fish fish member group organisms consist gill bearing aquatic animals lack limbs included definition living bony fish extinct related groups fish cold allowing body temperatures vary ambient temperatures change large active swimmers like white shark hold higher core temperature fish abundant bodies water found nearly aquatic environments high mountain streams depths deepest oceans described species fish exhibit greater species diversity group fish important resource humans worldwide especially food commercial hunt fish wild fisheries fishing farm ponds ocean caught recreational kept pets raised exhibited public fish role culture ages serving deities religious symbols subjects art books movies term fish defined negatively amphibians reptiles birds mammals descend ancestry considered proper grouping systematic biology traditional term considered phylogenetic classification earliest organisms classified fish soft bodied appeared period lacked true spine possessed allowed counterparts fish continue evolve era wide variety forms fish developed external armor protected predators fish jaws appeared period sharks formidable marine predators prey evolution fish represent group evolution fish studied single event early fish fossil record represented group small armored fish known fish extinct extant clade approximate ancient pre fish jaws found fossils diversity indicate evolutionary advantage mouth unclear advantage jaw greater biting force improved combination factors fish evolved creature similar coral like sea larvae resemble primitive fish important ways ancestors fish kept form adulthood sea today reverse case taxonomy fish group clade containing fish contains fish reason groups class seen older reference works longer formal classifications traditional classification divide fish extant classes extinct forms classified tree classes class fish armoured fish class fish sharks rays extinct relatives class armoured fish class sharks classified bony fishes class bony fish ray fishes fishes ancestors scheme commonly encountered non specialist general works groups given rise successive groups ancestral given rise ancestors arrival phylogenetic nomenclature fishes split detailed scheme following major groups class class early fish class class class class class early fish class armoured fish class fish class sharks bony fish class ray fish order orders common fish class lobe fish indicates extinct taxon contend primitive fish fuller treatment taxonomy article position settled phylogenetic research supported idea form natural group sister group fish groups account half species known extant species bony fish sharks rays species fall largest families largest smallest families families containing species final total extant species grow exceed diversity term fish precisely describes non animal skull cases backbone gills life limbs shape fins unlike birds mammals fish single clade collection taxa including sharks rays ray fish closer relatives mammals birds amphibians etc fish ray fish sharks common ancestor fish ancestor groups longer recognised modern systematic biology use term fish biological group avoided types aquatic animals commonly referred fish fish sense given examples include earlier times distinction sixteenth century natural historians classified seals amphibians host aquatic invertebrates fish according definition mammals including like fish contexts especially true fish referred fin fish distinguish animals typical fish streamlined body rapid swimming extracts oxygen water gills uses breathing organ breathe atmospheric oxygen sets paired fins usually rarely dorsal fins anal fin tail fin jaws skin usually covered scales lays eggs criterion exceptions species sharks warm adaptations heat bodies significantly ambient water temperature swimming performance varies fish salmon cover body lengths second species rays swim body lengths second groups freshwater fish extract oxygen air water variety different structures paired lungs similar structure called labyrinth organ performs similar function extract oxygen stomach body shape arrangement fins highly variable covering seemingly forms similarly surface skin naked covered scales variety different types usually defined typical sharks rays fossil fossil fish living found bony fish fish live land feed interact underwater hide lives underground habitats relative lives leaf litter fish range size huge metre whale shark tiny millimetre stout fish species diversity roughly divided equally marine oceanic freshwater ecosystems coral reefs constitute center diversity marine fishes continental freshwater fishes diverse large river basins tropical especially amazon basins fish species inhabit fishes represent species earth exceptionally rich sites amazon basin state park contain freshwater fish species occur europe anatomy gills fish exchange gases gills gills consist structures called contains network provides large surface area exchanging oxygen carbon dioxide fish exchange gases pulling oxygen rich water mouths pumping gills fish blood flows opposite direction water causing exchange gills push oxygen poor water openings sides fish like sharks possess multiple gill openings bony fish single gill opening opening hidden beneath protective bony cover called juvenile external gills primitive feature share amphibians air breathing fish multiple groups live water extended periods amphibious fish live land days live oxygen depleted water fish breathe air variety mechanisms skin absorb oxygen directly cavity electric breathe air families absorb air digestive tracts exception australian paired lungs similar surface fresh air mouth pass spent air gills swim functions way breathe passing air gut breathe absorbing oxygen skin similar frogs number fish evolved called breathing organs extract oxygen air labyrinth fish labyrinth organ gills performs function fish structures resembling labyrinth organs form function notably family breathing air primarily use fish inhabit shallow variable waters water oxygen concentration decline fish dependent solely dissolved oxygen perch quickly air survive longer cases water little wet mud extreme air breathing fish able survive damp weeks water entering state water returns air breathing fish divided air air air african breathe air periodically air breathe air need rely gills oxygen air breathing fish air avoid energetic cost rising surface fitness cost exposure surface predators circulation fish closed loop system heart pumps blood single loop body fish heart consists parts including chambers entrance exit thin walled sac collects blood fish veins allowing flow second large muscular chamber serves way sends blood thick walled muscular chamber pumps blood fourth large tube heart connects blood flows gills jaws allow fish eat wide variety food including plants organisms fish food mouth break stomach food fish processed finger shaped called digestive absorb nutrients organs liver add chemicals food moves digestive tract completes process nutrient absorption aquatic animals fish release gills blood filtered fish tend lose water return water body reverse happens freshwater fish tend gain water produce fish specially adapted vary function allowing freshwater scales scales fish originate skin similar structure teeth sensory nervous system central nervous system fish typically small brains relative body size compared typically fifteenth brain mass similarly sized bird fish relatively large brains notably sharks brains massive relative body weight birds fish brains divided regions pair structures receive process signals nostrils nerves large fish hunt primarily smell sharks structural equivalent higher fish concerned structures form connecting structure consequently visible performs functions associated body lies structure light maintains rhythms controls color changes contains large species hunt sight rainbow trout particularly involved swimming balance single structure typically biggest brain relatively small massive apparently involved electrical sense brain stem brain posterior controlling muscles body organs bony fish brain stem sense organs fish possess highly developed sense organs nearly daylight fish color vision good human vision fishes fish responsible extraordinary senses taste smell ears fish hear fish sensitive form lateral line system gentle currents vibrations senses motion nearby fish prey fish sharks organs detect weak electric currents order fish like south american electric fishes produce weak electric currents use navigation social communication fish orient landmarks use mental maps based multiple landmarks symbols fish behavior reveals possess spatial memory visual discrimination vision vision important sensory system species fish fish eyes similar terrestrial like birds mammals spherical lens generally rods vision species colour vision fish light fish developed eyes primitive fish vision shows adaptation visual environment example deep sea fishes eyes suited dark environment hearing hearing important sensory system species fish fish sense sound lateral lines ears capacity pain experiments provide evidence fish pain fear responses instance experiments electrically shocked time came mere sight scottish scientists concluded rainbow trout exhibit behaviors associated pain animals bee venom acid injected lips resulted fish rocking bodies lips sides floors tanks researchers concluded attempts relieve pain similar mammals fired pattern resembling human patterns professor claimed study flawed provide proof fish possess conscious awareness particularly kind awareness like rose argues fish brains different human brains fish probably conscious manner humans reactions similar human reactions pain instead causes rose published study year earlier arguing fish feel pain brains lack animal argues fish consciousness different species use different brain structures systems handle functions animal welfare advocates raise concerns possible suffering fish caused countries germany banned specific types fishing british formally individuals cruel fish muscular system fish alternately contracting paired sets muscles backbone form shaped curves body curve reaches fin backward force applied water conjunction fins moves fish forward fish fins function like airplane flaps fins increase tail surface area increasing speed streamlined body fish decreases friction water body tissue water fish compensate difference sink bony fish internal organ called swim manipulation gases fish exclusively exceptions certain species fish maintain elevated body temperatures bony fish include species primitive sharks family long fin white salmon shark evidence suggests trait exists family sharks degree varies warm eyes brain sharks maintain body temperatures elevated excess ambient water temperatures costly thought provide advantages increased muscle strength higher rates central nervous system processing higher rates reproductive system fish reproductive organs include species paired organs similar size partially totally fused range secondary organs increase reproductive fitness terms distribution structure types common occur fish confined portion structures fish present semi relation release phase cells fish types secondary type released directly cavity enter eliminated secondary shed directly type conveyed exterior primitive condition found characterize continuity secondary found development fish varies according group determination dynamics allows understanding maturation processes changes nucleus surrounding layers characterize maturation process structures formed release function present wide irregular rapidly process involving cells process called spawned process occur frequently development stages fish like california having different phases life cycle simultaneously known fish eggs develop outside mother body examples fish include salmon majority species takes place outside mother body male female fish surrounding water fish practice internal male sort organ deliver sperm opening female notably sharks horn shark rays cases male equipped pair modified pelvic fins known marine fish produce high numbers eggs released open water column eggs average diameter millimetre newly hatched young fish called larvae usually poorly formed carry large yolk sac different appearance juvenile adult specimens period fish relatively short usually weeks larvae rapidly grow change appearance structure process termed juveniles transition larvae switch yolk sac feeding prey process depends typically inadequate density larvae fish eggs develop inside mother body internal receive little directly mother depending instead yolk embryo develops egg familiar examples fish include angel sharks species fish viviparous species mother retains eggs embryos typically viviparous fish structure analogous seen mammals connecting mother blood supply embryo examples viviparous fish include surf lemon shark viviparous fish exhibit developing embryos eat eggs produced mother observed primarily sharks known bony fish unusual mode largest embryos eat weaker smaller siblings behavior commonly found sharks grey nurse shark reported commonly refer viviparous fish diseases like animals fish suffer diseases parasites prevent disease variety defenses non specific defenses include skin scales layer traps growth breach defenses fish develop response increases blood flow infected region delivers white blood cells attempt destroy specific defenses respond particular recognised fish body immune response recent years widely ornamental fish example farmed salmon virus species use cleaner fish remove external parasites best known cleaner genus found coral reefs indian pacific oceans small fish maintain called cleaning stations fish perform specific movements attract attention cleaning behaviors observed number fish groups including interesting case genus cleaner larger immune system immune organs vary type fish fish true organs absent fish rely regions tissue organs produce immune cells example cells produced anterior kidney areas gut mature resemble primitive bone fish sharks rays advanced immune system specialized organs unique organs tissue similar bone surround organ walls spiral valve organs house typical immune cells cells possess identifiable developed important immune organ cells develop stored fish possess major site production mass associated membranes surrounding central nervous system heart frequently covered tissue contains cells small number kidney important organ develop like fish major immune tissues bony fish include kidney especially anterior kidney houses different immune cells addition fish possess scattered immune areas tissues skin gills gut like immune system believed reside major cell type found system similar mammals described species fish confirmed system presumably naive cells accumulate waiting encounter bearing cell respectively found fishes immune system evolved ancestor conservation iucn red list names fish species threatened extinction included species atlantic devil hole great white sharks fish live underwater difficult study terrestrial animals plants information fish populations lacking freshwater fish particularly threatened live relatively small water bodies example devil hole occupies single metres pool major threat edible fish eventually causes population known stock collapse survivors produce young replace removed commercial extinction mean species extinct merely longer sustain fishery studied example fishery collapse pacific fishery california coast peak long tons catch steadily declined long tons fishery longer economically viable main tension fisheries science fishing industry groups different views fisheries intensive fishing places scotland newfoundland alaska fishing industry major employer governments support hand scientists push stringent protection warning stocks wiped years habitat destruction key stress freshwater marine ecosystems habitat degradation including water pollution building dams removal water use humans introduction exotic species example fish endangered habitat change north american freshwater fish lives rivers damaged human activity exotic species introduction non native species occurred habitats best studied examples introduction perch 1960s perch gradually lake endemic species survive captive breeding programmes probably extinct european perch brown trout rainbow trout sea examples fish caused problems introduced alien environments importance humans economic importance history humans utilized fish food source historically today fish protein come means catching wild fish fish farming practiced bce china increasingly important nations overall sixth world protein estimated provided fish proportion considerably elevated developing nations regions heavily dependent sea similar manner fish tied trade catching fish purpose food sport known fishing organized effort humans catch fish called fishery fisheries huge global business provide income millions people annual yield fisheries worldwide million tons popular species including herring salmon term fishery broadly applied includes organisms fish crustaceans called fish food recreation fish recognized source beauty long food appearing cave art raised ornamental fish ponds displayed homes offices public settings recreational fishing fishing pleasure competition contrasted commercial fishing fishing profit common form recreational fishing rod reel line hooks wide range method fishing specifically practice catching fish means angle hook select right hook cast accurately retrieve right speed considering water weather conditions species fish response time day factors culture fish feature prominently art literature movies books old man sea large fish particularly sharks frequently subject horror movies notably novel jaws spawned series films turn inspired similar films parodies terror shown similar light sharks films contrary popular belief red actually generally species unlikely harm humans book great fish legends half human half fish featured folklore like stories fish themes symbolic significance religions fish symbol christians represent jesus christianity general refer men feeding multitude buddhism fish symbolize happiness complete freedom movement water drawn form regarded orient sacred account elegant beauty size life span deities said form fish ancient semitic peoples shark gods symbol based second fish night sky terminology school random fish merely resource food nesting sites known simply fish come interactive social grouping forming school depending degree organisation loosely organised group fish independently attracted members group behaviour swimming speed remains close members group schools fish tightly organised swimming fish speed direction schooling behaviour believed provide variety advantages examples sites form form classic examples schooling fish words school different meanings biology treated synonyms non specialists speakers british english describe grouping fish speakers american english school loosely fish fishes biology words different meanings fish singular describe multiple individuals single species fishes describe different species species groups pond contained single species said contain fish pond contained total fish different species said contain fishes distinction similar people peoples biology term fish strictly describe animal backbone gills life limbs shape fins types aquatic animals common names ending fish fish sense examples include earlier times distinction sixteenth century natural historians classified seals amphibians host aquatic invertebrates fish fisheries term fish collective term includes crustaceans aquatic animal harvested strict biological definition fish called true fish true fish referred fin fish distinguish aquatic life harvested fisheries
Fish