Diseases have been known  to occur among fishes from time immemoria

Sawant, B T

Sawant, Paramita Banerjee

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Osrrlotic prcssu rc  : The osnlotic pres- T c m p c r a t t ~ r e  : Each fisll sl,ccics has I-lowcvcr. scictitific quest to uridcrstarid surc ofl)urc \\.nrcr C S C ~ ~ S  a force on living 311 illhcrcnt tcrlipcraturc rarlgc w i ( l l i r l  tllc causcs ofdiscascs ;~rllor~g fisl~cs.   rid C C I I S  C C ~ I I ; I ~  to ollc ntr1losl)hcrc. \\.'~~cII a \vhicll i t  c;y <urvi\,c. _cro\r. alld I.cl)roducc. ;~ttci~ll>ts lo co~ltroi thrni g:~iricd strcrlgtl~ li\,irlg cell IS in a quality walcr c11viro11- Nutur:~] \\a[cr \vllicll stlr)l)orls fisll lift orily during the I;tst two-tliirds of?()"' ccn- I I~CII! .  I I I C I C  is ;I liiglicr osrnotic prcssurc gcncrally has a rarigc of tempcraturc tury. L;frorts to cure fisl~ d~sc ;~scs  rcquir-c irisi~ic tlic cell tliari outsidc. Thc scn~i-  lar to rcquircrncnts oftllc fist1 spccics l i v -  a sornc\rfliat diff'crcnt nppro;~cll corill~arcd ~>criiic;rhlc cell membrane may allow somc ins thcrc. Ctiangcs in cr~vironriicntal tcni- to mc;lsurcs ;~cfol,tctl ro con11)at or dc;~l  su[~sl;lrlees \v i th i r l  l h ~  10 diffuse out, pcraturcs beyond t)le nor-rilal sur\,ival tvitll ciiscnscs anlong tcrrcstri;~l ;~niriinls. l)ul [Ilc yr c;~tcst cfl>ct is in rcspcct of  range of fishcs may cnusc tlicmi~l traLtma. -1'lic reason 'is tIi;tt li1.c aquatic ;~riirii;lls . d~f'fi~siori of \%.;ltcr irito tfic C C ~ I  to cqual- Disorders 111 f i ~ t : ~ ~  arisirlg fionl thcrnlnl li\,c i r ~  ari critircly diflkrcrlt crivirorlr~icri! I/.C osrllotic pressures. l'hc rcsult is a trauma include cffccts on [hc ~ a r d i 0 - v ; ~ ~ -  '( Factors a l lhe  e~iviron,nrnt sircli ;IS \v:1- floodirig of  tlic cell, ol'le~i until i t  brusts. cular systcnl, the nervous sysrcrll, tcr tcriiprr~turc, pll, dis~oI\~cd C ; I S ~ S .  ;irld otllcrs come into play in the st;itc of'pr-o- Sutjccting the fish to cxtcmal osniotic changcs in colloidal statc ofprotcins and liferation of discasc causirig or_cnrlisrlis prcssuics \vliich niay hnppcn to be lower rcduction or ccssatio!~ of cnzyriiatic ac- and rhcir influcncc in causing discnsc tllnn tllc osmotic prcssurc of the entire tivities. Thcnllal traur'la may rcsu't i n  among fishes. fish tcrlds to diffuse out substances from pcnnancnt inlpairrllcnt of body functioris or hcalth. i3roadly statcd, thc incidcncc of  dis- \ v i ' l l i r l  eel's. ::I: r:; '::\c ififfcrcn! causes such as TllcqLr~lit\ofa \vnrcr in \vhich fishcs of  fish lo nutritional disorders. genetic disorders, live i l l  rlnture or tllc u.atcr in  which they 'c"'Pcra[ure is "ariablc. I t  depends not physical injuries, CO-existing org;lriisms ;Ire plnccd 10 live 111~s~ tlavc such an 0s- Orl the environment in utl ici l  the?' (agcnts) and ncgativc cffccts due to non- niotic pressure that cnablcs the been l iv ing but  a l so  O n  Ihc  living cnritics such as critical i~itcnsitics n;lricc o f a  r e l n t i v c l y  llamow range ofos- ofthe change. Thc duration of tcmpcra- ofabiotic cnvironmcntal factors and rlatu- pressure i n  the c c i l  structure ofthc tureextremes prevailing in thcircnviron- ral or man-made pollutants, including poi- fjstlcs so as to maintain the cclluIar water me"[ is also important During cmbry- sonous substances. and salt therc in  a nianncr that would pre- onic development, marked temperature Whcncvcr conducive cnvirorinlcrlta] vcnr cells froril collapsrng. Another im- fluctuations from the optimum could lcnd linlits arc crossed csccssivc altcratiorl portant factor relating to osniotic pres- to abnormalities (malformations of the fins, gill covers and scalcs, anomalics in  in thcsc linlits takc placc physiological surc and fish survival involvcs ova. Eggs and biochemical changcs occur wittiin rclcased by fcnialc frcshwater fishcs are the vcrtcbral column ctc.). tlic fish, \r.hich arc often bcyorid thcir flaccid and must absorb water (water Ttic process of thermal adaptation is ability to sun~ivc. Thc fish arc either killed hardcriirlg). Eggs of frcshwater fishes largely an enzymc - nicdiatcd mechanism. as a dircct rcsult of thc physical alter- subjected to \vatcr wilt1 a relatively high Adaptation to cold condition is mani- ation, or thcir systems arc damaged to saliriity cannot absorb uatcr against thc fcitcd in the biosynthcsis of  ncw \sari- thc point whcrc they bcconlc vulncrablc. rclativcly high osniotic pressurc within ants of cnzyrnc proteins. ~ lycogcn and to other discases. thc egg and thcrcforc die froni thc effccl. fats, which arc bcttcr suited for catalysis Thc most common diseascs of fishes Diasnosis of adverse effects of os- at low temperatures. Mortality due to rclatcd to physical factors arc associatcd rnotic prcssurc on fishcs is difficult. lcthal conditions o i  hcat and cold is rc- with osnlotic prcssurc, cnvironrnental I-rcsh\vater fistics sut?lectcd to high sa- lated to the inactivation of the cnzymcs. tcnlysr3t~:rc. hydrogen ion corlccrltration linity conccntrarions bcconi: lethargic, The visible effccts associatcd wrrh i pH i ;inti d~ssolvcd air. These factors,arc seek the shore arcas of  ~ I I C  pond or may insufiicient adaptation are various. Vcry often disregarded as causcs of diseases even attcriipt to I!=ave the water. Analy- high temperatures affect thc fish, cspc- in fishcs. But when thcsc factors niovc sis of water for total dissolved solids, cially when the oxygcn conccntrations beyond critical limits. thc effccts can be salir~ity ctc., may indicatc ranges toler- are inadequate. Undcr such conditions. 

Environmental stress induced fish diseases

http://eprints.cmfri.org.in/6256/1/632.pdf

Environmental stress induced fish diseases

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