MATERIAL AND GENERAL EXPERIMENTAL
PROCEDURES
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Oalotelphwa WK
(Fahriai*»s) is M
aaonnirt wily i^ortant fpaahifstar fitld ayah with great
oannarclal raina unsi |j| ahondant
mi
%na ant g^f ■%§ of
Mflitpir* fhiM araba Ut« in IwraM la thi p«Mr PitUi
«& tank tads and lira alnsa to tha waters alga* inoidns
their wide arillaldUtjr and ooaweraial iaportMice« oraba
are vary eaay to eollaat# handle, and Maintain in Un
1 abnratnrvi Thar M*a knotat to hart a good adarnimiitr
to laboratory eonditiona In general and woora to to idaal
tap art amt <1 nodal in toadeity studies in partieular*
Biology of Qaialalptaa oanan aanax
Since this investigation la of an aaopfayalolagloal
nature, a brief aeeount of tha biology of tha orab inrolvad
in thia imreetigaticM nyr provide a good preaefele to this
stay* fha iTadtatar* fiald «rab 2p ms IMI (fahaiaitaa)
mnan is wenoorsy snow# mi *||«SSkhBhmm£I J9BSQBHQShI %noroat/§
la a daotad nmnbaeean namaUy f
tha pai^r
e*d Irrigating af*»*ia of apra** India*
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¥&• irate 4c amphibious and reproduae 4a freeh»
wetter*
further It liras 4a partial!/ water fined
teurrowa and to stele to dlsefiaemate depth and diataaoe
with groat praaislon (somaeefchar A Al*» ISBl)* It 4a
carnivorous feeding oa worms* Insects ate*, and oceans! cn ally
4t teicciaaa sannltealiatle feeding oa young crates*
& ACBSX AMS ssahihits my good tolerance to aoaMRtratieas
sac water without say apparent 111 effects (Rasumurthy, l9H)t
the pollution of freshwater eariroaaent is terowght out das to
postioidos meetly through the aariol apraylag to the appli~
cation of peddf fielde and pcoda* This nay cause physiolo­
gical damage to tho crates* This freshwater field arete la
selected as the ideal experimental animal far this iaresft4»
Cation* which ere delicious in South India* and is called as
*Poor men* s Protein* • Thus tey this wirtus of its
carnivorous feeding hateits* easy cyailahillty* edsptatellity
to wsriod amrl rfau»ntal conditions*
the present Investigation deals with the eoaparitiv*
evaluation of toxlelty of two different organophosphorous
pesticides like malathlon md methyl parsthioo#
the
commercial grads maietteiott and methyl parathloa ware
purchased from tho looal fertiliser stares*
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JHUtiHttfll
Dm toawarolal indt aalathion (<W) dtoethyl
diethyl aaetepte Mociltilt) kadUtyg a
mhw of a oifan^te^terouf lately has tha aapCtolaJ
Ittuftt Cjgllj^gp&g* It is a slear krona to aolourless
liquid nith aareaptan Ukt adotarst aldda in watar
approxtoataly 1*5 ppa act &*c9 ooaplataly mMU to aoak
•starat high aroaatie solveaka and katanas# poorly solatia
in «u«hiAi< hntrn narton m
MaXathlon la ana of too safaet
toaaaiialdasf tor It has to seats oral UO^ to rata
900 * 9600 *g/kg (Metstotoa# I99t)«
Methyl parathlon
tka aaaaaarcial grate natty! parethlaa (0-0
dtoethy! o-D-aitrophaayl pteaterottoiti) la alaa a
aaakar of tka argtoopheaphei'eus Fately taw tka eapidrtoal
formal*
It la akplf a dtoethyt analogue af
parathlon# la a light hrowt to colourless liquid# eolUhla
lit orgaikla solvent# unlike nalathion# nathyl partition
kaa to asato oral
to rata of It m/hg vhisfa aeons it la
highly tatea than —etf|h|*wi#
Beth too versatile organophaaphaTotta tosaetlcldee
widely tote throughout tha world to matral orep peats# fllaa
tod nosqultoes kaaauaa they art hio«»dagrteahle and neo-parslatant
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insecticide (Fisfeher* 1966§ Alien* 1966* Boefchount j| j^f
1977) and their entry late the aquatic eurironaunt
cmuw
greet haroe to the aquatic organims including enti and
fishes (Darsie and Corrida*, 195i§ Nolle* 19*1*
Baehanohideen and Subbe Nee* 19B2§ Bash anoh* dean and
Pervatl* 19Bt). In the tier of the eeer arallablllty and
vtreatallty of these pesticides end their deleterious
offsets on crabs* aala&hlon and nathyl parathion are
sheeted so the ideal pollutants to sake a eosparatise
evaluation of their twddt/ on male individuals of
tn*mUr (laid «nk gUrtfliaaBt MBg MBg-
Malntalamos of c»erlaental anlnals
uaMMHOiueaMnuMMftMaManaMaaMniMaHaHMHMeMOMnMMMwaiMMHMes
the erahs ears oellooted fron the leeal paddy
fields* brought to the laboratory and kept la glass aquaria
with water just enough to nbnsrge half of the body of the
crabs*
Mortality was great in the first few days till the
srahs has bsosna adjusted to laboratory conditions* The
water in the aquaria was
daily to preside freeh»
miter rich in osygan* the crabs were fed daily with
earthMoras and frog nusolea* and the erahs wore loft for a
week sojourn for adapting to laboratory conditions before
foi> »?qHirin«ntatil on ■
In order to
uHfortmity
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in oapcsiaaiitaX analysis only male crabs* Th* tenperstur®
la th* aquaria ms tlPc ♦ X°C and th* hbc is aaintaiiiod
throng)i cut th* sours* of ®jq?erin«ntatian. For *11 the
nswliwia purpo *•*» the only aele orshe weighing l$|^2(
Mfc taken.
Eaperiiunt of th® present iavestigetion, is
conducted la ilslia islir awndition* as suggested If
&«**«£f ffr
(I9SL).
latesss.
Factors like flow of water* twperature, salinity*
pH, hardness of water ste» which ar® likely to contribute
variation* la toxLoity wort nullified to s satisfactory
lord (suUlcarl, 1977# Ubnberg aid theedr* 1979|
Qiakouaakos j$ j&«t 1579* Parvati, 19B2). Th* crabs vara
starved for 2b tors prior to aaah ostiaatloa so as to
allsdnat* th* possibility of aay dietary influane*. As
dotriflcatiaa and actdolisn of senobioties in lidos is
laflasaood by bolding la captivity (D*waide* 1972) groatsr
car# was token in aoiatatnano* and the crabs am handled
varv sMttlr md aarefuUv*
wr **Pie
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