Skip to content
— CH. 1 · INTRODUCTION —

Fish

~7 min read · Ch. 1 of 8
8 sections

  • There are over 33,000 living species of fish, easily the largest group of vertebrates on Earth. That is more than all the amphibians, reptiles, birds, and mammals combined. A fish is an aquatic, gill-bearing vertebrate with a tough cranium guarding the brain, but no limbs ending in digits. The study of these animals has its own name: ichthyology. Yet the word itself hides a small mystery. The plural is fish when you mean many individuals, and fishes when you mean many species. So what, exactly, holds this vast group together, and what pulls it apart? Some of these creatures glow with their own electricity. Some breathe air. Some recognize themselves in a mirror. A few have all but left the water behind. And one quiet fact unsettles the whole category: by the rules of modern biology, you may be a kind of fish yourself.

  • Fishes of the World makes a startling admission, that "it is increasingly widely accepted that tetrapods, including ourselves, are simply modified bony fishes." That sentence dissolves a boundary most people take for granted. Modern phylogenetics treats fish as a paraphyletic group, meaning it includes nearly all vertebrates except the tetrapods, the four-limbed animals that came later. Any clade broad enough to hold all jawed fish or all bony fish also sweeps in the tetrapods. For this reason the old class Pisces, found in older reference works, has been dropped from formal classification. The relationships sort into the basal jawless fish and the more familiar jawed fish. The jawed branch covers the living cartilaginous and bony fish, plus two extinct lines, the placoderms and the acanthodians. Convergence muddies the picture further. Cetaceans and ichthyosaurs are tetrapods that secondarily took on a fish-like body shape, so a streamlined swimmer is not always what it seems.

  • About 530 million years ago, during the Cambrian explosion, fishlike animals with a notochord and forward-facing eyes appear in the fossil record, among them Haikouichthys. The earliest fish were small filter feeders. The ostracoderms, the first fish with dedicated respiratory gills and paired fins, carried heavy bony plates as exoskeletons against invertebrate predators. Jaws changed the contest. The placoderms, the first jawed fish, appeared in the Silurian, giant armoured hunters like Dunkleosteus among them. The Silurian also produced the cartilaginous Chondrichthyes and the bony Osteichthyes. During the Devonian, fish diversity surged so dramatically that the period earned the epithet "the age of fishes." Bony fish carried swim bladders and, in time, ossified endoskeletons. They rose to dominance after the end-Devonian extinction wiped out the placoderms, the reigning apex predators. From the lobe-finned branch, during the Carboniferous, came the tetrapods, developing air-breathing lungs homologous to swim bladders. The very organ that lets a fish float is, in another body, the lung that let life walk ashore.

  • The whale shark stretches to 16 metres, while some tiny teleosts measure only 8 millimetres, including the cyprinid Paedocypris progenetica and the stout infantfish. Teleosts dominate by sheer number; these ray-finned fish able to protrude their jaws make up 96% of all fish species. Roughly half of all living vertebrates belong to the class Actinopterygii, the ray-finned fishes. As of 2016, scientists had described over 32,000 species of bony fish, over 1,100 cartilaginous fish, and over 100 hagfish and lampreys. A third of all fish fall within just nine families, led by the Cyprinidae, the Gobiidae, and the Cichlidae. About 64 families are monotypic, holding a single species each. Speed spans an equally wide range. Tuna, salmon, and jacks cover 10 to 20 body-lengths per second, while eels and rays manage no more than half a body-length in the same time. The typical fish is cold-blooded and streamlined, but each rule has exceptions. Some fast swimmers are warm-blooded, and some slow swimmers abandoned streamlining for stranger shapes.

  • At the bottom of the Puerto Rico Trench, 8,370 metres down, a cusk-eel named Abyssobrotula galatheae holds the record as the deepest fish ever found in the ocean. Fish are split roughly evenly between habitats, some 15,200 freshwater species and around 14,800 marine. The center of marine diversity sits in the coral reefs of the Indo-Pacific, while freshwater fish crowd the great tropical river basins of the Amazon, Congo, and Mekong. More than 5,600 fish species live in Neotropical freshwaters alone, about 10% of all vertebrate species on Earth. The temperature extremes are punishing. Jonah's icefish live under the Filchner-Ronne Ice Shelf at a latitude of 79 degrees south, while desert pupfish endure springs as hot as 36 degrees Celsius. A few have nearly forsaken water entirely. Mudskippers feed and quarrel on mudflats, retreating underwater to hide in burrows. A single undescribed species of Phreatobius, a worm-like catfish, has been called a true "land fish," living strictly among waterlogged leaf litter. No fish, however, has been found in the deepest 25% of the ocean.

  • The fish heart pumps blood in a single loop, a simpler arrangement than the mammal heart with its two. Blood goes from heart to gills, picks up oxygen, then flows on to the body tissues without a second push. The gills themselves are masterworks of efficiency. Comblike filaments hold capillary networks, and the blood inside flows opposite to the incoming water, a countercurrent exchange that strips oxygen from every drop. Sharks usually carry five gill openings, sometimes six or seven, and many must keep swimming to breathe. Bony fish hide a single opening on each side beneath a bony cover, the operculum. Some 400 species across 50 families can breathe air, escaping oxygen-poor water or crawling onto land. Bichirs and lungfish carry tetrapod-like paired lungs and must surface to gulp, making them obligate air breathers. Excretion follows the water. Saltwater fish lose water by osmosis and produce concentrated urine, while freshwater fish gain it and produce a dilute one. Most release their nitrogenous waste as ammonia, and salt leaves through the rectal gland.

  • Manta rays and wrasses placed before a mirror repeatedly check whether the reflection mimics their own movements, a sign of self-awareness. The Choerodon wrasse, the archerfish, and the Atlantic cod can solve problems and invent tools. The monogamous cichlid Amatitlania siquia turns pessimistic when kept from its partner, and behavioral research suggests fish are sentient and capable of feeling pain. Their sensory world runs far beyond ours. The lateral line, a network of skin sensors, reads gentle currents and the motion of nearby fish, and blind cave fish navigate almost entirely by it. Catfish and sharks carry the ampullae of Lorenzini, electroreceptors tuned to currents on the order of a millivolt. Many fish see in color with three cone types, and some cyprinids add a fourth cone for ultraviolet. Salmon and others possess magnetoreception, reorienting when a magnetic field shifts around their tank, by a mechanism still unknown. Brains vary too. A typical fish brain is one-fifteenth the mass of a bird or mammal of similar size, yet the mormyrids and sharks rival birds and marsupials. Some fish go further, turning muscle into a weapon. The electric eel can generate shocks powerful enough to stun its prey.

  • The French grunt, Haemulon flavolineatum, grinds its teeth to produce a grunt near 700 hertz lasting about 47 milliseconds, especially when in distress. Communication by sound runs through courtship, feeding, and aggression. The oyster toadfish contracts sonic muscles along its swim bladder to make loud grunts and longer "boat whistle calls" that draw mates, ranging from 140 to 260 hertz. The red drum, Sciaenops ocellatus, drums by vibrating its swim bladder, though females stay silent, lacking sonic muscles entirely. Humans have leaned on fish since prehistoric times. Fish farming has been practiced in ancient China since about 3,500 BCE, and by 2007 roughly one-sixth of the world's protein came from fish. The relationship has also turned destructive. The Pacific sardine fishery off California fell from a 1937 peak of 800,000 tonnes to an unviable 24,000 tonnes by 1968, and overfishing cut the Atlantic northwest cod population to 1% of its historical level by 1992. Through all of it, fish stayed sacred. Early Christians used the ichthys to represent Jesus, the Hindu god Matsya took a fish form, and the constellation Pisces traces to a Roman legend in which two fishes rescued Venus and her son Cupid.

Up Next

Reptile

Continue Browsing

Paraphyletic groups

Common questions

What is a fish in biology?

A fish is an aquatic, anamniotic, gill-bearing vertebrate with a tough cranium protecting the brain but lacking limbs with digits. Fish divide into the basal jawless fish and the more common jawed fish, which include living cartilaginous and bony fish plus the extinct placoderms and acanthodians. The study of fish is called ichthyology.

How many species of fish are there?

There are over 33,000 extant species of fish, easily the largest group of vertebrates and more numerous than all amphibians, reptiles, birds, and mammals combined. As of 2016 there were over 32,000 described bony fish, over 1,100 cartilaginous fish, and over 100 hagfish and lampreys. Teleosts make up 96% of all fish species.

Why are fish considered a paraphyletic group?

Fish are paraphyletic because any clade containing all jawed fish or all bony fish also contains the tetrapods, the four-limbed vertebrates usually not counted as fish. For this reason the old class Pisces is no longer used in formal classification. Fishes of the World notes that tetrapods, including humans, are simply modified bony fishes.

What was the Devonian age of fishes?

The Devonian is called the age of fishes because fish diversity greatly increased during it, including among placoderms, lobe-finned fishes, and early sharks. The first jawed fish, the placoderms, appeared in the Silurian and diversified enormously in the Devonian. Bony fish became dominant after the end-Devonian extinction wiped out the placoderms.

What is the deepest living fish ever found?

The deepest fish found in the ocean is a cusk-eel, Abyssobrotula galatheae, recorded at the bottom of the Puerto Rico Trench at 8,370 metres. Fish inhabit nearly all aquatic environments, though none have been found in the deepest 25% of the ocean.

Are fish intelligent and can they feel pain?

Fish show cognitive capacities including self-awareness in mirror tests, demonstrated by manta rays and wrasses checking their reflections. Choerodon wrasse, archerfish, and Atlantic cod can solve problems and invent tools, and fish can learn to traverse mazes using spatial memory. Behavioral research suggests fish are sentient and capable of experiencing pain.

How has overfishing affected fish populations?

Overfishing reduced the Atlantic northwest cod population to 1% of its historical level by 1992, and the Pacific sardine fishery off California fell from a 1937 peak of 800,000 tonnes to 24,000 tonnes by 1968. The Food and Agriculture Organization reported that in 2017-34 percent of the world's marine fish stocks were classified as overfished.

What role do fish play in religion and culture?

Fish carry symbolic significance across many religions, with fish offerings made to the gods in ancient Mesopotamia and fish serving as a major symbol of Enki, the god of water. Early Christians used the ichthys to represent Jesus, the Hindu deity Matsya took fish form, and the constellation Pisces traces to a Roman legend about two fishes rescuing Venus and Cupid.

See all questions about Fish →

All sources

135 references cited across the entry

  1. 1webDWDS – Digitales Wörterbuch der deutschen Sprache
  2. 2bookA Gothic etymological dictionaryWinfred Philipp Lehmann et al. — BRILL — 1986
  3. 3webfish, n.1Oxford University Press
  4. 4bookA Dictionary of Selected Synonyms in the Principal Indo-European LanguagesCarl Darling Buck — University of Chicago Press — 1949
  5. 5encyclopediaFish(es)Daniel Pauly — Cambridge University Press — 13 May 2004
  6. 6bookThe Fishes of AlbertaJoseph S. Nelson et al. — University of Alberta — 1992
  7. 7journalHead and backbone of the Early Cambrian vertebrate HaikouichthysD. G. Shu et al. — 2003
  8. 8journalThe Evolutionary Emergence of Vertebrates From Among Their Spineless RelativesPhilip C. J. Donoghue et al. — 2009
  9. 9journalCambrian and earliest Ordovician conodont evolution, biofacies, and provincialismJames F. Miller et al. — 1984
  10. 10newsMonster fish crushed opposition with strongest bite ever30 November 2006
  11. 11journalThe largest Silurian vertebrate and its palaeoecological implicationsBrian Choo et al. — 2014
  12. 12journalSpiny chondrichthyan from the lower Silurian of South ChinaPlamen S. Andreev et al. — September 2022
  13. 13journalThe oldest gnathostome teethPlamen S. Andreev et al. — September 2022
  14. 14bookBiologyLinda R. Berg et al. — Cengage Learning — 2004
  15. 15journalHooked on fossilsRex Dalton — January 2006
  16. 16journalWe are primates and we are fish: Teaching monophyletic organismal biologyHarry W. Greene — 1998-01-01
  17. 17bookMarine Mammals: Adaptations for an Aquatic LifeR. W. Davis — Springer International Publishing — 2019
  18. 18journalFive hundred million years of extinction and recovery: A Phanerozoic survey of large-scale diversity patterns in fishesMatt Friedman et al. — June 2012
  19. 19webSummary Statistics
  20. 20bookThe adequacy of the fossil recordM.J. Benton — Wiley — 1998
  21. 21harvnbNelson (2016) p. 3Nelson — 2016
  22. 22journalSizing ocean giants: patterns of intraspecific size variation in marine megafaunaCraig R. McClain et al. — 2015-01-13
  23. 23journalPaedocypris, a new genus of Southeast Asian cyprinid fish with a remarkable sexual dimorphism, comprises the world's smallest vertebrateMaurice Kottelat et al. — 2005
  24. 24journalGlobal determinants of freshwater and marine fish genetic diversityStéphanie Manel et al. — 2020-02-10
  25. 25journalCryptic Diversity in Indo-Pacific Coral-Reef Fishes Revealed by DNA-Barcoding Provides New Support to the Centre-of-Overlap HypothesisNicolas Hubert et al. — 2012-03-15
  26. 26bookEncyclopedia of Inland WatersPeter van der Sleen et al. — Elsevier — 2022
  27. 27journalAquatic Biodiversity in the Amazon: Habitat Specialization and Geographic Isolation Promote Species RichnessJames S. Albert et al. — June 2011
  28. 28journalMarine fish may be biochemically constrained from inhabiting the deepest ocean depthsP.H. Yancey et al. — 2014
  29. 29webWhat is the deepest-living fish?23 December 2014
  30. 30journalSupercooled Southern Ocean WatersF. Alexander Haumann et al. — 2020-10-28
  31. 31journalA vast icefish breeding colony discovered in the AntarcticAutun Purser et al. — 2022
  32. 32webDesert Pupfish (Cyprinodon macularius) Recovery PlanPaul C. Marsh et al. — United States Fish and Wildlife Service — 1993
  33. 33journalEffects of Constant and Fluctuating Temperatures on Reproductive Performance of a Desert Pupfish, Cyprinodon n. nevadensisJoy B. Shrode et al. — 1977
  34. 34bookBeach-Spawning Fishes: Reproduction in an Endangered EcosystemK.L.M. Martin — CRC Press — 2014
  35. 35webCat-eLog: Heptapteridae: Phreatobius: Phreatobius sp. (1)
  36. 36journalSpatial organization and population density of the fish community of the litter banks within a central Amazonian blackwater streamP.A. Henderson et al. — 1990
  37. 37bookFish Conservation: A Guide to Understanding and Restoring Global Aquatic Biodiversity and Fishery ResourcesG.S. Helfman — Island Press — 2007
  38. 38journalA Cleaning Symbiosis between the Cichlid Fishes Etroplus maculatus and Etroplus suratensis. I. Description and Possible EvolutionRichard L. Wyman et al. — 1972
  39. 39journalRapid worldwide depletion of predatory fish communitiesRansom A. Myers et al. — Springer Science and Business Media — 2003
  40. 40webPredationNorthwest Power and Conservation Council
  41. 41journalReview of Fish Swimming Modes for Aquatic LocomotionM. Sfakiotakis et al. — 1999
  42. 42webActinopterygii: More on MorphologyUniversity of California Museum of Paleontology
  43. 43journalStructure and Mechanical Adaptability of a Modern Elasmoid Fish Scale from the Common CarpHaocheng Quan et al. — 2020
  44. 44bookThe Biology of the Deep OceanPeter Herring — Oxford University Press — 2002
  45. 45webAnimal Circulatory SystemsGeorgia Tech
  46. 46bookThe Vertebrate BodyAlfred Sherwood Romer et al. — Holt-Saunders International — 1977
  47. 47bookRespiratory Physiology of VertebratesJeffrey B. Graham et al. — Cambridge University Press — 2010
  48. 48journalModifications of the Digestive Tract for Holding Air in Loricariid and Scoloplacid CatfishesJonathan W. Armbruster — 1998
  49. 49webDigestive SystemUniversity of Tennessee
  50. 50bookOxford Scholarship OnlineDerek Burton et al. — Oxford University Press — 2017-12-21
  51. 51journalFish gills: mechanisms of salt transfer in fresh water and sea waterJ. Maetz — 1971-08-20
  52. 52journalLateral line system of fishHorst Bleckmann et al. — 2009-03-01
  53. 53bookMetazoaPeter Godfrey-Smith — Farrar, Straus and Giroux — 2020
  54. 54bookThe Physiology of FishesJ. S. Albert et al. — CRC Press — 2006
  55. 55bookThe Behaviour of Teleost FishesD. M. Guthrie — Springer — 1986
  56. 56journalUltraviolet Polarization Vision and Visually Guided Behavior in FishesCraig W. Hawryshyn — 2010
  57. 57journalReview of larval and postlarval eye ultrastructure in the lamprey (cyclostomata) with special emphasis on Geotria australis (gray)V. Benno Meyer-Rochow et al. — 1996
  58. 58journalEvolution of the vertebrate eye: opsins, photoreceptors, retina and eye cupTrevor D. Lamb et al. — 2007
  59. 59bookHearing and Sound Communication in FishesA. D. Hawkins — Springer — 1981
  60. 60journalEvidence for celestial and magnetic compass orientation in lake migrating sockeye salmon fryThomas P. Quinn — 1980
  61. 61journalExperimental evidence for geomagnetic orientation in juvenile salmon, Oncorhynchus tschawytscha WalbaumP. B. Taylor — May 1986
  62. 62journalMagnetoreception in fishKrzysztof Formicki et al. — 2019
  63. 63journalThe Quantum Nature of Bird MigrationPeter J. Hore et al. — April 2022
  64. 64journalContingency checking and self-directed behaviors in giant manta rays: Do elasmobranchs have self-awareness?Csilla Ari et al. — 2016-05-01
  65. 65journalCleaner wrasse pass the mark test. What are the implications for consciousness and self-awareness testing in animals?Masanori Kohda et al. — 2018-08-21
  66. 66magazineFishes Use Problem-Solving and Invent ToolsJonathan Balcombe — 1 May 2017
  67. 67journalPair-bonding influences affective state in a monogamous fish speciesChloé Laubu et al. — 2019
  68. 68webAppropriate maze methodology to study learning in fishJournal of Undergraduate Life Sciences
  69. 69webThe face of the fishMichael Woodruff — 3 July 2020
  70. 70journalActive electrolocation of objects in weakly electric fishG. von der Emde — 15 May 1999
  71. 71journalElectric eels use high-voltage to track fast-moving preyKenneth C. Catania — 20 October 2015
  72. 72journalEndothermy in fishes: a phylogenetic analysis of constraints, predispositions, and selection pressuresB.A. Block et al. — 1993
  73. 73journalWhole-body endothermy in a mesopelagic fish, the opah, Lampris guttatusNicholas C. Wegner et al. — 2015-05-15
  74. 74journalRegulation of body temperature in the white shark, Carcharodon carchariasK.J. Goldman — 1997
  75. 75journalTemperature regulation in free-swimming bluefin tunaF.G. Carey et al. — February 1973
  76. 76journalGonadal structure and gametogenesis of Loricaria lentiginosa Isbrücker (Pisces, Teleostei, Siluriformes)Rodrigo J. Guimaraes-Cruz — July–September 2005
  77. 77journalReproduction of the surubim catfish (Pisces, Pimelodidae) in the São Francisco River, Pirapora Region, Minas Gerais, BrazilM.F.G. Brito — 2003
  78. 78bookLivebearing FishesPeter Scott — Tetra Press — 1997
  79. 79bookEarly Life History of Marine FishesBruce Miller et al. — University of California Press — 2009
  80. 80journalDNA repair genes play a variety of roles in the development of fish embryosAbhipsha Dey et al. — 2023
  81. 81journalZebrafish (Danio rerio) using as model for genotoxicity and DNA repair assessments: Historical review, current status and trendsAryelle Canedo et al. — 2021
  82. 82journalOrigin and evolution of the adaptive immune system: genetic events and selective pressuresM. F. Flajnik et al. — 2010
  83. 83bookThe Fish Immune System: Organism, Pathogen and EnvironmentA.G. Zapata et al. — Academic Press — 1996
  84. 84journalThe thymus in fish: development and possible function in the immune responseS. Chilmonczyk — 1992
  85. 85journalLymphocyte development in fish and amphibiansJ.D. Hansen et al. — 1998
  86. 86bookThe Behaviour of Teleost FishesTony J. Pitcher — Springer — 1986
  87. 87journalThe population biology and exploitation of capelin (Mallotus villosus) in the Barents SeaH. Gjøsæter — 1998
  88. 88journalTerritorial vocalization in sympatric damselfish: acoustic characteristics and intruder discriminationS.R. Weinmann et al. — February 2017
  89. 89journalNew Insights into the Role of the Pharyngeal Jaw Apparatus in the Sound-Producing Mechanism of Haemulon flavolineatum (Haemulidae)F. Bertucci et al. — 29 October 2014
  90. 90journalSound production during feeding in Hippocampus seahorses (Syngnathidae)D.J. Colson et al. — February 1998
  91. 91journalSounds produced by the longsnout seahorse: a study of their structure and functionsT.P.R. Oliveira et al. — 26 June 2014
  92. 92journalAcoustical properties of the swimbladder in the oyster toadfish Opsanus tauL.F. Fine et al. — 16 October 2009
  93. 93journalGrunt variation in the oyster toadfish Opsanus tau: effect of size and sexM.L. Fine et al. — 15 October 2015
  94. 94journalOyster toadfish (Opsanus tau) boatwhistle call detection and patterns within a large-scale oyster restoration siteS.W. Ricci et al. — 8 August 2017
  95. 95journalFunctional analysis of swimbladder muscles engaged in sound productivity of the toadfishC.R. Skoglund — 1 August 1961
  96. 96journalSound production in Sciaenops ocellatus: Preliminary study for the development of acoustic cues in aquacultureE. Parmentier et al. — 22 May 2014
  97. 97webSearch for 'Fishes' (Global, CR-Critically Endangered, En-Endangered, Species)
  98. 98iucnGadus morhuaJ. Sobel 0 — 1996
  99. 99iucnCyprinodon diabolisNatureServe — 2014
  100. 100iucnLatimeria chalumnaeJ.A. Musick — 2000
  101. 101iucnCarcharodon carchariasRigby, C.L. — 2022
  102. 102bookThe State of World Fisheries and Aquaculture 2020Food and Agriculture Organization — 2020
  103. 103newsCall to halt cod 'over-fishing'5 January 2007
  104. 104newsTuna groups tackle overfishing26 January 2007
  105. 105journalOutport adaptations: Social indicators through Newfoundland's Cod crisisLawrence C. Hamilton et al. — January 2001
  106. 106newsUK 'must shield fishing industry'3 November 2006
  107. 107newsEU fish quota deal hammered out21 December 2006
  108. 108webOcean study predicts the collapse of all seafood fisheries by 2050
  109. 109webAtlantic bluefin tuna could soon be commercially extinctWWF
  110. 110journalConservation status of endemic freshwater fish in SpainBenigno Elvira — Elsevier — 1995
  111. 111bookThe influence of dams on river fisheriesDonald C. Jackson et al. — FAO Fisheries — 2001
  112. 112journalExtinction Debt and Colonizer Credit on a Habitat Perturbed Fishing BankDaniel E. Duplisea et al. — Public Library of Science (PLoS) — 2016
  113. 113journalThe economic impacts of aquatic invasive species: a review of the literatureSabrina J. Lovell et al. — 2006
  114. 114bookThe Economics of Biological InvasionsD. Knowler et al. — Edward Elgar — 2000
  115. 115bookAtlas of Exotic Fishes in the Mediterranean SeaCIESM Publishers — 2021
  116. 116journalImpact of Red Sea fish migrants through the Suez Canal on the aquatic environment of the Eastern MediterraneanDaniel Golani — 1998
  117. 117journalUnique qualities and special problems of the African Great LakesGeorge W. Coulter et al. — Springer Science and Business Media — 1986
  118. 118journalThe impact of the introduction of the Nile Perch, Lates niloticus (L.), on the fisheries of Lake VictoriaA. P. Achieng — 1990
  119. 119magazineSustainable Ancient AquacultureMark Spalding — 11 July 2013
  120. 120bookFish Conservation: A Guide to Understanding and Restoring Global Aquatic Biodiversity and Fishery ResourcesGene S. Helfman — Island Press — 2007
  121. 121bookThe State of World Fisheries and Aquaculture 2022. Towards Blue TransformationFood and Agriculture Organization — 2022
  122. 122bookThe Angler in the Environment: Social, Economic, Biological, and Ethical DimensionsAmerican Fisheries Society — 2011
  123. 123bookRecreational Fisheries: Social, Economic and Management AspectsWiley-Blackwell — 1998
  124. 124bookGods, Demons and Symbols of Ancient Mesopotamia: An Illustrated DictionaryJeremy Black et al. — The British Museum Press — 1992
  125. 125bookPaganism to Christianity in the Roman EmpireWalter Woodburn Hyde — Wipf and Stock Publishers — 2008
  126. 126bookA Biblical Text and Its Afterlives: The Survival of Jonah in Western CultureYvonne Sherwood — Cambridge University Press — 2000
  127. 127magazineWhat is the origin of the Christian fish symbol?Elesha Coffman — 8 August 2008
  128. 128web'Ngārara – reptiles, Page 2. From sea to land', Te Ara – the Encyclopedia of New ZealandBradford Haami
  129. 129bookHawaiian Folk TalesThomas Thrum — A. C. McClurg — 1907
  130. 130bookClass and Religion in Ancient IndiaJayantanuja Bandyopadhyaya — Anthem Press — 2007
  131. 131journalIntroduction to fish imagery in artPeter B. Moyle et al. — May 1991
  132. 132journal'Fish Are Just like People, Only Flakier': Environmental Practice and Theory in Finding NemoChristy Tidwell — 2009
  133. 133journalNature of Existential Struggle in The Old Man and the SeaP. Durga et al. — 2017
  134. 134bookThis shark, swallow you whole": Essays on the Cultural Influence of JawsJay Alabaster — McFarland — 2023
  135. 135webPiranha – Ferocious Fighter or Scavenging Softie?Sue Anne Zollinger — Indiana Public Media — 3 July 2009