthus rutidoderma (Bleeker 1853)
Ophieleotris aporos (Bleeker 1854)
Ophiocara apores See Ophieleotris aporos
Ophiocara aporos See Ophieleotris aporos
Ophiocara macrolepidota (Bloch 1792)
Ophiocara ophiocephala See Ophiocara porocephala
Ophiocara porocephala (Valenciennes 1837)
Ophiocephalus africanus See Parachanna africana
Ophiocephalus argus See Channa argus argus
Ophiocephalus asiaticus See Channa asiatica
Ophiocephalus cyanospilus
Ophiocephalus gachua See Channa gachua
Ophiocephalus kelaatii See Channa gachua
Ophiocephalus lucius See Channa lucius
Ophiocephalus marulius See Channa marulius
Ophiocephalus maruloides
Ophiocephalus melanopterus
Ophiocephalus melanosoma See Channa melasoma
Ophiocephalus micropeltes See Channa micropeltes
Ophiocephalus obscurus See Parachanna insignis
Ophiocephalus obscurus See Parachanna obscura
Ophiocephalus pleurophthalmus See Channa pleurophthalma
Ophiocephalus polylepis
Ophiocephalus puncatus See Channa punctata
Ophiocephalus punctatus See Channa punctata
Ophiocephalus serpentinus See Channa micropeltes
Ophiocephalus striatus See Channa striata
Ophiocephalus vagus See Channa striata
Ophioicara porocephala See Ophiocara porocephala
Ophisternon aenigmaticum (Rosen & Greenwood 1976)
Ophisternon afrum (Boulenger 1909)
Ophisternon bengalense (McClelland 1844)
Ophisternon candidum (Mees 1962)
Ophisternon gutturale (Richardson 1845)
Ophisternon infernale (Hubbs 1938)
Ophisternon sp
Ophisternon sp 1
Ophisternon sp 2
Ophthalmochromis heterodontus See Ophthalmotilapia heterodonta
Ophthalmochromis nasutus See Ophthalmotilapia nasuta
Ophthalmochromis stappersi See Lestradea stappersii
Ophthalmochromis ventralis See Ophthalmotilapia heterodonta
Ophthalmochromis ventralis See Ophthalmotilapia ventralis
Ophthalmochromis ventralis heterodonta See Ophthalmotilapia heterodonta
Ophthalmochromis ventralis heterodontus See Ophthalmotilapia heterodonta
Ophthalmochromis ventralis ventralis See Ophthalmotilapia ventralis
Ophthalmolebias ilheusensis (Costa & Lima 2010)
Ophthalmotilapia boops (Boulenger 1901)
Ophthalmotilapia boops sp cf
Ophthalmotilapia foae See Cyathopharynx furcifer
Ophthalmotilapia heterodonta (Poll & Matthes 1962)
Ophthalmotilapia heterodontus See Ophthalmotilapia heterodonta
Ophthalmotilapia nasuta (Poll & Matthes 1962)
Ophthalmotilapia nasuta Tiger
Ophthalmotilapia nasutus See Ophthalmotilapia nasuta
Ophthalmotilapia stappersi See Lestradea stappersii
Ophthalmotilapia ventralis (Boulenger 1898)
Ophthalmotilapia ventralis heterodonta See Ophthalmotilapia heterodonta
Ophthalmotilapia ventralis heterodontus See Ophthalmotilapia heterodonta
Opisthanodus haerteli See Moenkhausia pittieri
Opisthonema oglinum (Lesueur 1818)
Opisthopterus effulgens (Regan 1903)
Opsaridium boweni (Fowler 1930)
Opsaridium christyi See Raiamas christyi
Opsaridium chrystyi See Raiamas christyi
Opsaridium engrauloides (Nichols 1923)
Opsaridium leleupi (Matthes 1965)
Opsaridium loveridgii (Norman 1922)
Opsaridium maculicauda (Pellegrin 1926)
Opsaridium microcephalum (Günther 1864)
Opsaridium microlepis (Günther 1864)
Opsaridium peringueyi (Gilchrist & Thompson 1913)
Opsaridium sp
Opsaridium ubangense See Opsaridium ubangiense
Opsaridium ubangiense (Pellegrin 1901)
Opsaridium zambezense (Peters 1852)
Opsariichthys barbatus See Candidia barbata
Opsariichthys bidens (Günther 1873)
Opsariichthys uncirostris (Temminck & Schlegel 1846)
Opsariichthys uncirostris amurensis (Berg 1932)
Opsarisium chrystyi See Raiamas christyi
Opsarius argyrotaenia See Rasbora argyrotaenia
Opsarius cocsa (Hamilton 1822)
Opsarius daniconius See Rasbora daniconius
Opsarius fasciatus See Barilius barna
Opsarius koratensis (Smith 1931)
Opsarius pulchellus (Smith 1931)
Opsarius thebensis See Leptocypris niloticus
Opsodoras boulengeri (Steindachner 1915)
Opsodoras boulengeri (Steindachner 1915)
Opsodoras hemipeltis (Eigenmann 1925)
Opsodoras humeralis (Kner 1855)
Opsodoras leporhinus (Eigenmann 1912)
Opsodoras morei (Steindachner 1881)
Opsodoras orthacanthus (Eigenmann 1925)
Opsodoras parallelus (Eigenmann 1925)
Opsodoras shibeli See Opsodoras stuebelii
Opsodoras sp
Opsodoras steindachneri (Eigenmann 1925)
Opsodoras stubeli See Opsodoras stuebelii
Opsodoras stuebelii (Steindachner 1882)
Opsodoras ternetzi (Eigenmann 1925)
Opsodoras trimaculatus (Boulenger 1898)
Opsopoeodus emiliae emiliae (Hay 1881)
Opsopoeodus emiliae peninsularis (Gilbert & Bailey 1972)
Opthalmotilapia boops cf See Ophthalmotilapia boops sp cf
Oragneflossen-Kärpfling See Priapichthys annectens
Orange Barb See Barbus fasciolatus
Orange Black-Spot See Hypostomus sp 7
Orange Bushfish See Ctenopoma ansorgii
Orange Bushfish Var. I See Ctenopoma ansorgii Var. I
Orange Bushfish Var. II See Ctenopoma ansorgii Var. II
Orange Chela See Chela dadiburjori
Orange Chromide See Etroplus maculatus
Orange Crenicichla See Crenicichla sp Xingu-Orange
Orange Dorsal Widow See Phallichthys amates
Orange Dwarf Killi See Aphyosemion fulgens
Orange False Barilius See Chela auropurpurens
Orange Fin Laetacara See Laetacara sp Orange Fin
Orange Finned Barb See Rasboroides vaterifloris
Orange Finned Danio See Danio kyathit
Orange Finned Flasher See Priapichthys annectens
Orange Finned Halfbeak See Dermogenys ebrardtii
Orange Finned Topminnow See Poeciliopsis monacha
Orange Fleck Uaru See Uaru sp
Orange Halfbeak See Nomorhamphus sp II
Orange Hap See Haplochromis benthicola
Orange Hatchetfish See Chela dadiburjori
Orange Knife Livebearer See Alfaro huberi
Orange Mbuna See Pseudotropheus sp Kingizei Lupingu
Orange Panchax See Epiplatys fasciolatus
Orange Peacock See Aulonocara sp Stuartgranti Maleri
Orange Point Tail See Pseudorinelepis sp
Orange Puffer See Tetraodon miurus
Orange River Mudfish See Labeo capensis
Orange Rocket See Alfaro huberi
Orange Seam Cat See Peckoltia sp orange-seam 1
Orange Spot Characin See Odontostilbe pequira
Orange Tailk Agasizii See Apistogramma agassizii Orange-Tail
Orange Throat Pleco See Hypostomus punctatus sp
Orange Tilapia See Tilapia sp Orange
Orange Yellow Peckoltia See Peckoltia sp 7
Orangeband-Kärpfling See Zoogoneticus sp. Crescent
Orangebelly Darter See Etheostoma radiosum
Orangeblauer Maulbrüter See Maylandia estherae
Orange-Breitband- Moorii See Tropheus moorii sp aff Bemba
Orange-Buschfisch See Ctenopoma ansorgii
Orange-Dorsal Live-Bearer See Phallichthys amates
Orange-Fin Acara See Laetacara thayeri
Orangefin Barb See Barbus eutaenia
Orangefin Darter See Etheostoma bellum
Orange-Fin Dwarf Cichlid See Apistogramma sp 8
Orangefin Labeo See Labeo calbasu
Orange-Fin Labeo See Labeo calbasu
Orangefin Madtom See Noturus gilberti
Orange-Fin Salmon Catfish See Arius sp
Orangefin Shiner See Notropis ammophilus
Orangefin Tetra See Bryconops affinis
Orange-finned Apistogramma See Apistogramma sp 3
Orange-Finned Hard-Head Catfish See Neoarius velutinus
Orange-finned Laetacara See Laetacara sp 2
Orange-Finned Loach See Yasuhikotakia modesta
Orangefleck-Bachschmerle See Schistura notostigma
Orangeflecken-Sonnenbarsch See Lepomis humilis
Orangefleck-Moorii Papageien-Moorii See Tropheus moorii Mpulungu
Orangeflecksalmler See Markiana nigripinnis
Orangeflossen Panzerwels See Corydoras sterbai
Orangeflossenkärpfling See Poeciliopsis monacha
Orangeflossen-Laetacara See Laetacara flavilabris
Orange-Fringed Killie See Fundulopanchax scheeli
Orange-Fringed Largemouth See Haplochromis brevis
Orange-fringed Terror See Aequidens sp Gold Saum
Orangehead Giant Gourami See Osphronemus goramy cf
Orangekehliger Springbarsch See Etheostoma spectabile spectabile
Orange-Lined Cichlid See Melanochromis joanjohnsonae
Orangener Halbschnäbler See Nomorhamphus sp II
Orangen-Hechtbuntbarsch See Crenicichla sp Xingu I
Orangepunkt-Salmler See Odontostilbe pequira
Orangerand-kurper See Haplochromis brevis
Orangerivier-moddervis See Labeo capensis
Orangeroter Tigerbuntbarsch See Cichlasoma festae
Orangeroter Zwergsalmler See Ladigesia roloffi
Orangesaum-Leuchtaugenfisch See Poropanchax hannerzi
Orangesaumwels See Baryancistrus sp
Orange-Seam Peckoltia See Peckoltia sp orange-seam
Orange-Spot Pleco See Ancistrus sp orange-spor
Orange-Spot Pleco See Scobiancistrus sp Orange spot
Orangespotted Sunfish See Lepomis humilis
Orange-Spotted Therapon See Mesopristes kneri
Orange-Spotted Toadfish See Torquigener hypselogeneion
Orangestriped Squeaker See Synodontis flavitaeniata
Orangetail Shiner See Pteronotropis merlini
Orange-Tailed Goodeid See Xenotoca eiseni
Orange-Tailed Killie See Pronothobranchius kiyawensis
Orangethroat Darter See Etheostoma spectabile spectabile
Orange-Throated Panchax See Epiplatys dageti dageti
Orange-Trim Sucker Catfish See Pseudacanthicus leopardus
Orange-Whiskered Catfish See Oloplotosus luteus
Orange-Xingu Crenicichla See Crenicichla sp Orange Xingu.Belem
Orange-Zwergprachtkärpfling See Aphyosemion fulgens
Oranjevlerk-ghieliemientjie See Barbus eutaenia
Orbi Chaetobranchopsis See Chaetobranchopsis orbicularis
Orchid Loach See Homaloptera orthogoniata
Orchid Nothobranch See Nothobranchius eggersi
Orchid Nothobranch See Nothobranchius eggersi TZ 97/4
Orchid Nothobranch See Nothobranchius eggersi TZ 97/55
Orchideen-Prachtgrundkärpfling See Nothobranchius eggersi
Orchideen-Prachtgrundkärpfling See Nothobranchius eggersi TZ 97/4
Orchideen-Prachtgrundkärpfling See Nothobranchius eggersi TZ 97/55
Ord River Mullet See Liza alata
Oregon Chub See Oregonichthys crameri
Oregonichthys crameri (Snyder 1908)
Oregonichthys kalawatseti (Markle, Pearsons & Bills 1991)
Oreias dabryi (Sauvage 1874)
Oreias toni See Barbatula barbatula
Oreichthys cosuatis (Hamilton 1822)
Oreichthys parvus See Oreichthys cosuatis
Oreochromis alcalica See Alcolapia alcalica
Oreochromis alcalicus See Alcolapia alcalica
Oreochromis alcalicus alcalicus See Alcolapia alcalica
Oreochromis alcalicus grahami See Alcolapia grahami
Oreochromis amphimelas (Hilgendorf 1905)
Oreochromis anderson See Oreochromis andersonii
Oreochromis andersoni See Oreochromis andersonii
Oreochromis andersonii (Castelnau 1861)
Oreochromis andersonni See Oreochromis andersonii
Oreochromis angolensis (Trewavas 1973)
Oreochromis anulerson See Oreochromis andersonii
Oreochromis athiensis See Oreochromis mossambicus
Oreochromis athiensis See Oreochromis spilurus niger
Oreochromis auraeus See Oreochromis aureus
Oreochromis aurea See Oreochromis aureus
Oreochromis aureus (Steindachner 1864)
Oreochromis cancellatus cancellatus See Oreochromis niloticus cancellatus
Oreochromis cancellatus filoa See Oreochromis niloticus filoa
Oreochromis chungruruensis (Ahl 1924)
Oreochromis danconai See Oreochromis spilurus spilurus
Oreochromis d'anconai See Oreochromis spilurus spilurus
Oreochromis esculentus (Graham 1928)
Oreochromis grahami See Alcolapia grahami
Oreochromis hornorum See Oreochromis urolepis hornorum
Oreochromis hunteri (Günther 1889)
Oreochromis ismailiaensis (Mekkawy 1995)
Oreochromis jipe (Lowe 1955)
Oreochromis karomo (Poll 1948)
Oreochromis karongae (Trewavas 1941)
Oreochromis korogwe (Lowe 1955)
Oreochromis latilabris See Alcolapia latilabris
Oreochromis lepidurus (Boulenger 1899)
Oreochromis leucostictus (Trewavas 1933)
Oreochromis leucostrictus See Oreochromis leucostictus
Oreochromis lidole (Trewavas 1941)
Oreochromis macrochir
Oreochromis macrochir macrochir (Boulenger 1912)
Oreochromis macrochir mweruensis See Oreochromis mweruensis
Oreochromis malagarasi (Trewavas 1983)
Oreochromis mariae See Tilapia mariae
Oreochromis melanotheron See Sarotherodon melanotheron melanotheron
Oreochromis microchir See Oreochromis macrochir
Oreochromis mortimeri (Trewavas 1966)
Oreochromis mossambica See Oreochromis mossambicus
Oreochromis mossambicus (Peters 1852)
Oreochromis mozambica See Oreochromis mossambicus
Oreochromis mweruensis (Trewavas 1983)
Oreochromis ndalalani See Alcolapia ndalalani
Oreochromis niger See Oreochromis spilurus niger
Oreochromis nilotica See Oreochromis niloticus niloticus
Oreochromis nilotica filoa See Oreochromis niloticus filoa
Oreochromis nilotics See Oreochromis niloticus niloticus
Oreochromis niloticus See Oreochromis niloticus niloticus
Oreochromis niloticus baringoensis (Trewavas 1983)
Oreochromis niloticus cancellatus (Nichols 1923)
Oreochromis niloticus eduardianus (Boulenger 1912)
Oreochromis niloticus edwardianus See Oreochromis niloticus eduardianus
Oreochromis niloticus filoa (Trewavas 1983)
Oreochromis niloticus lancellatus See Oreochromis niloticus cancellatus
Oreochromis niloticus niloticus (Linnaeus 1758)
Oreochromis niloticus sufutae See Oreochromis niloticus sugutae
Oreochromis niloticus sugutae (Trewavas 1983)
Oreochromis niloticus tana (Seyoum & Kornfield 1992)
Oreochromis niloticus vulcani (Trewavas 1933)
Oreochromis pangani See Oreochromis pangani pangani
Oreochromis pangani girigan (Lowe 1955)
Oreochromis pangani pangani (Lowe 1955)
Oreochromis placidus See Oreochromis placidus placidus
Oreochromis placidus placidus (Trewavas 1941)
Oreochromis placidus rovumae See Oreochromis placidus ruvumae
Oreochromis placidus ruvumae (Trewavas 1966)
Oreochromis rukwaensis (Hilgendorf & Pappenheim 1903)
Oreochromis saka (Lowe 1953)
Oreochromis salinicola (Poll 1948)
Oreochromis schwebischi (Sauvage 1884)
Oreochromis shiranus See Oreochromis shiranus shiranus
Oreochromis shiranus chilwae (Trewavas 1966)
Oreochromis shiranus shiranus (Boulenger 1897)
Oreochromis spilurus See Oreochromis spilurus spilurus
Oreochromis spilurus niger (Günther 1894)
Oreochromis spilurus percivali (Boulenger 1912)
Oreochromis spilurus spilurus (Günther 1894)
Oreochromis squamipinnis (Günther 1864)
Oreochromis tanganicae (Günther 1894)
Oreochromis upembae (Thys van den Audenaerde 1964)
Oreochromis upembae malagarasi See Oreochromis upembae
Oreochromis urolepis See Oreochromis urolepis urolepis
Oreochromis urolepis hornorum (Trewavas 1966)
Oreochromis urolepis urolepis (Norman 1922)
Oreochromis variabilis (Boulenger 1906)
Oreochromis vulcani See Oreochromis niloticus vulcani
Oreoglanis delacouri (Pellegrin 1936)
Oreoglanis macropterum (Vinciguerra 1890)
Oreoglanis siamensis (Smith 1933)
Oreoleuciscus handlirschi (Pietschmann 1933)
Oreoleuciscus humilis (Warpachowski 1889)
Oreoleuciscus pewzowi See Oreoleuciscus potanini
Oreoleuciscus potanini (Kessler 1879)
Oreonectes anophthalmus (Zheng 1981)
Oreonectes platycephalus (Günther 1868)
Oreonectes sp
Orestias See Orestias cuvieri
Orestias affinis See Orestias olivaceus
Orestias agassi See Orestias agassii owenii
Orestias agassi See Orestias agassii tschudii
Orestias agassii See Orestias agassii tschudii
Orestias agassii See Orestias agassizii
Orestias agassii agassii x Orestias agassii tschudii
Orestias agassii elegans
Orestias agassii owenii
Orestias agassii pequeni See Orestias frontosus
Orestias agassii tschudii
Orestias agassii uyunius
Orestias agassisii See Orestias agassizii
Orestias agassizi crequii See Orestias agassizii
Orestias agassizi inornata See Orestias agassizii
Orestias agassizi senechali See Orestias agassizii
Orestias agassizi typica See Orestias agassizii
Orestias agassizii (Valenciennes 1846)
Orestias agassizii ? See Orestias agassii owenii
Orestias agassizii ? See Orestias agassii tschudii
Orestias agassizii ? See Orestias jussiei
Orestias agassizii affinis See Orestias agassizii
Orestias agassizii elegans See Orestias agassii elegans
Orestias agassizii oweni See Orestias agassii owenii
Orestias agassizii pequeni See Orestias frontosus
Orestias agassizii tschudii See Orestias agassii tschudii
Orestias agassizii uyunius See Orestias agassii uyunius
Orestias albus (Valenciennes 1846)
Orestias albus ? See Orestias luteus
Orestias ascotanensis (Parenti 1984)
Orestias bairdi See Orestias pentlandii
Orestias bairdii See Orestias pentlandii
Orestias chungarensis (Vila & Pinto 1987)
Orestias crawfordi (Tchernavin 1944)
Orestias ctenolepis (Parenti 1984)
Orestias cuvieri (Valenciennes 1846)
Orestias cypho See Orestias luteus
Orestias elegans (Garman 1895)
Orestias elegans ? See Orestias agassii elegans
Orestias empyraeus See Orestias agassizii
Orestias farfani See Orestias luteus
Orestias forgeti (Lauzanne 1981)
Orestias frontosus (Cope 1876)
Orestias frontosus ? See Orestias agassii tschudii
Orestias gilsoni (Tchernavin 1944)
Orestias gracilis (Parenti 1984)
Orestias gymnotus (Parenti 1984)
Orestias hardini (Parenti 1984)
Orestias humboldti See Orestias cuvieri
Orestias imarpe (Parenti 1984)
Orestias incae (Garman 1895)
Orestias ispi (Lauzanne 1981)
Orestias jusiei puni
Orestias jussiaei See Orestias jussiei
Orestias jussiei (Valenciennes 1846)
Orestias jussiei ? See Orestias agassii owenii
Orestias jussiei jussiei See Orestias jussiei
Orestias jussiei puni See Orestias puni
Orestias langui See Orestias agassizii
Orestias lastarriae (Philippi 1876)
Orestias laucaensis (Arratia 1983)
Orestias lungui See Orestias agassizii
Orestias luteus (Valenciennes 1846)
Orestias luteus ? See Orestias mulleri
Orestias minimus (Tchernavin 1944)
Orestias minutus See Orestias minimus
Orestias mooni (Tchernavin 1944)
Orestias mulleri (Valenciennes 1846)
Orestias mulleri ? See Orestias agassii owenii
Orestias mulleri ? See Orestias albus
Orestias mulleri ? See Orestias luteus
Orestias multiporis (Parenti 1984)
Orestias mundus (Parenti 1984)
Orestias neuveui See Orestias albus
Orestias neveui See Orestias albus
Orestias olivaceus (Garman 1895)
Orestias ortoni See Orestias agassii tschudii
Orestias ortonii See Orestias agassii tschudii
Orestias oweni See Orestias agassii owenii
Orestias owenii See Orestias agassii owenii
Orestias owenii See Orestias agassii tschudii
Orestias parinacotensis (Arratia 1982)
Orestias pentlandi See Orestias cuvieri
Orestias pentlandi See Orestias pentlandii
Orestias pentlandii (Valenciennes 1846)
Orestias pentlandii fuscus See Orestias pentlandii
Orestias piacotensis (Vila 2006)
Orestias polonorum (Tchernavin 1944)
Orestias puni (Tchernavin 1944)
Orestias richersoni (Parenti 1984)
Orestias robustus (Parenti 1984)
Orestias rospigliosii See Orestias agassizii
Orestias rotundipinnis See Orestias luteus
Orestias silustani See Orestias olivaceus
Orestias taquiri (Tchernavin 1944)
Orestias tchernavini (Lauzanne 1981)
Orestias tirapatae See Orestias agassizii
Orestias tiripatae See Orestias agassizii
Orestias tomcooni (Parenti 1984)
Orestias tschudii See Orestias agassii tschudii
Orestias tutini (Tchernavin 1944)
Orestias txchudii ? See Orestias jussiei
Orestias uruni (Tchernavin 1944)
Orestias ututo (Parenti 1984)
Orestias uyunius See Orestias agassii uyunius
Orfe See Leuciscus idus
Orgichodes broussonnetii See Gobioides broussonnetii
Orient Killie See Aphanius mento
Oriental Chub See Leuciscus cephalus
Oriental Loach See Misgurnus anguillicaudatus
Oriental Weatherfish See Misgurnus anguillicaudatus
Orientkärpfling See Aphanius mento
Orinoco Biotodoma See Biotodoma wavrini cf
Orinoco Bujurquina See Bujurquina sp Orinoco
Orinoco Chaestostoma See Chaestostoma sp Venezuela
Orinoco Cichlasoma See Cichlasoma orinocense
Orinoco Crenicichla See Crenicichla orinoco
Orinoco Flag Cichlid See Mesonauta egregius sp aff
Orinoco Pike Cichlid See Cichla orinocensis
Orinoco Piranah See Pygocentrus cariba
Orinoco Sailfin Catfish See Pterygoplichthys multiradiatus
Orinoco Satanoperca See Satanoperca mapiritensis
Orinoco Spot-Finned Killie See Austrofundulus transilis transilis
Orinoco-Bachling See Rivulus deltaphilus
Orinocodoras eigenmanni (Myers 1927)
Orinoco-Schmerlenwels See Ochmacanthus orinoco
Ornamemtkamm-Pleco See Hypostomus sp 14
Ornament Cichlid See Nandopsis ornatus
Ornate Bagrid See Chrysichthys ornatus
Ornate Bichir See Polypterus ornatipinnis
Ornate Catfish See Chrysichthys ornatus
Ornate Cory See Corydoras ornatus
Ornate Ctenopoma See Ctenopoma ansorgii
Ornate Fin Syno See Synodontis ornatipinnis
Ornate Fin-Nipper See Ichthyborus ornatus
Ornate Goby See Istigobius ornatus
Ornate Gourami See Malpulutta kretseri
Ornate Gourami See Malpulutta kretseri minor
Ornate Halfbeak See Hemirhamphodon chrysopunctatus
Ornate Julie See Julidochromis ornatus
Ornate Limia See Limia ornata
Ornate Limia See Limia ornata cf
Ornate Pimelodus See Pimelodus ornatus
Ornate Rainbowfish See Rhadinocentrus ornatus
Ornate Rivulus See Rivulus ornatus
Ornate Sand Loach See Nemacheilus ornatus
Ornate Shiner See Codoma ornata
Ornate Tetra See Hyphessobrycon bentosi
Ornate Tetra See Hyphessobrycon rosaceus
Ornate Tiger Sand Loach See Schistura kohchangensis
Orrestias elegans See Orestias elegans
Orthochromis machadoi (Poll 1967)
Orthochromis machadoi ? See Orthochromis stormsi
Orthochromis machadoi cf See Orthochromis machadoi
Orthochromis malagaraziensis (David 1937)
Orthochromis polyacanthus (Boulenger 1899)
Orthochromis stormsi (Boulenger 1902)
Orthochromis torrenticola (Thys van den Audenaerde 1963)
Orthodon microlepidotus (Ayres 1854)
Orthosternarchus tamandua (Boulenger 1898)
Orthrias angorae angorae See Nemacheilus angorae
Orthrias brandti brandti See Barbatula brandtii
Orthrias brandtii See Nemacheilus oxianus
Orthrias brandtii See Barbatula brandtii
Orthrias insignis See Nemacheilus insignis
Orthrias oreas See Barbatula barbatula
Orthrias panthera See Barbatula panthera
Orthrias pindus (Economidis 1991)
Orthrias tigris See Barbatula tigris
Orthrias tschaiyssuensis See Barbatula tschaiyssuensis
Ortmann Dwarf Cichlid See Apistogramma ortmanni
Oryzias carnaticus (Jerdon 1849)
Oryzias celebensis (Weber 1894)
Oryzias curvinotus
Oryzias dancena (Hamilton 1822)
Oryzias javanicus (Bleeker 1854)
Oryzias javanicus Java
Oryzias javanicus Kuta
Oryzias latipes (Temminck & Schlegel 1846)
Oryzias latipes Gold
Oryzias latipes iliensis
Oryzias luzonensis (Herre & Ablan 1934)
Oryzias madagascariensis See Pantanodon madagascariensis
Oryzias marmoratus (Aurich 1935)
Oryzias matanensis (Aurich 1935)
Oryzias mekongensis (Uwa & Magtoon 1986)
Oryzias melastigma See Aplocheilus panchax
Oryzias melastigmus See Aplocheilus panchax
Oryzias melastigmus Calcutta
Oryzias melastigmus sp aff
Oryzias minutillus (Smith 1945)
Oryzias minutillus Banakok
Oryzias minutillus Satul
Oryzias nigrimas (Kottelat 1990)
Oryzias nigrimas Tentena
Oryzias orthognathus (Kottelat 1990)
Oryzias profundicola (Kottelat 1990)
Oryzias songkhramensis (Magtoon 2010)
Oryzias sp Bentota
Oryzias sp China
Oryzias timorensis (Weber & de Beaufort 1922)
Osbeck's Grenadier Anchovy See Coilia mystus
Oscar See Astronotus ocellatus
Oscar See Astronotus ocellatus Big-Spot
Osmerus eperlanus (Linnaeus 1758)
Osmerus mordax dentex (Steindachner & Kner 1870)
Osmerus mordax mordax (Mitchill 1814)
Osmerus spectrum (Cope 1870)
Osoog-tarpon See Megalops cyprinoides
Ospatulus palaemophagus (Herre 1924)
Ospatulus truncatulus (Herre 1924)
Osphromenus gorami See Osphronemus goramy
Osphromenus gorami cf See Osphronemus goramy cf
Osphromenus gorami Gold See Osphronemus goramy Gold
Osphromenus laticlavius See Osphronemus laticlavius
Osphromenus malayanus See Sphaerichthys osphromenoides
Osphromenus microlepis See Trichogaster microlepis
Osphromenus notatus See Sphaerichthys osphromenoides
Osphromenus saigonensis See Trichogaster trichopterus
Osphromenus septemfaxciatus See Osphronemus septemfasciatus
Osphromenus siamensis See Trichogaster trichopterus
Osphromenus striatus See Trichopsis vittata
Osphromenus trichopterus See Trichogaster leerii
Osphromenus trichopterus See Trichogaster trichopterus
Osphromenus trichopterus catoris See Trichogaster pectoralis
Osphromenus trichopterus koelreuteri See Trichogaster trichopterus
Osphromenus vittatus See Trichopsis vittata
Osphronemus deissneri See Parosphromenus deissneri
Osphronemus exodon (Roberts 1994)
Osphronemus gorami See Osphronemus goramy
Osphronemus goramy (Lacepède 1801)
Osphronemus goramy cf
Osphronemus goramy Gold
Osphronemus gourami See Osphronemus goramy
Osphronemus laticlavius (Roberts 1992)
Osphronemus notatus See Osphronemus goramy
Osphronemus olfas See Osphronemus goramy
Osphronemus olfax See Osphronemus goramy
Osphronemus satyrus See Osphronemus goramy
Osphronemus septemfasciatus (Roberts 1992)
Ossubtus xinguense (Jegu 1992)
Ostafrikanischer Leuchtaugenfisch See Micropanchax loati
Ostafrikanischer Quappenwels See Amphilius sp
Ostasiatischer Kiemenschlitzaal See Monopterus albus
Ostasiatischer Schlammpeitzger See Misgurnus anguillicaudatus
Osteobrama alfredianus (Valenciennes 1844)
Osteobrama bakeri (Day 1873)
Osteobrama belangeri (Valenciennes 1844)
Osteobrama cotio cotio (Hamilton 1822)
Osteobrama cotio cunma (Day 1888)
Osteobrama cotio peninsularis (Silas 1952)
Osteobrama dayi (Hora & Misra 1940)
Osteobrama feae (Vinciguerra 1890)
Osteobrama neilli (Day 1873)
Osteobrama vigorsii (Sykes 1839)
Osteocheilus vittatus See Osteochilus vittatus
Osteochilichthys brevidorsalis (Day 1873)
Osteochilus bellus (Popta 1904)
Osteochilus bleekeri (Kottelat 2008)
Osteochilus borneensis (Bleeker 1857)
Osteochilus brachynotopteroides (Chevey 1934)
Osteochilus brachynotopterus See Osteochilus microcephalus
Osteochilus brachynotopterus See Osteochilus vittatus
Osteochilus brevicauda See Osteochilus kappenii
Osteochilus brevidorsalis See Osteochilichthys brevidorsalis
Osteochilus chalybeatus See Labeo gonius
Osteochilus chini (Karnasuta 1993)
Osteochilus duostigma See Osteochilus vittatus
Osteochilus enneaporos (Bleeker 1852)
Osteochilus enneaporus See Osteochilus enneaporos
Osteochilus flavicauda (Kottelat & Tan 2009)
Osteochilus godavariensis (Babu Rao 1977)
Osteochilus harrisoni (Fowler 1905)
Osteochilus hasselti See Osteochilus hasseltii
Osteochilus hasselti tweediei See Osteochilus vittatus
Osteochilus hasseltii (Valenciennes 1842)
Osteochilus ingeri (Karnasuta 1993)
Osteochilus intermedius (Weber & de Beaufort 1916)
Osteochilus jentinki See Diplocheilichthys jentinkii
Osteochilus jentinkii See Diplocheilichthys jentinkii
Osteochilus jeruk (Hadiaty & Siebert 1998)
Osteochilus kahajanensis (Bleeker 1857)
Osteochilus kahajanensis chini See Osteochilus chini
Osteochilus kalabau See Osteochilus kelabau
Osteochilus kappenii (Bleeker 1857)
Osteochilus kelabau (Popta 1904)
Osteochilus kerinciensis (Tan & Kottelat 2009)
Osteochilus kuekenthali (Ahl 1922)
Osteochilus kuhlii See Osteochilus vittatus
Osteochilus lini (Fowler 1935)
Osteochilus longidorsalis (Pethiyagoda & Kottelat 1994)
Osteochilus macrosemion See Cirrhinus molitorella
Osteochilus malabaricus See Osteochilus nashii
Osteochilus malanopleurus See Osteochilus melanopleurus
Osteochilus melanopleura See Osteochilus melanopleurus
Osteochilus melanopleurus (Bleeker 1852)
Osteochilus microcephalus (Valenciennes 1842)
Osteochilus nashii (Day 1869)
Osteochilus neilli See Osteochilus vittatus
Osteochilus ochrus See Labeo erythropterus
Osteochilus oligolepis See Osteochilus spilurus
Osteochilus partilineatus (Kottelat 1995)
Osteochilus pentalineatus (Kottelat 1982)
Osteochilus pleurotaenia See Diplocheilichthys pleurotaenia
Osteochilus prosemion See Cirrhinus molitorella
Osteochilus repang (Popta 1904)
Osteochilus salsburi See Osteochilus salsburyi
Osteochilus salsburyi (Nichols & Pope 1927)
Osteochilus sarawakensis (Karnasuta 1993)
Osteochilus scapularis (Fowler 1939)
Osteochilus schlegeli See Osteochilus schlegelii
Osteochilus schlegelii (Bleeker 1851)
Osteochilus serokan (Hadiaty & Siebert 1998)
Osteochilus sondhii (Hora & Mukerji 1934)
Osteochilus soplaoensis See Osteochilus waandersii
Osteochilus sp
Osteochilus spilopleura See Cirrhinus molitorella
Osteochilus spilulus See Osteochilus spilurus
Osteochilus spilurus (Bleeker 1851)
Osteochilus striatus (Kottelat 1998)
Osteochilus tatumi See Bangana behri
Osteochilus thomassi (Day 1877)
Osteochilus tripore See Osteochilus microcephalus
Osteochilus triporos (Bleeker 1852)
Osteochilus triporus See Osteochilus triporos
Osteochilus vittatoides (Popta 1904)
Osteochilus vittatus (Valenciennes 1842)
Osteochilus waandersi See Osteochilus waandersii
Osteochilus waandersii (Bleeker 1852)
Osteogaster eques See Corydoras eques
Osteogeneiosus militaris (Linnaeus 1758)
Osteogeniosus militaris See Osteogeneiosus militaris
Osteoglossum bicirrhosum (Cuvier 1829)
Osteoglossum ferrarai See Osteoglossum ferreirai
Osteoglossum ferreirai (Kanazawa 1966)
Osteoglossum jardinii See Scleropages jardinii
Osteoglossum vandelli See Osteoglossum bicirrhosum
Ostfrikanischer Stromschnellenwels See Chiloglanis neumanni cf
Ostlicher Kaplabyrinthfisch See Sandelia bainsii
Osydoras dorbignyi See Pterodoras granulosus
Othonocheirodus eigenmanni (Myers 1927)
Othonocheirodus lethostigmus (Gomes 1947)
Otjikoto Tilapia See Tilapia guinasana
Otjikoto-kurper See Tilapia guinasana
Otocinclus affinis See Macrotocinclus affinis
Otocinclus affinis cf
Otocinclus arnoldi See Otocinclus flexilis
Otocinclus batmani (Lehmann A. 2006)
Otocinclus bororo (Schaefer 1997)
Otocinclus caxarari (Schaefer 1997)
Otocinclus cephalacanthus See Otothyris lophophanes
Otocinclus cocama (Reis 2004)
Otocinclus depressicauda See Hisonotus depressicauda
Otocinclus fimbriatus See Otocinclus flexilis
Otocinclus flexilis (Cope 1894)
Otocinclus francirochai See Hisonotus francirochai
Otocinclus gibbosus See Lampiella gibbosa
Otocinclus hasemani (Steindachner 1915)
Otocinclus hoppei (Miranda-Ribeiro 1939)
Otocinclus huaorani (Schaefer 1997)
Otocinclus joberti See Hypoptopoma joberti
Otocinclus laevior See Hisonotus laevior
Otocinclus leucofrenatus See Hisonotus leucofrenatus
Otocinclus lophophanes See Otothyris lophophanes
Otocinclus macrospilus (Eigenmann & Allen 1942)
Otocinclus macrospilus ? See Otocinclus vittatus
Otocinclus maculicauda See Hisonotus notatus
Otocinclus maculicauda See Parotocinclus maculicauda
Otocinclus maculipinnis See Hisonotus maculipinnis
Otocinclus mariae (Fowler 1940)
Otocinclus mariae ? See Otocinclus vittatus
Otocinclus mariae cf
Otocinclus mimulus (Axenrot & Kullander 2003)
Otocinclus mura (Schaefer 1997)
Otocinclus nattereri
Otocinclus negros
Otocinclus nigricauda See Hisonotus nigricauda
Otocinclus notatus See Hisonotus notatus
Otocinclus notatus cf See Hisonotus notatus cf
Otocinclus obtusus See Pseudotothyris obtusa
Otocinclus paulinus See Hisonotus paulinus
Otocinclus sp
Otocinclus sp 1
Otocinclus sp 2
Otocinclus sp Tiger
Otocinclus spectabilis See Nannoptopoma spectabile
Otocinclus tapirape (Britto & Moreira 2002)
Otocinclus tietensis (Ihering 1907)
Otocinclus vestitus (Cope 1872)
Otocinclus vittatus (Regan 1904)
Otocinclus xakriaba (Schaefer 1997)
Otolithoides pama (Hamilton 1822)
Otopharynx argyrosoma (Regan 1922)
Otopharynx auromarginatus (Boulenger 1908)
Otopharynx brooksi (Oliver 1989)
Otopharynx chrysogaster See Naevochromis chrysogaster
Otopharynx decorus (Trewavas 1935)
Otopharynx heterodon (Trewavas 1935)
Otopharynx intermedius See Ctenopharynx intermedius
Otopharynx lithobates (Oliver 1989)
Otopharynx 'Mpombo' See Otopharynx sp Heterodon Longnose
Otopharynx nitidus See Ctenopharynx nitidus
Otopharynx ovatus (Trewavas 1935)
Otopharynx pictus See Ctenopharynx pictus
Otopharynx selenurus (Regan 1922)
Otopharynx sp Auromarginatus Goldhead
Otopharynx sp Auromarginatus Jakuta
Otopharynx sp Auromarginatus Jakuta Eastern
Otopharynx sp Auromarginatus Margrette
Otopharynx sp Automartinatus Mara
Otopharynx sp Big Spot Tanzania
Otopharynx sp Blue Otter
Otopharynx sp Blue Yellow Tanzania
Otopharynx sp Cave
Otopharynx sp Golden Blueface
Otopharynx sp Heterodon Likoma
Otopharynx sp Heterodon Longnose
Otopharynx sp Heterodon Nankhumba
Otopharynx sp Longnose Tanznia See Otopharynx sp Heterodon Longnose
Otopharynx sp Royal Blue
Otopharynx sp Royal Tanzania See Otopharynx heterodon
Otopharynx sp Spot
Otopharynx speciosus (Trewavas 1935)
Otopharynx tetraspilus (Trewavas 1935)
Otopharynx tetrastigma (Günther 1894)
Otopharynx walteri (Konings 1990)
Otopharynx 'Yellow Fin Mloto' See Otopharynx tetrastigma
Otothyris canaliferus See Otothyris lophophanes
Otothyris lophophanes (Eigenmann & Eigenmann 1889)
Otothyris sp
Ouachita madtom See Noturus lachneri
Ouachita Shiner See Lythrurus snelsoni
Ouwen's Goby See Sicyopterus ouwensi
Oviedo Pupfish See Cyprinodon nichollsi
Oviparous Halfbeak See Hemirhamphodon tengah
Owens Pupfish See Cyprinodon radiosus
Owens Sucker See Catostomus fumeiventris
Owens Wüstenfisch See Cyprinodon radiosus
Oxeye Herring See Megalops cyprinoides
Oxeye Tarpon See Megalops cyprinoides
Oxleyan Pygmy Perch See Nannoperca ozleyana
Oxuderces wirzi (Koumans 1937)
Oxybrycon parvulus (Géry 1964)
Oxydoras kneri (Bleeker 1862)
Oxydoras niger (Valenciennes 1821)
Oxydoras sifontesi (Fernández-Yépez 1968)
Oxydoras steindachneri (Perugia 1897)
Oxydoras stubeli See Opsodoras stuebelii
Oxyeleotris altipinna (Allen & Renyaan 1996)
Oxyeleotris aruensis (Weber 1911)
Oxyeleotris caeca (Allen 1996)
Oxyeleotris fimbriata (Weber 1907)
Oxyeleotris fimbriatus See Oxyeleotris fimbriata
Oxyeleotris gyrinoides (Bleeker 1853)
Oxyeleotris herwerdeni See Oxyeleotris herwerdenii
Oxyeleotris herwerdenii (Weber 1910)
Oxyeleotris herwerdinii See Oxyeleotris herwerdenii
Oxyeleotris heterodon (Weber 1907)
Oxyeleotris lineolata See Oxyeleotris lineolatus
Oxyeleotris lineolatus (Steindachner 1867)
Oxyeleotris marmorata (Bleeker 1852)
Oxyeleotris marmoratus See Oxyeleotris marmorata
Oxyeleotris nullipora (Roberts 1978)
Oxyeleotris paucipora (Roberts 1978)
Oxyeleotris selheimi (Macleay 1884)
Oxyeleotris siamensis (Günther 1861)
Oxyeleotris siamensis ? See Oxyeleotris urophthalmus
Oxyeleotris sp
Oxyeleotris sp 1
Oxyeleotris sp A (Rendahl 1922)
Oxyeleotris urophthalmoides (Bleeker 1853)
Oxyeleotris urophthalmus (Bleeker 1851)
Oxyeleotris wisselensis (Allen & Boeseman 1982)
Oxygaster anomalura (Van Hasselt 1823)
Oxygaster atpar See Chela cachius
Oxygaster bacaila See Salmophasia bacaila
Oxygaster oxygastroides See Parachela oxygastroides
Oxygaster pointoni (Fowler 1934)
Oxyglanis sacchii See Auchenoglanis occidentalis
Oxylapia polli (Kiener & Maugé 1966)
Oxyleotris marmoratus See Oxyeleotris marmorata
Oxyloricaria barbata See Sturisoma barbatum
Oxyloricaria leightoni See Sturisomatichthys leightoni
Oxyloricaria panamensis See Sturisoma panamense
Oxymormyrus boulengeri (Pellegrin 1900)
Oxymormyrus zanclirostris (Günther 1867)
Oxynoemacheilus brandtii See Barbatula brandtii
Oxynoemacheilus bureschi (Drensky 1928)
Oxynoemacheilus merga (Krynicki 1840)
Oxyporhamphus convexus (Weber & De Beaufort 1922)
Oxyporhamphus micropterus micropterus (Valenciennes in Cuvier & Valenciennes 1847)
Oxyrhunchus anfuilloides See Mormyrops anguilloides
Oxyrhunchus Cichlid See Hemitilapia oxyrhyncha
Oxyrhynchus custus See Mormyrops curtus
Oxyropsis carinata (Steindachner 1879)
Oxyropsis wrightiana (Eigenmann & Eigenmann 1889)
Oxysschmerle See Nemacheilus oxianus
Oxyzgonectes balboae See Fundulus olivaceus
Oxyzygonectes dovii (Günther 1866)
Oxyzygonectes dowi See Oxyzygonectes dovii
Oyapock Ancistrus See Ancistrus sp Oyapick
Oyapock Krobia See Krobia sp Oyapock
Oyapock Loricaria See Cteniloricaria fowleri
Oyster Goby See Arenigobius leftwichi
Ozark Bass See Ambloplites constellatus
Ozark Cavefish See Amblyopsis rosae
Ozark Chub See Erimystax harryi
Ozark Logperch See Percina fulvitaenia
Ozark Madtom See Noturus albater
Ozark Minnow See Dionda nubila
Ozark Minnow See Notropis nubilus
Ozark Sculpin See Cottus hypselurus
Ozark Shiner See Notropis ozarcanus
Ozolabäbling See Barilius barna