Chinesesturgeonisatypicalanadromousspecies,spendingmostofitslifeinsaltwaterandreturningtofreshwatertobreed.Everyyear,duringJulyandAugust,thebreedingsturgeonmigratesfromtheestuaryoftheYangtzeRiverupstreamandcompletegonaddevelopmentthere.BetweenOctoberandNovemberofthefollowingyear,theytraveltoaspecificareaintheupperandmiddlereachesoftheYangtzeRivertospawn.Thefemalesturgeonleavesrightafterthespawnwhilethemalestaysuntiltheendofthebreedingseason.Aftertheeggshatch,thebabysturgeonsswimtothesurfaceofthewateranddriftsalongthecurrents.Threetosevendayslater,theydivetoforageforfoodatthebottomoftheriverandstayindeepgroovesthereforthewinter.ThebabysturgeoncanbefoundattheestuaryoftheYangtzeRiverbetweenAprilandOctoberinthenextyear,wheretheypasstheiradaptivephase.Theyarereadytoentertheoceanwhentheirlengthexceeds30cm.Thetotalmigrationandbreedingcycletakes18months,coveringaround3,000km,thelongestamongalltheanadromousfishesintheYangtzeRiver.
ChinesesturgeondatesbacktotheCretaceousperiod,andisknownasamemberoftheChondrosteigroup,atransitionbetweenChondrichthyesandOsteichthyes.Theancientfishhasasturdyandelongatedbody,acuminatedbutbluntlypointedsnoutandfourbarbelswhichdescendfromthesnoutnearthefrontofthemouth.Thereareplumblossomshapedpatternsonthesnoutofthesturgeonwhileitsbodyiscoveredwithfiverowsofthickbonyscutes,oneontheback,twooneachside.Thenumberofscutesdiffersamongindividuals.Normally,thereare12-14bigoneslooselyarrangedontheback.
Chinesesturgeongrowfast,andcanreachenormoussizes.Theone-yearold鈥檚incultivationsweigharoundtwokg,whilewildonesgaineightto14.5kgbyaverageeveryyear.Anaveragematuredmalesturgeonis250cmlongandweighs150kgwhilethefemalereaches400cmlongandweighsmorethan350kg.Thelargesteverfoundis700kg.
ThebottomoftheriversandseasisthemainareainhabitedbyChinesesturgeon.Babysturgeonsfeedonplantsandinvertebratesunderwater.Havingasharpsenseofsmelllikeadog,Chinesesturgeonareexpertsinhuntingforsmallfishandshellshiddeninsand.
Chinesesturgeoncanliveaslongas50years.Howevertheymaturequitelate,11yearsforthemaleand14yearsforthefemale,andtheyonlyspawneverythreetofiveyears.Whatmakesthecaseevenworseisthatthesurvivalrateisverylow.
In1988,Chinesesturgeonwaslistedamongthefirst-classprotectedanimalsinChina.In1997,itwasrecognizedasanendangeredspeciesbytheConventiononInternationalTradeinEndangeredSpecies(CITES).Andin2010,itenteredtheInternationalUnionforConservationofNature(IUCN)RedListofCriticallyEndangeredSpecies.
InChina,artificialbreedingofChinesesturgeonhasbeeninoperation,withmorethansixmillionfryreleasedintotheYangtzeRiversofar.However,thenumberofwildChinesesturgeoncapableofbreedingislessthan100.TherarityofChinesesturgeongainedthefishanickname鈥攁quaticpanda.
TheChinesegovernmenthasbeenworkingonsavingtheindigenoussturgeonsincethe1970s.Atthattime,therewerethousandsofsturgeonintheYangtzeRiver,morethan19spawninggroundsinthelowerJinshaRiverandtheupperreachesoftheYangtzeRiver.However,waterconservancyprojects,overfishing,pollution,andheavyshippingtraffichavepushedthespeciestothevergeofextinction.
Enteringthenewcentury,thegovernmentimposedaseasonalfishingbanintheYangtzeRiverandapermanentfishingbanforwildChinesesturgeon,alongwithcampaignsforraisingpeople鈥檚awarenessfortheirprotection.Afterabsenceofsignsofnaturalbreedingfortwoyears,in2015,babyChinesesturgeonwerediscoveredonceagainintheestuaryoftheYangtzeRiver,whichindicatesthesturgeonhavefoundtheirnewspawninggrounds.InSeptember2017,anadultwildChinesesturgeonabout180cminlengthandweighingaround100kgwasfoundupstreamoftheYangtzeRiver.Luckily,thisgiantcreaturewasn鈥檛hurtintheprocessofbeingcaught,andwasimmediatelyre锛峫easedbackintothewater.C
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