crotalus is a genus of venomous pit vipers found only in the americas from southern canada to northern argentina , colloquially known as rattlesnakes .

the name is derived from the greek word κρόταλον krótalοn , which means " rattle " or " castanet " , and refers to the rattle on the end of the tail which makes this group ( genera crotalus and sistrurus ) so distinctive .

currently , 32 species are recognized .

crotalus

crotalus viridis viridis ( rafinesque 1818 ) crotalinus viridis rafinesque 1818 crotalus viridis viridis — klauber 1936 crotalus viridis viridis — klauber 1952 : 103 crotalus viridis viridis — stebbins 1985 : 231 crotalus viridis viridis — liner 1994 crotalus viridis viridis — conant & collins 1991 : 236 crotalus viridis — mcdiarmid , campbell & touré 1999 : 297 crotalus viridis viridis — tennant & bartlett 2000 : 529 crotalus viridis viridis — ashton et al . 2001 crotalus viridis viridis — campbell & lamar 2004 crotalus viridis — hoser 2009 crotalus viridis — crother et al . 2012 crotalus viridis — wallach et al . 2014 : 196 crotalus viridis — davis et al . 2016 crotalus viridis nuntius klauber 1935 crotalus confluentus nuntius klauber 1935 crotalus viridis nuntius — klauber 1936 crotalus viridis nuntius — stebbins 1985 : 232 crotalus viridis nuntius — crother 2000 : 60 crotalus viridis nuntius — ashton et al . 2001 crotalus viridis nuntius — campbell & lamar 2004 crotalus viridis — beaman & hayes 2008 crotalus viridis nuntius — lillywhite 2014 : 23 crotalus viridis nuntius — davis et al . 2016
5 . blue : crotalus oreganus helleri southern pacific rattlesnake 6 . orange : crotalus oreganus lutosus great basin rattlesnake 7 . red : crotalus oreganus oreganus northern pacific rattlesnake
snake venomics of the central american rattlesnake crotalus simus and the south american crotalus durissus complex points to neurotoxicity as an adaptive paedomorphic trend along crotalus dispersal in south america .
2 . red : crotalus cerastes cerastes - mohave desert sidewinder 3 . orange : crotalus cerastes laterorepens - colorado desert sidewinder
snake venomics of the central american rattlesnake crotalus simus and the south american crotalus durissus complex points to neurotoxicity as an ad . . . - pubmed - ncbi
goldberg , s . 1999 . reproduction in the blacktail rattlesnake , crotalus molossus .
notes on identifying subspecies of western rattlesnakes , crotalus oreganus , found in california .
crotalus is available under the mit license . see the license file for more info .
geographic and ontogenic variation in venom of the western diamondback rattlesnake ( crotalus atrox ) .
phenotypic integration in the feeding system of the eastern diamondback rattlesnake ( crotalus adamanteus ) .
click the banners below to learn more about these fascinating members of the genus crotalus .
patrick leary changed the thumbnail image of
file : crotalus . cerastes . jpg
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mackessy , stephen p . 1991 . literature : venom ontogeny in the pacific rattlesnake crotalus viridis helleri and crotalus viridis oreganus . litteratura serpentium 11 ( 5 ) : 116 - get paper here
aldridge , r . 1979 . female reproductive cycles of the snakes arizona elegans and crotalus viridis .
diller , l . 1990 . a field observation on the feeding behavior of crotalus viridis lutosus .
abby greb added text to
brief summary
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crotalus cerastes hallowell , 1854
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timber rattlesnakes ( crotalus horridus ) use chemical cues to select ambush sites . - pubmed - ncbi
crotalus is available through cocoapods . to install it , simply add the following line to your podfile :
beaupre , s . 1993 . an ecological study of oxygen - consumption in the mottled rock rattlesnake , crotalus - lepidus - lepidus , and the black - tailed rattlesnake , crotalus - molossus - molossus .
charland , b . 1989 . size and winter survivorship in neonatal western rattlesnakes ( crotalus viridis ) .
kento furui added the japanese common name
ヨコバイガラガラヘビ
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crotalus cerastes hallowell , 1854
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ontogeny of striking , prey - handling and envenomation behavior of prairie rattlesnakes ( crotalus v . viridis )
home range and behavior of the timber rattlesnake ( crotalus horridus )
by jennifer p . adams
hemorrhagic toxins from rattlesnake ( crotalus atrox ) venom . pathogenesis of hemorrhage induced by three purified toxins .
from crotalus durissus terrificus showed antiviral activity against dengue and yellow fever viruses . toxicon 59 : 507–515 .
means , b . 2009 . effects of rattlesnake roundups on the eastern diamondback rattlesnake ( crotalus adamanteus ) .
graves , b . 1989 . defensive behavior of female prairie rattlesnakes ( crotalus viridis ) changes after parturition .
geographic and ontogenic variation in venom of the western diamondback rattlesnake ( crotalus atrox ) . - pubmed - ncbi
renato agazzi added the italian common name
crotalo ceraste
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crotalus cerastes hallowell , 1854
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amy chang selected
geographic range
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crotalus cerastes hallowell , 1854
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phenotypic integration in the feeding system of the eastern diamondback rattlesnake ( crotalus adamanteus ) . - pubmed - ncbi
macartney , m . 1989 . diet of the northern pacific rattlesnake , crotalus viridis oreganus , in british columbia .
sealy , j . b . 1996 . serpentes : crotalus horridus ( timber rattlesnake ) mating . herpetological review .
ontogeny of striking , prey - handling and envenomation behavior of prairie rattlesnakes ( crotalus v . viridis ) - sciencedirect
( crotalus viridis viridis , ) . paper presented at meeting of the animal behavior society , tucson , az .
cameron dl , tu at . characterization of myotoxin a from the venom of prairie rattlesnake ( crotalus viridis viridis ) .
natureserve explorer , 2004 .
crotalus molossus
( on - line ) . accessed july 06 , 2004 at urltoken .
exploring the venom proteome of the western diamondback rattlesnake , crotalus atrox , via snake venomics and combinatorial peptide ligand library approaches .
macartney , m . , p . gregory . 1988 . reproductive biology of female rattlesnakes ( crotalus viridis ) in british columbia .
weima , andré 1992 . crotalus durissus vegrandis in captivity . litteratura serpentium 12 ( 5 ) : 81 - 85 - get paper here
widmer , e . 1967 . helminth parasites of the prairie rattlesnake , crotalus viridis rafinesque , 1808 , in weld county , colorado .
petricevich vl , mendonça rz ( 2003 ) inhibitory potential of crotalus durissus terrificus venom on measles virus growth . toxicon 42 : 143–153 .
cosewic . cosewic assessment and status report on the prairie rattlesnake crotalus viridis in canada . none . ottawa , canada : cosewic . 2015 .
geographical distribution of crotalus durissus with stomach contents from central region of brazil covering forest formations of amazon and atlantic forest , caatinga and cerrado .
food composition in individual males , females , newborns and juveniles of crotalus durissus from central region of brazil ( n = 30 snakes ) .
s1 text . the concatenation and analysis of mitochondrial dna for the crotalus viridis complex , with best - supported models of sequence evolution provided .
mccranie j r 1993 . crotalus durissus linnaeus , neotropical rattlesnake . catalogue of american amphibians and reptiles 577 : 1 - 11 - get paper here
crotalus is an convenient and fast approach to create attributedstring in swift . this library is inspired by colorize which is a ruby gem colorize string .
cameron , d . , a . tu . 1977 . characterization of myotoxin a from the venom of prairie rattlesnake ( crotalus viridis viridis ) .
charland , b . , p . gregory . 1990 . the influence of female reproductive status on thermoregulation in a viviparous snake , crotalus viridis .
duvall , d . , g . shuett . 1997 . straight - line movement and competitive mate searching in prairie rattlesnakes , crotalus viridis viridis .
hayes , w . 1992 . prey - handling and envenomation strategies of prairie rattlesnakes ( crotalus v . viridis ) feeding on mice and sparrows .
benício , r . a . 2016 . crotalus durissus ( south american rattlesnake ) arboreal habitat use . herpetological review 47 ( 3 ) : 477 .
mccranie j r 1984 . crotalus vegrandis klauber . uracoan rattlesnake . catalogue of american amphibians and reptiles ( 350 : 1 - 2 - get paper here
winchell , s . 2007 . klapperschlangen ! die gattung crotalus . reptilia ( münster ) 12 ( 66 ) : 18 - 25 - get paper here
kardong , k . , k . rochelle . 1996 . mechanical damage inflicted by fangs on prey during predatory strikes by rattlesnakes , crotalus viridis oreganus .
sweet , s . 1985 . geographic variation , convergent crypsis and mimicry in gopher snakes ( pituophis melanoleucus ) and western rattlesnakes ( crotalus viridis ) .
description of the gamonts of a small species of hepatozoon sp . ( apicomplexa , hepatozoidae ) found in crotalus durissus terrificus ( serpentes , viperidae ) .
echeverrigaray , s . , grazziotin , g . , grazziotin , f . & agostini , g . 2000 . random amplified polymorphisms between two south american subspecies of rattlesnakes ( crotalus durissus collilineatus e crotalus durissus terrificus ) . braz . arch . biol . techn . 313 - 317 . [ links ]
quinn hr . morphology , isozymes , and mitochondrial dna as systematic indicators in crotalus : ph . d . dissertation . university of houston ; 1987 .
latella , ian m . and howard snell . 2015 . geographic distribution : crotalus viridis ( prairie rattlesnake ) . herpetological review 46 ( 1 ) : 62
warning , nathanial and nora covy . 2016 . crotalus viridis ( prairie rattlesnake ) behavior / long distance swimming . herpetological review 47 ( 1 ) : 145
due to some unique rules for the triduum , if you attend triduum liturgies , you may hear one of the rarest of liturgical instruments : the crotalus .
ownby cl , cameron d , tu at . isolation of myotoxic component from rattlesnake ( crotalus viridis viridis ) venom . electron microscopic analysis of muscle damage .
exploring the venom proteome of the western diamondback rattlesnake , crotalus atrox , via snake venomics and combinatorial peptide ligand library ap . . . - pubmed - ncbi
s1 fig . plots depicting bayesian posterior probabilities that stem from assigning specimens to subspecies under equal prior probabilities in the western rattlesnake ( crotalus viridis ) complex .
taylor , nathan caleb and sean p . graham . 2015 . geographic distribution : crotalus viridis ( prairie rattlesnake ) . herpetological review 46 ( 4 ) : 572
william , p . , b . william . 1974 . mortality and weight changes of great basin rattlesnakes ( crotalus viridis ) at a hibernaculum in northern utah .
we have tried to account for most of the main species of the crotalus family below . this list is arranged alphabetically by scientific name ( species extension ) .
chepsongol , roxanne m . and douglas w . burkett . 2013 . crotalus viridis ( prairie rattlesnake ) diet . herpetological review 44 ( 3 ) : 520 - 521
butler , j . , t . hull , r . franz . 1995 . neonate aggregations and maternal attendance of young in the eastern diamondback rattlesnake , crotalus adamanteus .
macartney , m . , p . gregory , b . charland . 1990 . growth and sexual maturity of the western rattlesnake , crotalus viridis , in british columbia .
gibbons , j . w . 1972 . reproduction , growth and sexual dimorphism in the canebrake rattlesnake ( crotalus horridus atricaudatus ) . copeia 1972 : 222 - 226 .
food item , ameiva ameiva , recorded in the stomach of a female crotalus durissus . specimen deposited in the coleção herpetológica da universidade de brasília ( chunb 49673 ) .
gloyd , howard k . , 1978 . the rattlesnakes : genera sistrurus and crotalus . society for the study of amphibians and reptiles , kansas . pg . 204 .
the term “crotalus” is a latin term that comes from the greek word “krotalon” ( κροταλον ) , which means “rattle . ” ( as a result , “crotalus” is also the name of a genus of rattlesnakes . ) crotaluses can come in many different designs ( see the pictures and videos at the end of this article for examples ) .
hellebuyck , tom 2012 . captive breeding characteristics of the uracoan rattlesnake ( crotalus durissus vegrandis ) . litteratura serpentium 32 ( 4 ) : 181 - 186 - get paper here
kauffeld , carl f . ; gloyd , howard k . 1939 . notes on the aruba rattlesnake , crotalus unicolor . herpetologica 1 : 156 - 160 - get paper here
mccranie j r 1986 . crotalus unicolor van lidth de jeude . aruba island rattlesnake . catalogue of american amphibians and reptiles ( 389 : 1 - 2 - get paper here
to cite this page : desai , m . 2004 .
crotalus molossus
( on - line ) , animal diversity web . accessed july 09 , 2018 at urltoken
to cite this page : johnson , l . 2018 .
crotalus adamanteus
( on - line ) , animal diversity web . accessed july 09 , 2018 at urltoken
to cite this page : russell , h . 2017 .
crotalus viridis
( on - line ) , animal diversity web . accessed july 09 , 2018 at urltoken
to cite this page : falk , a . 2002 .
crotalus horridus
( on - line ) , animal diversity web . accessed july 09 , 2018 at urltoken
clark , r . w . 2002 . diet of the timber rattlesnake crotalus horridus . j . herpetol . 36 ( 3 ) : 494 - 499 . [ links ]
to cite this page : ingmarsson , l . 2002 .
crotalus atrox
( on - line ) , animal diversity web . accessed july 09 , 2018 at urltoken
travaglia cardoso , silvia r . and ana c . parpinelli 2006 . crotalus durissus terrificus . a case of xanthism . herpetological bulletin 97 : 38 - 39 - get paper here
enderson , e . f . 2010 . the occurrence of crotalus viridis in sonora , mexico . sonoran herpetologist 23 ( 7 ) : 94 - 96 . - get paper here
description of the gamonts of a small species of hepatozoon sp . ( apicomplexa , hepatozoidae ) found in crotalus durissus terrificus ( serpentes , viper . . . - pubmed - ncbi
adams , jennifer p . ,
home range and behavior of the timber rattlesnake ( crotalus horridus )
( 2005 ) . theses , dissertations and capstones . 26 . urltoken
on the other hand , crotalus venom causes a persistent albuminuria and extensive tubular degeneration and cast formation , with death , preceded by great emaciation , after five to six weeks .
aeberhard , r . 2010 . interessante beobachtungen zur tragzeit der tropischen klapperschlange , crotalus durissus durissus . reptilia ( münster ) 15 ( 81 ) : 7 - 9 - get paper here
gloyd , howard k . 1936 . the status of crotalus unicolor van lidth de jeude and icrotalus pulvis ditmars . herpetologica 1 ( 2 ) : 65 - 68 - get paper here
hansen , r . w . & bryson , r . w . , jr . 2018 . crotalus viridis ( prairie rattlesnake ) diet . herpetological review 49 : 128 - 129 .
rokyta , d . , a . lemmon , m . margres , k . aronow . 2012 . the venom - gland transcriptome of the eastern diamondback rattlesnake ( crotalus adamanteus ) .
ferrante , lucas , rafael menegucci and ibere farina machado . 2015 . crotalus durissus ( south american rattlesnake ) swimming behavior to cross geographical barrier . herpetological review 46 ( 4 ) : 640
olivier , r . 2008 . grote verwarring rond een ‘kleine’ ratelslang : de hopiratelslang , crotalus viridis nuntius . lacerta 66 ( 1 - 3 ) : 40 - 46 - get paper here
golan , l . , c . radcliffe , t . miller , b . o ' connell , d . chiszar . 1982 . trailing behavior in prairie rattlesnakes ( crotalus viridis ) .
macias - rodriguez , eduardo f . , ana gatica - colima and hector gadsden . 2013 . crotalus viridis ( prairie rattlesnake ) reproduction / combat . herpetological review 44 ( 3 ) : 521
hammerson , g . 2007 .
crotalus adamanteus
( on - line ) . the iucn red list of threatened species 2007 e . t64308a12762249 . accessed november 02 , 2017 at urltoken .
chiszar , d . , k . scudder , l . knight , h . smith . 1978 . exploratory behavior in prairie rattlesnakes ( crotalus viridis ) and water moccasins ( agkistrodon piscivorus ) .
brown , w . s . 1993 . biology , status , and management of the timber rattlesnake ( crotalus horridus ) : a guide for conservation . ssar herp . circular no . 22 .
hoser , r . 2009 . a reclassification of the rattlesnakes ; species formerly exclusively referred to the genera crotalus and sistrurus . australasian j . herpetol . 3 : 1 - 21 - get paper here
rowley , paul 2003 . the development of a safe restraint method for handling adult specimens of the neotropical rattlesnake crotalus durissus . litteratura serpentium 23 ( 1 ) : 40 - 45 - get paper here
chiszar , d . , k . stimac , t . boyer . 1983 . effect of mouse odors on visually - induced and strike - induced chemosensory searching in prairie rattlesnakes ( crotalus viridis ) .
saviola , a . , d . pla , t . castoe , j . calvete , s . mackessy . 2015 . comparative venomics of the prairie rattlesnake ( crotalus viridis viridis ) from colorado .
macarthney , j . m . 1989 . diet of the northern pacific rattlesnake , crotalus viridis oreganus , in british columbia . herpetologica 45 ( 3 ) : 299 - 304 . urltoken [ links ]
santos , s . m . & germano , v . j . 1996 . crotalus durissus ( neotropical rattlesnake ) prey . herpetol . rev . 27 ( 3 ) : 143 . [ links ]
feoktistow , a . e . 1893 . on the physiology of the rattle of crotalus durissus . ann . mag . nat . hist . ( 6 ) 11 : 54 - 58 - get paper here
(
petition to list the eastern diamondback rattlesnake ( crotalus adamanteus ) as threatened under the endangered species act
, 2011 ; ernst and ernst , 2012 ; waldron , et al . , 2006 )
duvall , d . , d . chiszar , w . hayes , j . leonhardt , m . goode . 1990 . chemical and behavioral ecology of foraging in prairie rattlesnakes ( crotalus viridis viridis ) .
brown , william s . 1993 . biology , status , and management of the timber rattlesnake ( crotalus horridus ) : a guide for conservation . society for the study of amphibians and reptiles , oxford .
beaupre , s . j . 1995 . comparative ecology of the mottled rock rattlesnake , crotalus lepidus , in big ben national park . herpetologica 51 ( 1 ) : 45 - 56 . [ links ]
gatica - colima , ana , eduardo f . macias - rodríguez and ricardo paredes - león . 2014 . crotalus viridis viridis ( prairie rattlesnake ) ectoparasites . herpetological review 45 ( 1 ) : 143 - 144
macartney , j . malcolm & patrick t . gregory 1991 . literature : reproductive biology of female rattlesnakes ( crotalus viridis ) in british columbia . litteratura serpentium 11 ( 5 ) : 116 - get paper here
(
a status assessment and distribution model for the eastern diamondback rattlesnake ( crotalus adamanteus ) in georgia
, 2015 ;
florida ' s venomous snakes
, 2004 ;
petition to list the eastern diamondback rattlesnake ( crotalus adamanteus ) as threatened under the endangered species act
, 2011 ; ernst and ernst , 2012 ; hoss , et al . , 2010 ; steen , et al . , 2007 )
ownby , c . , t . colberg , g . odell . 1986 . in vivo ability of antimyotoxin a serum plus polyvalent ( crotalidae ) antivenom to neutralize prairie rattlesnake ( crotalus viridis viridis ) venom .
considering data to other viperids ( sawaya et al . 2008 ; marques et al . 2009 ; barbo et al . 2011 ) the frequency of individuals of crotalus durissus with prey in the stomach was low .
sandner - montilla f 1980 . una nueva especie del genero crotalus ( serpentes , crotalidae , crotalinae ) del sur del estado guarico , venezuela . memorias cientifica de ofidiologia ( no . 5 ) : 1 - 12
pifano , f . & rodriguez - acosta , a . 1996 . ecological niche and redescription of crotalus vegrandis ( serpentes : crotalidae ) in venezuela . brenesia 45 - 46 : 169 - 175 . [ links ]
davis m . morphometrics , molecular ecology and multivariate environmental niche define the evolutionary history of the western rattlesnake ( crotalus viridis ) complex . ph . d dissertation . university of illinois at urbana - champaign ; 2012 .
hampton pm , moon br . gape size , its morphological basis , and the validity of gape indices in western diamond - backed rattlesnake ( crotalus atrox ) . journal of morphology . 2013 ; 247 : 194–202 .
murphy et al . ( 1995 ) examined variation in mtdna , allozymes , and morphology of red diamond rattlesnakes and concluded that crotalus ruber and c . exsul should be considered a single species ( c . exsul ) with three subspecies ( c . e . exsul , c . e . ruber , and c . e . lorenzoensis . smith et al . ( 1998 ) applied to the iczn to conserve the name c rotalus ruber for the red diamond rattlesnake by giving the name crotalus ruber precedence over the name c . exsul . iczn ( 2000 ) gave crotalus ruber precedence over c . exsul whenever the two names are considered to be synonyms .
hoss , s . , c . guyer , l . smith , g . schuett . 2010 . multiscale influences of landscape composition and configuration on the spatial ecology of eastern diamond - backed rattlesnakes ( crotalus adamanteus ) .
hoyos , m . a . 2012 . a cascavel neotropical crotalus durissus : uma abordagem morfológica e da história natural em populações do brasil . tese de doutorado , universidade de são paulo , são paulo . [ links ]
the goal of the present work was to label crotalus durissus terrificus venom with 99m tc . the crude and labeled venom were then subjected to a hemolytic activity study to verify that labeling did not alter the biological activities .
crotalus is a genus of venomous pit vipers naturally occurring in the americas , from southern canada to northern argentina . the rattlesnakes currently found in south africa include the sidewinder ( crotalus cerastes ) , which is a desert ambush predator . members of this genus range in size from 50–60cm to over 150cm . most forms are easily recognised by the characteristic rattle on the end of their tails , although a few island populations are exceptions to this rule .
quijada - mascareñas & wüster , w . 2006 . crotalus durissus complex : from yucatan to patagonia : the natural history of the neotropical rattlesnake . reptilia ( gb ) ( 49 ) : 66 - 73 - get paper here
klauber , laurence m . 1935 . a new subspecies of crotalus confluentus , the prairie rattlesnake . transactions of the san diego society of natural history 8 ( 13 ) : 75 - 90 + 1 plate - get paper here
the orianne society . a status assessment and distribution model for the eastern diamondback rattlesnake ( crotalus adamanteus ) in georgia . none . clayton , georgia : the orianne society . 2015 . accessed september 10 , 2017 at urltoken .
sage , r . d . ; capredon , e . e . 1971 . la distribucion de la cascabel ( crotalus durissus terrificus ( laurentius ) en argentina y su significado zoogeographico . neotropica 17 ( 54 ) : 133 - 136
wüster , w . & bérnils , r . s . 2011 . on the generic classification of the rattlesnakes , with special reference to the neotropical crotalus durissus complex ( squamata : viperidae ) . zoologia 28 ( 4 ) : 417–419
graves , b . m . , m . b . king & d . duvall 1991 . literature : natural history of prairie rattlesnakes ( crotalus viridis viridis ) . litteratura serpentium 11 ( 1 ) : 24 - get paper here
justification : crotalus durissus has been assessed as least concern in view of its very wide distribution and its tolerance of a broad range of habitats . no specific threats have been reported and this species is not undergoing significant population declines .
shipley , b . , d . chiszar , k . fitzgerald , a . saviola . 2013 . spatial ecology of prairie rattlesnakes ( crotalus viridis ) associated with black - tailed prairie dog ( cynomys ludovicianus ) colonies in colorado .
trutnau , l . 2002 . bemerkungen zur verbreitung , biologie und taxonomie der tropischen klapperschlange crotalus durissus sowie zur pflege und zucht der unterart c . d . terrificus . herpetofauna 24 ( 140 ) : 13 - 24 - get paper here
the crotalus used to be universally used , but fell out of use in the last few decades . it seems , however , to have made a little bit of a comeback lately due to an increase of interest in traditional liturgy .
tozetti , a . m . , & martins , m . 2008 . habitat use by the south - american rattlesnake ( crotalus durissus ) in southeastern brazil . journal of natural history 42 : 1435 - 1444 . urltoken [ links ]
collection sites with voucher numbers of studied specimens of crotalus durissus and stomach contents from central region of brazil . chunb , coleção herpetológica da universidade de brasília ; ibsp , instituto butantan ; mzusp , museu de zoologia da universidade de são paulo .
(
petition to list the eastern diamondback rattlesnake ( crotalus adamanteus ) as threatened under the endangered species act
, 2011 ; gibbons and dorcas , 2005 ; hoss , et al . , 2010 ; steen , et al . , 2007 )
diller , l . v . & wallace , r . l . 1996 . comparative ecology of two snake species ( crotalus viridis and pituophis melanoleucus ) in southwestern idaho . herpetologica 52 ( 3 ) : 343 - 360 . urltoken [ links ]
the intravenous injection of crotalus atrox venom produces an immediate and profound fall in systemic arterial pressure . this change was observed in both cats and dogs , and it has been seen in previous experiments with rabbits , goats , guinea pigs and monkeys .
magres mj , wray kp , seavy m , mcgivern jj , sanader d , rokyta dr . phenotypic integration in the feeding system of the eastern diamondback rattlesnake ( crotalus adamanteus ) . molecular ecology . 2015 ; 24 : 3405–3420 . pmid : 25988233
frost , d . , g . hammerson , g . santos - barrera . 2007 .
crotalus viridis
( on - line ) . the iucn red list of threatened species 2007 : e . t64339a12771847 . accessed september 10 , 2017 at urltoken .
citation : davis ma , douglas mr , collyer ml , douglas me ( 2016 ) deconstructing a species - complex : geometric morphometric and molecular analyses define species in the western rattlesnake ( crotalus viridis ) . plos one 11 ( 1 ) : e0146166 . urltoken
harris , h . jr . , r . s . simmons 1976 . a new subspecies of crotalus durissus ( serpentes : crotalidae ) from the rupununisavana of southwestern guyana . mem . inst . butantan 40 / 41 : 305 - 311 . - get paper here
sant ' anna , s . & abe a . s . 2007 . diet of the rattlesnake crotalus durissus in southeastern brazil ( serpentes , viperidae ) . stud . neotrop . fauna e . 42 ( 3 ) : 169 - 174 . urltoken [ links ]
biological activity of the crotalus venom after the labeling process was assessed by indirect hemolytic activity . hemolytic activity of crude and labeled venom was assayed as described by cadillo et al ( cadillo et al , 1992 ) and activity was expressed as absorbance at 540 nm .
douglas me , douglas mr , schuett gw , porras lw . evolution of rattlesnakes ( viperidae ; crotalus ) in the warm deserts of western north america shaped by neogene vicariance and quaternary climate change . molecular ecology . 2006 ; 15 : 3353–3374 . pmid : 16968275
vanzolini , p . e . & calleffo , e . v . 2002 . a taxonomic bibliography of the south american snakes of the crotalus durissus complex ( serpentes , viperidae ) . anais da academia brasileira de ciências 74 ( 1 ) : 37–83 - get paper here
anderson cg , greenbaum e . phylogeography of northern populations of the black - tailed rattlesnake ( crotalus molossus , baird and girard , 1853 ) , with the revalidation of revalidation of c . ornatus , hallowell , 1854 . herpetological monographs . 2012 ; 26 : 19–57 .
gardiner , laura e . , christopher m . somers , dennilyn l . parker and ray g . poulin . 2015 . microhabitat selection by prairie rattlesnakes ( crotalus viridis ) at the northern extreme of their geographic range . journal of herpetology 49 ( 1 ) : 131 - 137
crotalus durissus terrificus ( south american rattlesnake ) venom possesses phospholipase a 2 activity , which can lead to hemolysis , and neurotoxic activity , both of which are also expressed by crotoxin . the biological activity evaluation showed that 99m tc labeling did not alter the activity of the cv .
(
cosewic assessment and status report on the prairie rattlesnake crotalus viridis in canada
, 2015 ; charland , 1989 ; chiszar , et al . , 1978 ; duvall , et al . , 1990 ; golan , et al . , 1982 ; zug and ernst , 2004 )
beaupre , s . j . , duvall , d . & o ' leile , j . 1998 . ontogenetic variation in growth and sexual size dimorphism in a central arizona population of the western diamondback rattlesnake ( crotalus atrox ) . copeia 1 : 40 - 47 . [ links ]
rudolph , d . craig ; schaefer , r . r . ; saenz , d . ; conner , r . n . 2004 . arboreal behavior in the timber rattlesnake , crotalus horridus , in eastern texas . texas journal of science . 56 ( 4 ) : 395 - 404 .
monteiro , h . s . a . ; silva , i . m . s . c . ; martins , a . m . c . and fonteles , m . c . ( 2001 ) , actions of crotalus durissus terrificus venom and crotoxin on the isolated rat kidney . ,
prigioni , carlos ; borteiro , claudio ; kolenc , francisco ; colina , marcelo ; gonzález , enrique m . 2013 . geographic distribution and apparent decline of crotalus durissus terrificus ( laurenti 1768 ; serpentes , viperidae ) in uruguay . cuadernos de herpetología 27 ( 2 ) : - get paper here
chiszar , david ; bryon k . shipley , hobart m . smith , kevin fitzgerald and anthony j . saviola . 2014 . straightness - of - path during and after vernal migration in prairie rattlesnakes , crotalus viridis , in eastern colorado . herpetology notes 7 : 425 - 436 - get paper here
the rattlesnakes of the genus crotalus evolved in north america and subsequently spread across central and south america ( echevarrigaray et al . 2000 ; quijada - mascareñas et al . 2007 ) . currently 41 species of crotalus are recognized , with greater a diversity in mexico and the united states ( uetz at al . 2016 ) . this genus is frequently considered as a model for studies related to ecology , due to its widespread distribution covering several habitats , including deserts , flooded areas , forest environments and open habitats ( norman , 1994 ; beaupre et al . 1998 ; place & abramson , 2004 ) .
depending on how you classify them , there are about 29 or 30 different species of rattlesnakes in the world . most of them fall within the crotalus family of snakes . of course , when you include the various sub - species found within each species , there are even more rattlesnakes to consider .
fill , j . , j . waldron , s . welch , m . martin , j . cantrell , s . bennett , w . kalinowsky , j . holloway , t . mousseau . 2015 . breeding and reproductive phenology of eastern diamond - backed rattlesnakes ( crotalus adamanteus ) in south carolina .
salomão , m . g . , almeida - santos , s . m . & puorto , g . 1995 . activity pattern of crotalus durissus ( viperidae , crotalinae ) : feeding , reproduction and snakebite . stud . neotrop . fauna e . 30 ( 2 ) : 101 - 106 [ links ]
vanzolini , p . e . 1947 . notas sobre um derodimo de crotalus durissus terrificus ( laur . ) nota nomenclaural sobre leimadophis almada ( wagler , 1824 ) ( = leimadophis almadensis auct . ) . papéis avulsos de zoologia ( são paulo ) 8 ( 24 ) : 273 - 283 - get paper here
ashton , kyle g . ; de queiroz , alan 2001 . molecular systematics of the western rattlesnake , crotalus viridis ( viperidae ) , with comments on the utility of the d - loop in phylogenetic studies of snakes . molecular phylogenetics and evolution 21 ( 2 ) : 176 - 189 . - get paper here
bauder , javan m . ; holly akenson , and charles r . peterson 2015 . movement patterns of prairie rattlesnakes ( crotalus v . viridis ) across a mountainous landscape in a designated wilderness area journal of herpetology sep 2015 , vol . 49 , no . 3 : 377 - 387 . - get paper here
davis ma , douglas mr , collyer ml , douglas me 2016 . deconstructing a species - complex : geometric morphometric and molecular analyses define species in the western rattlesnake ( crotalus viridis ) . plos one 11 ( 1 ) : e0146166 . doi : 10 . 1371 / journal . pone . 0146166 - get paper here
holycross , andrew t . ; thomas g . anton , michael e . douglas , and darrel r . frost 2008 . the type localities of sistrurus catenatus and crotalus viridis ( serpentes : viperidae ) , with the unraveling of a most unfortunate tangle of names . copeia 2008 ( 2 ) : 421–424 - get paper here
the western diamondback rattlesnake ( crotalus atrox ) is a heavy bodied snake with a triangular shaped head . there are two dark diagonal lines on each side of its face running from the eyes to its jaws . it has dark diamond - shaped patterns along is back . the tail has black and white bands just above the rattles .
marchi - salvador dp , corrêa lc , magro aj , oliveira cz , soares am , et al . ( 2008 ) insights into the role of oligomeric state on the biological activities of crotoxin : crystal structure of a tetrameric phospholipase a2 formed by two isoforms of crotoxin b from crotalus durissus terrificus venom . proteins 72 : 883–891 .
citation : muller vd , soares ro , dos santos - junior nn , trabuco ac , cintra ac , figueiredo lt , et al . ( 2014 ) phospholipase a 2 isolated from the venom of crotalus durissus terrificus inactivates dengue virus and other enveloped viruses by disrupting the viral envelope . plos one 9 ( 11 ) : e112351 . urltoken
wüster , wolfgang ; julia e . ferguson ; j . adrian quijada - mascareñas ; catharine e . pook ; maria da graça salomão < br / > and roger s . thorpe 2005 . tracing an invasion : landbridges , refugia , and the phylogeography of the neotropical rattlesnake ( serpentes : viperidae : crotalus durissus ) . molecular ecology 14 : 1095–1108
almeida - santos , selma maria ; maria da graca salomão ; elaine aparecida peneti , < br / > paulo sérgio de sena ; eduardo santos guimaraes 1999 . predatory combat and tail wrestling in hierarchical contests of the neotropical rattlesnake crotalus durissus terrificus ( serpentes : viperidae ) . amphibia - reptilia 20 ( 1 ) : 88 - 96 - get paper here
the south - american rattlesnake crotalus durissus , is restricted to south america ( campbell & lamar 2004 ) and has a discontinuous distribution ( wüster et al . 2005 ) from colombia to argentina ( vanzolini et al . 1980 ) . some populations exhibit considerable ecological variation , with closeby populations differing greatly from each other ( campbell & lamar , 2004 ) .
cozendey , p . , novelli , i . a . , do nascimento , a . a . , peters , v . m . & de sousa , b . m . 2017 . study of the renal sexual segment of crotalus durissus terrificus ( linnaeus , 1758 ) ( viperidae : crotalinae ) . herpetological review 48 ( 4 ) : 743 - 746
valencia - hernández , ángel alberto ; irene goyenechea < br / > & jesús martín castillo - cerón 2007 . notes on scutellation , length , and distribution of rattlesnakes ( serpentes : viperidade : crotalus ) in the state of hidalgo , mexico . acta zoológica mexicana ( n . s . ) 23 ( 3 ) : 29 - 33 - get paper here
davis , mark a . and michael e . douglas 2017 . prairie rattlesnake crotalus viridis ( rafinesque 1818 ) . in : rattlesnakes of arizona , volume i , 1st edition , editors : gordon w . schuett , martin j . feldner , charles f . smith , randall s . reiserer . eco publishing , pp . 289 - 332 - get paper here
a free - ranging specimen of crotalus durissus unicolor on aruba island was observed after striking rodent prey ( calomys hummelincki ) and after no - strike presentations . strike - induced chemosensory searching and trail following were seen after strikes . when a chemical trail was not present following a strike , the snake searched extensively near its refuge , but never emerged from it .
center for biological diversity , coastal plains institute , protecting all living species , one more generation . petition to list the eastern diamondback rattlesnake ( crotalus adamanteus ) as threatened under the endangered species act . none . usa : center for biological diversity , coastal plains institute , protecting all living species , one more generation . 2011 . accessed september 11 , 2017 at urltoken .
prival , d . b . , goode , m . j . , swann , d . e . , schwalbe , c . r . & schroff , m . j . 2002 . natural history of a northern population of twin - spotted rattlesnakes , crotalus pricei . j . herpetol . 36 ( 4 ) : 598 - 607 . urltoken ; 2 [ links ]
davis ma , douglas mr , webb ct , collyer ml , holycross at , painter cw , et al . nowhere to go but up : impacts of climate change on demographics of a short - range endemic ( crotalus willardi obscurus ) in the sky - islands of southwestern north america . plos - one . 2015 ; 10 ( 6 ) : e0131067 . pmid : 26114622
quijada - mascarenas , j . adrian ; ferguson , julia e . ; pook , catharine e . ; salomao , maria da graca ; thorpe , roger s . ; wuster , wolfgang 2007 . phylogeographic patterns of trans - amazonian vicariants and amazonian biogeography : the neotropical rattlesnake ( crotalus durissus complex ) as an example . journal of biogeography 34 ( 8 ) : 1296 - 1312
% 0 report % t arboreal behavior in the timber rattlesnake , crotalus horridus , in eastern texas % j texas journal of science . 56 ( 4 ) : 395 - 404 % a rudolph , d . craig % a schaefer , r . r . % a saenz , d . % a conner , r . n . % d 2004 % > urltoken % u urltoken citation
ty - rprt ti - arboreal behavior in the timber rattlesnake , crotalus horridus , in eastern texas au - rudolph , d . craig au - schaefer , r . r . au - saenz , d . au - conner , r . n . py - 2004 jo - texas journal of science . 56 ( 4 ) : 395 - 404 l1 - urltoken ur - urltoken er - citation
wüster , w . , ferguson , j . e . , quijada - mascareñas , j . a . , pook , c . e . & salomão , m . d . 2005 . tracing an invasion : landbridges , refugia , and the phylogeography of the neotropical rattlesnake ( serpentes : viperidae : crotalus durissus ) . mol . ecol . 14 ( 4 ) : 1095 - 1108 . urltoken [ links ]
holycross , a . t . , painter , c . w . , prival , d . v . , shawnn , d . e . , schroff , m . j . , edwards , t . & schwalbe , c . r . 2002 . diet of crotalus lepidus klauberi ( banded rock rattlesnake ) . j . herpetol . 36 ( 4 ) : 589 - 597 . urltoken ; 2 [ links ]
tecnécio - 99m tem sido o radioisótopo de escolha para procedimentos médicos e pesquisas experimentais . em decorrência de suas propriedades nucleares , 99m tc é adequado para detecção de alta eficiência com a vantagem do baixo risco radiológico . o veneno de crotalus ( cv ) apresentou propriedades antitumorais em estudos clínicos e estudos de biodistribuição são fundamentais em pesquisas clínicas . esse trabalho teve como objetivo obter um análogo de veneno de crotalus marcado com 99m tc que preservasse sua atividade biológica . após a marcação , a atividade biológica foi avaliada através do ensaio de atividade hemolítica . veneno nativo e marcado apresentaram atividade hemolítica indireta quando incubados em um meio contendo uma fonte exógena de lecitina . obteve - se um alto rendimento de marcação e a atividade biológica das moléculas foi preservada . nossos resultados sugerem que 99m tc - cv pode representar uma ferramenta muito útil para estudos de biodistribuição .
souza , kariny de ; rafael damasceno fernandes coelho , paulo mauricio almeida guimarães reis , patricia avello nicola , luiz cezar machado pereira and leonardo barros ribeiro . 2013 . predation of the spix’s yellow - toothed cavy , galea spixii ( rodentia : caviidae ) by the tropical rattlesnake crotalus durissus cascavella ( serpentes : viperidae ) in the semi - arid region of brazil . herpetology notes 6 : 277 - 279 . - get paper here
quijada - mascareñas , j . a . , ferguson , j . e . , pook , c . e . , salomão , m . g . , thorpe , r . s . & wüster , w . 2007 . phylogeographic patterns of trans - amazonian vicariants and amazonian biogeography : the neotropical rattlesnake ( crotalus durissus complex ) as an example . j . biogeogr . 34 : 1296 - 1312 . urltoken [ links ]
but , during this short period of time , is anything supposed to take its place ? that’s where the crotalus comes in . the church’s liturgical rubrics don’t prescribe a replacement for altar bells , but there is a long - standing tradition of using a wooden clapper or noise - maker in its place . this serves to both mark the same events as the altar bells , but in a less “sweet” way and thus maintain the somber tone .
@ misc { rudolph % 2c + d . + craig2004arboreal , title = { arboreal behavior in the timber rattlesnake , crotalus horridus , in eastern texas } , author = { rudolph , d . craig and schaefer , r . r . and saenz , d . and conner , r . n . } , journal = { texas journal of science . 56 ( 4 ) : 395 - 404 } , year = { 2004 } } citation
crotoxin ( crtx ) , the main proteic component of crotalus venom , displays cytotoxic activity against a variety of murine ( zwaal et al , 1975 ) and human ( corin et al , 1993 ) tumor cells in vitro . antitumor efficacy in vivo has been demonstrated on lung carcinoma ( rudd et al , 1994 ) , suggesting good specificity toward solid tumors . pharmacokinetic studies are very important for clinical trials and radioisotope - based drugs are very convenent for these approaches .
in brazil , crotalus durissus is widely distributed , except for the states of acre and espírito santo . in addition , there are isolated populations in open areas within savannas of the amazonian forest ( campbell & lamar 1989 ) . the diet of the species is assumed to be characterized by an extreme specialization in endothermic prey ; a feature that exists for only a few species of rattlesnake and which is thought to represent an ancestral trait ( clark 2002 ) . studies of food composition in populations from southeastern brazil indicated that rodents and small marsupials were the prey more widely eaten by rattlesnakes ( sant ' anna & abe 2007 ) ; however , birds ( vanzolini et al . 1980 ) and lizards ( santos & germano 1996 ) , can be considered as occasional food items in the c . durissus diet . in this work , we describe the feeding ecology of crotalus durissus in the central region of brazil and discus some strategies involved in the feeding of this rattlesnake .
marcovan porto , marco antonio de oliveira , lorenzo pissinatti , renata lopes rodrigues , julio alejandro rojas - moscoso , josé carlos cogo , konradin metze , edson antunes , césar nahoum , fabíola z . mónica , gilberto de nucci 2013 . the evolutionary implications of hemipenial morphology of rattlesnake crotalus durissus terrificus ( laurent , 1768 ) ( serpentes : viperidae : crotalinae ) . plos one 8 ( 6 ) : e66903 . doi : 10 . 1371 / journal . pone . 0066903 - get paper here
all food items were removed from the stomach and identified to the lowest possible taxonomic level . each of the contents was deposited in a glass container with the same identification number as the specimen ( voucher number ) . the intestinal content was determined while taking into account the type of food residue . in addition , available literature records of prey were included in this study , which analyzed the food composition for crotalus durissus from southeastern brazil ( santos & germano 1996 ; sant ' anna & abe 2007 ) .
overall , the diet composition of the south - american rattlesnake crotalus durissus , considering information of stomach contents identified from specimens in this study in combination with literature records ( santos & germano 1996 ; sant ' anna & abe 2007 ) , show a similar feeding patterns : rodents 66 . 05 % , marsupials 3 . 98 % , unidentified mammals 28 . 38 % and reptiles 1 . 59 % ; in reference to the reptiles , only six specimens - four of which identified in females had reptiles in their stomach .
as defined by crother et al . ( 2003 ) , following congruence of pook et al . ( 2000 ) , ashton and de queiroz ( 2001 ) , and douglas et al . ( 2002 ) , this species encompasses only the ranges of subspecies viridis and nuntius of traditionally defined c . viridis . in other words , the range extends from southern alberta and southern saskatchewan in canada , to the northern fringe of northern central mexico , west to idaho , wyoming , colorado , and extreme eastern arizona , east to the dakotas , western iowa , nebraska , central kansas , central oklahoma , and western and central texas in the united states ( stebbins 2003 , campbell and lamar 2004 ) . the ranges and relationships of crotalus oreganus and crotalus viridis in the four corners region and in northwestern colorado need further clarification ( hammerson 1999 ; brennan and holycross , 2004 ) . its elevational range extends from about 100 m asl near the rio grande ( campbell and lamar 2004 ) to at least 2 , 895 m asl ( 9 , 500 feet ) in colorado ( hammerson 1999 ) .
mammal specialization may be related to several life history strategies ( martins et al . 2002 ) . in some species of pitvipers , it could be associated with the increased venom toxicity in juveniles ; this may be a consequence of the need to immobilize larger prey such as a mammal ( andrade & abe 1999 ) . furthermore , the adoption of a juvenile diet based on mammals is more profitable energetically than an ecthothermic diet ( martins et al . 2002 ) . in crotalus durissus populations , the low frequency of ectothermic prey could explain such eventual facts .
the phospholipase a 2 activity of crotalus venom is well known and this activity is responsible for breakdown of phospholipid membranes leading to hemolysis ( zwaal et al , 1975 ) . to assess biological activity of cv , its hemolytic activity was measured . crude and labeled cv did not cause direct hemolysis ( not shown ) . an indirect hemolytic activity evaluation did not show any significant difference between unlabeled ( ic50 301 . 5 + 73 µg / ml ) and labeled cv ( ic50 247 . 7 + 49 µg / ml ) ( fig . 1 ) .
the acute exudative glomerular lesion of the rabbit ' s kidney caused by crotalus venom does not lead to a subacute or chronic glomerulonephritis . the hemorrhagic lesion of the glomerular tuft may show a process of repair characterized by the ingrowth , into the hemorrhagic masses , of endothelial cells from the uninjured part of the tuft . this process is , however , more analogous to the organization of a red thrombus than it is to any form of glomerular lesion known in man , and can hardly serve as an experimental demonstration of the mode of development of a subacute or chronic glomerular nephritis .
approximately 90 percent of rattlesnakes of the genus crotalus , exhibit ontogenetic shifts in food composition , changing from ectothermic to endothermic preys . these variations could be attributed to changes in morphological , behavioral and physiological characteristics during ontogeny ( mushinsky 1987 ) . alternatively a small percentage of rattlesnakes feed almost exclusively on endothermic preys , like c . durissus ( salomão et al . 1995 ; duarte 2003 ) , c . horridus and c . molossus ( clark 2002 ) . klauber ( 1956 ) gathered these three species and another , c . basiliscus , in the
durissus group
, to demonstrate this specialization .
the snakes examined represent a total of 452 individuals of crotalus durissus from the central region of brazil covering forest formations of the amazon and atlantic forests , caatinga and cerrado ; identified as 213 males , 167 females and 72 neonates and juveniles . we considered specimens to be neonates when their snout - vent length was smaller than 400mm ( hoyos , 2012 ) . the specimens are housed in the scientific collections of instituto butantan ( ibsp ) , museu de zoologia da universidade de são paulo ( mzusp ) , and universidade de brasília ( chunb ) . animals kept in captivity prior to being deposited in a scientific collection were excluded from this study .
the western rattlesnake ( crotalus viridis ) is a polytypic north american pit viper [ 16 , 23 – 24 ] , widely distributed across broad latitudinal and elevational gradients . it extends from the missouri river in the east , into saskatchewan , alberta , and british columbia to the north , along the west coast of the united states , and south into mexico ( fig 2 ; [ 23 ] ) . habitat includes deciduous and coniferous forests , scrub , prairie grasslands , shrub steppe , desert margins , and sand dunes as arrayed across a gradient from sea level to 4000m [ 24 ] . as a consequence , it displays considerable variation within and among populations , life stages , and subspecies .
crotalus venom ( cv ) produces neurotoxicity , coagulation disorders , systemic myotoxicity and acute renal failure , with possible additional heart and liver damage ( monteiro et al , 2001 and barraviera et al , 1995 ) . this venom contains enzymes , toxins ( crotoxin , crotamine , gyroxin , convulxin ) and several peptides ( barraviera et al , 1995 ) . pharmacokinetic and tissue distribution studies are very important for clinical use . although crotoxin has been labeled with 125 i for membrane interaction analysis ( krizaj et al , 1996 ) , radiolabeling of snake venom with 99m - technetium ( 99m tc ) has not been reported , neither has the utility of 99m tc based snake venom for in vivo studies been assessed .
we investigated food patterns in the diet composition of 452 specimens of crotalus durissus from central brazil . thirty - three items were recorded corresponding to four categories : rodents ( 75 . 76 % ) , marsupials ( 6 . 06 % ) , unidentified mammals ( 9 . 09 % ) and reptiles ( 9 . 09 % ) . adults of both sexes and some juveniles feed mostly on mammals , specifically rodents , it is the most active and abundant prey throughout the year mainly in areas from cerrado . in addition , we observed that in c . durissus there is a trend in the diet of females could be more diverse , maybe this can be associated to sexual differences involving different strategies of the feeding biology of this rattlesnake .
technetium - 99m ( 99m tc ) has been the radionuclide of choice for nuclear medicine procedures and experimental research . because of its optimal nuclear properties , 99m tc is suitable for high efficiency detection with the advantage of reduced radiological waste . crotalus venom ( cv ) has been shown to reduce tumors in clinical studies and tissue distribution studies are very important for clinical use . the goal of this work was to obtain cv labeled with 99m tc which preserves its biological activity . after labeling , biological activity was assessed by hemolytic activity evaluation . labeled and crude venom caused indirect hemolysis provided that the incubation medium contained an exogenous source of lecithin . high yield radiolabeled - cv was obtained and biological activity was preserved . the results suggest that 99m tc - cv can be a useful tool for biodistribution studies .
patrones de alimentación fueron investigados en la composición de la dieta de 452 ejemplares de crotalus durissus de brasil central . treinta y tres ítems fueron registrados , correspondientes a cuatro categorías : roedores ( 75 . 76 % ) , marsupiales ( 6 . 6 % ) , mamíferos no identificados ( 9 . 09 % ) y reptiles ( 9 . 09 % ) . los adultos de ambos sexos e individuos jóvenes se alimentaron básicamente de mamíferos , en específico de roedores , esta es la presa más activa y abundante durante todo el año , principalmente en las áreas de cerrado . además fue observado que en c . durissus existe una tendencia a que la dieta de las hembras sea más diversa , factor que podría estar relacionado a las diferencias sexuales que implican diferentes estrategias de alimentación en la biología de esta serpiente cascabel .
according to popular belief , one can tell the age of a rattlesnake by the number of rattles present at the end of its tail . a baby rattlesnake is born with the first segment of its rattle , called a
button
. as the snake grows ( and with each molting of its outer skin ) an additional segment is added to its rattle . younger snakes shed more often than older snakes , but on average , free - ranging snakes may molt three to six times a year . another clue to a snake ' s age is its color : timber rattlers darken as they age , and the darkest are old males . the scientific name , crotalus horridus , is formed from two latin words : crotalum , meaning
bell or rattle ,
and horridus , for
dreadful
—which makes reference to its venom .
a small species of the genus hepatozoon found in a specimen of crotalus durissus terrificus from the botucatu region , são paulo state , brazil is described . the morphologic alterations induced in the snake ' s erythrocytes by the presence of this parasite are described . morphology and morphometric analyses were performed using the qwin lite 2 . 5 computerized image analysis system ( leica ) . the hepatozoon possessed a small and short body ( 8 . 1 + / - 0 . 5 microm long and 3 . 8 + / - 0 . 4 microm wide ) , with round extremities . the cytoplasm varied from pale blue to basophilic and had no granulations . its nucleus was large , occupied a large area of the cytoplasm , and was irregular in shape and not condensed . despite its small size , this parasite induced important changes in the host cell . total parasitemia observed was 56 . 6 % .