murray murray large australian predatory freshwater fish genus family species called vernacular related marine species murray important australia wildlife found murray river system australia murray largest exclusively freshwater fish australia largest world common names murray include murray perch queensland freshwater scientific murray derives early australian fish researcher surname river explorer major mitchell scientifically described species number years changed differentiate murray designated subspecies murray raised species status murray reverted simply murray populations declined severely european australia number causes including severe river regulation habitat degradation listed threatened species inhabited entire murray basin australia largest river system great numbers long lived fish adult murray mainly eat fish species exhibits high degree parental care eggs spawned spring generally laid hollow logs hard surfaces murray popular target species available trade popular species australia description murray large like fish deep elongated body round cross section broad head large mouth lined pads small needle like teeth jaws murray equal lower jaw slightly dorsal fin murray moderate low height partially separated notch high rounded soft dorsal fin soft dorsal anal caudal tail fins large rounded grey black distinct white edges large rounded pectoral fins usually similar colour flanks pelvic fins large angular set forward pectoral fins leading white coloured rays pelvic fins split trailing white pelvic fins usually translucent white cream tending large fish murray white cream ventral belly surfaces backs flanks usually yellowish green green heavy darker green occasionally brown black effect appearance reminiscent leopard markings related water clarity intense fish clear water habitats small medium sized murray clear water habitats striking distinct large fish tend grey green size murray large fish adult fish regularly reaching length smallest waterways murray capable growing length largest record weight large breeding fish rare wild populations today related species murray continue pattern present native fish genera lowland specialist species murray primarily lowland species endangered trout specialist species pattern slightly blurred species successful fish murray push significant distances habitats endangered trout stray stray decline lowland transition zone extensive basic pattern primarily lowland species specialist species present murray like number murray native fish species managed cross great dividing range natural river capture events leading species subspecies coastal best known eastern freshwater system northern new_south_wales system south eastern queensland endangered survive today coastal found system northern new_south_wales system southern queensland extinct taxonomy 1800s early 1900s commercial fishermen recreational fishermen riverside residents fisheries scientists anderson distinctly recognised species southern murray basin murray trout blue nose confusion ignoring differences size sexual maturity reasoning prominent fisheries scientists insisted recognising species murray named early australian fish researcher surname new_south_wales captured trout declined near extinction 1900s distinction species eroded finally questioned 1970s early genetic techniques confirmed trout separate species showed original murray specimen fact trout following rules scientific classification remained original specimen known trout new new captured coined murray subsequently identified separate species eastern freshwater range murray named murray basin eastern australia australia largest important river system draining continent murray natural range encompasses virtually murray basin particularly lowland areas extending areas elevation southern half basin northern half basin consequently murray inhabit remarkably wide variety habitats cool clear fast flowing streams pool structure rocky areas large slow flowing rivers extensive lowland reaches murray basin murray died habitats particularly southern murray basin combination dams blocking migration pollution based sheep mining cases introduced trout causes competition juvenile murray introduced trout species age murray long lived characteristic freshwater native fish australia longevity survival strategy variable australian environment ensure adults participate exceptional spawning recruitment event linked unusually wet years occur decades murray long lived freshwater native fish australia oldest murray aged years age larger specimens years past leave little doubt species reach considerably greater ages years diet murray apex aquatic predator rivers murray basin eat smaller including fishes smaller murray golden perch silver perch bony tailed western australian introduced fish english perch crustaceans freshwater shrimp murray fish compose majority diet mature murray lowland river habitats murray apex predators habitats murray known eat ducks freshwater turtles water dragons snakes mice frogs observations recreational fishermen fishing murray surface night reveal popular description murray ambush predator partially correct behaviour typical day night murray active predators shallow waters frequently taking prey surface reproduction murray reach sexual maturity years age generally years sexual maturity murray dependent age roughly wild river murray slower growth rate reached sexual maturity length like faster growth rates reach sexual maturity length data strongly indicate size limit murray inadequate increased substantially allow greater chance reproduction capture large female murray range important breeders produce eggs reasons large females fish species important produce larger larvae larger yolk experienced breeders display optimal breeding large females valuable successful genes pass factors mean large female fish far higher survival rates far greater reproductive contributions small female fish reaching sexual maturity egg counts large female murray egg counts high recent large specimen yielded egg count viable eggs egg counts female murray sizes relatively low compared fish species murray spawn spring rising water temperatures increasing daylight length initially fish working murray considered spring floods temperatures necessary spring flooding critical successful recruitment survival juvenile stages young providing influx early life stage flood plain main river channel feeding recent research shown murray breed annually spring floods temperatures low additionally recent research shown abundant dwelling edge prey lowland rivers traits murray larvae allow survival variety challenging conditions significant proportion murray larvae feeding successfully rivers latest research shown murray fact live entire main channel stream earlier ideas murray spawn larvae feed incorrect murray breed main river channel times spring flood inundated upper portion main channel tributary channels murray larvae feed main river channel times spring flood inundated upper portion main channel channel boundary spawning preceded significant upstream high spring flows floods allow radio tracked murray migrated upstream spawn returning exactly departed unusual behaviour freshwater fish decades observations recreational commercial fishermen suggest spring spawning common murray geographical range spawning initiated pairing courtship rituals courtship ritual spawning site selected cleaned hard surfaces rocks rivers logs occasionally clay banks lowland rivers depth metres selected female lays large eggs mat spawning surface male female leaves spawning site male remains guard eggs takes days depending water temperature guard hatched larvae week disperse larvae disperse nest site drifting river currents night continue behaviour seven days dispersal process larvae simultaneously absorb remainder yolk sac begin feed small early life stage dwelling edge relationship river flows murray recruitment complex thought regulated rivers murray able recruit range conditions including stable low flows significant recruitment murray low flow conditions regulated lowland rivers proven information suggests regulation related causes degradation playing larger role survival recruitment murray larvae thought competition extremely large numbers invasive larvae negatively affecting survival recruitment murray larvae greater degree thought decades playing far larger role current state murray stocks spawning adults thought findings mean river regulation water extraction adverse effects fish stocks river regulation major factor decline murray native fish thermal pollution major problem evidence indicates strong murray recruitment events important sustaining murray populations long term result spring flooding health australian lowland river ecosystems generally rely periodic spring flooding regulation rivers murray river system mainly irrigation purposes exceptional spring floods manage break free long term viability wild murray native fish species river ecosystems face fact great concern conservation murray originally common large native fish murray basin contrary fishery department literature declines murray caused extremely severe half 1800s early 1900s murray large long lived fish caught numbers commercial recreational fishermen example commercial fishing operation commenced near targeting murray hundreds kilometres river years grave concerns operation complaints near absence murray heavily grounds raised main state newspaper fishing effort continued increase region late 1880s early 1890s murray fish average weight caught near similarly murray sent melbourne river town 1920s murray point large scale commercial fishing operations longer feasible recreational fishermen took similarly excessive era rods drum nets gill nets explosives wasted illegally sold extreme impacts wild murray stocks best summarised short article south australian newspaper years nearly tons murray eaten people melbourne included figures statement today pointing supply declining peak year received market sent melbourne supply decreased year incredibly years later aquatic compelled extremely heavy fishing pressure form small scale commercial fishing rampant illegal fishing confronted reaches investigated thorough reading historical newspaper articles historical government reports reveals history wild murray mid 1800s mid 1900s citizen government ongoing stock decline decade decade riverside residents commercial fishermen recreational fishermen local fisheries fish retailers agitated newspapers evidently continuously declining murray stocks met turn government conversely ineffective inquiries murray stocks fisheries ineffective control measures decade decade debate excessive fishing pressure number fishermen number nets net size bag limits minimum size limits small closed seasons taking spawning eggs spring issues proper resolution fishing regulations amended amended largely completely ignored heavy commercial recreational illegal fishing pressure continuing end result murray population initially abundant continually pause early mid 20th century number factors river regulation listed emerged drive species decline drivers decline left iconic australian fish situation grave concerns long term survival wild murray populations effects disregarded overall picture today recent population studies shown year classes represented minimum legal size centimetres states size numbers fish dramatically reduced point non existence waters emphasis results small surveys suggested majority murray released valid questions surveys surveys explain dramatic disappearance large numbers young murray exactly minimum size limit importantly emphasis surveys miss fundamental point large long lived species relatively low delayed sexual maturity wild murray populations extremely vulnerable modest kill fishing regulations wild murray referred switch fishermen largely catch release approach wild murray alleviate problem recognising issues late new_south_wales victorian fishery departments amended regulations slot limit applies states murray taken size range slot released measure positive effects murray population protecting increasing proportion large breeding murray issue murray caught released winter developing eggs spring prior spawning eggs spawn minor issue compared threats facing murray concerned fishermen try avoid catching wild murray times point time closed season place spring spawning period allowed target murray catch release basis departments support murray populations bred fish especially man lakes important issues affecting restoration populations need spring floods excessive slowly acknowledged definitely addressed effects river regulation southern tributaries originally displayed pattern high flows winter high flows floods spring low flows summer autumn breeding murray murray native fish adapted natural flow patterns river regulation irrigation reversed natural flow patterns negative effects breeding recruitment murray murray southern tributaries experience high irrigation flows summer autumn low flows winter spring small medium floods including annual spring flood pulse completely eliminated estimated flows river mouth declined natural probability end murray experiencing drought like flows increased natural conditions thermal pollution artificial reduction water temperatures especially summer autumn caused water released irrigation demands temperature suppression typically extends kilometres downstream thermal pollution breeding murray survival murray larvae extreme cases survival adult murray rare floods break free dams murray system magnitude duration deliberately curtailed river increasing research indicates management practice harmful drastically reduces general ecosystem benefits breeding recruitment opportunities murray murray native fish species rare floods provide physical barriers fish movement dams barriers block migration adult juvenile murray prevent habitats maintenance isolated populations additionally recent study proven approximately murray larvae killed pass habitat degradation hundreds thousands million submerged timber mainly removed lowland reaches murray basin past years removal vast number devastating impacts murray river ecosystems critical habitats spawning sites murray critical functioning lowland river ecosystems hard lowland river channels composed fine crucial sites growth grazing general stream productivity vegetation clearing cattle river banks create severe fill pools river ecosystems rivers streams murray exacerbated removal vegetation causes river ecosystems ways extremely severe commercial recreational 1800s early 1900s caused strong declines murray recreational fishermen aided inadequate fishing regulations continues today remains extremely threat murray current size limit centimetres states inadequate scientific studies documented average size sexual maturity murray catch data computer modelling exercises wild murray stocks indicate measures raising size limit centimetres reducing bag possession limits fish respectively fish needed maintain long term viability wild murray populations november introduced maximum size limit provide protection large breeding fish new minimum size limit introduced evidence mounting competition food early juvenile introduced early juvenile native fish introduced dominate fish lowland rivers sheer large numbers larvae produce causes negative effects river ecosystems native fish main introduced parasite introduced asian fish introduced murray soft skin fine scales leave vulnerable infection exotic disease organisms following exotic disease organisms seriously affect wild murray introduced imports exotic fish single parasitic skin murray caused number kills wild murray fungus like water mould frequently murray eggs skin murray roughly handled poor catch release technique essential murray intended release touch cool wet surfaces hard dry rough hot surfaces boat boat floors dry grass dry rocks gravel banks dry etc hands touching populations range suffer extremely severe anchor worm parasitic introduced skin murray wounds infected bacteria severe probably causes death adult murray commonly recognised reports young adult murray seemingly killed severe relationship humans murray play important role mythology tribes murray basin tribes particular living murray icon species myths tribes describe creation gigantic murray fleeing small creek escape renowned hunter myths fleeing murray river beating tail create bends eventually near terminus pieces pieces thrown river pieces fish species river head kept intact told murray thrown river additional references advice minister environment heritage amendments list pertaining murray act act retrieved june version
Murray cod