1
Changes in mo phology o e ime due o dena u ing agen s in an
e hanol and campho solu ion
Hanne Jacobs1, Ga in Cael2, S e anie Bau ois1
1 Uni e si y o An we p, Blindes aa 9, An we p, Belgium
2 Royal Museum o Cen al A ica, Leu enses eenweg 13, Te u en, Belgium
Co esponding au ho : Hanne Jacobs ([email p o ec ed])
Copy igh : © Hanne Jacobs e al.
This is an open access a icle dis ibu ed unde
e ms o he C ea i e Commons A ibu ion
License (A ibu ion 4.0 In e na ional – CC BY 4.0).
Resea ch A icle
Abs ac
The e hanol collec ions o he A icamuseum equi e an app o ed dena u ing agen , ha
can be used o op-up con aine s in which, his o ically, campho -dena u ed e hanol has
been used. Dena onium benzoa e, die hyl e he and isop opyl alcohol we e e alua ed
on hei abili y o p ese e Li hoba es ca esbeianus (Shaw 1802) in he long e m. The e
was no isual di e ence be ween he colo s o he p ese a ion liquids o e ime, bu
p ecipi a es we e o med in almos all o he es con aine s. The snou -u os yle leng h
and he leng h o he high o he es specimens we e assessed o e ime. A e a i icial
aging, specimens in a mix u e o e hanol dena u ed wi h isop opylalcohol sh unk less
han hose in o he mix u es, e en he con ol g oup, albei by only a small ac ion.
Key wo ds: Amphibian collec ions, Conse a ion s udies, Dena u ing e hanol, Fluid p es-
e a ion, Mo phology
In oduc ion
The A icamuseum in Te u en, Belgium (RMCA) possesses a la ge collec ion
o p ese ed animals (A icamuseum 2025). A subs an ial pa o he e e-
b a e collec ions has been s o ed in con aine s con aining 70% dilu ed e hanol,
dena u ed wi h 0.35 g campho pe li e o he alcohol and wa e mix u e, o de-
cades. Howe e , he Eu opean Union doesn’ lis he use o campho as a dena-
u ing agen o e hanol (EUR-Lex 2018). O e ime, he p ese a i e luid in he
con aine will e apo a e and need opping up, o he wise he specimens will d y
ou and de e io a e (Simmons 2014). Re illing he con aine s o exis ing speci-
mens wi h e hanol ha is dena u ed wi h campho is no longe allowed. Ideally,
he A icamuseum would use non-dena u ed e hanol, as his is ecommended
o collec ions, hence he sea ch o ano he dena u ing agen , ha can be add-
ed o an e hanol and demine alized wa e mix u e, o op up he con aine s wi h-
ou p o oking a ha m ul chemical eac ion wi h he exis ing p ese a ion luid.
In his pape , al e na i e dena u ing agen s we e e alua ed ha could be
added o he specimens p ese ed in e hanol wi h campho . Th ee dena u ing
agen s we e es ed: dena onium benzoa e, die hyl e he and isop opyl alco-
hol. The sa e y and heal h o he museum s a was aken in o accoun . Each
o hese compounds a e pe mi ed as dena u ing agen s o e hanol by he
Academic edi o : Luis Ce íaco
Recei ed:
11 June 2025
Accep ed:
29 Sep embe 2025
Published:
10 Oc obe 2025
Ci a ion: Jacobs H, Cael G, Bau ois S
(2025) Changes in mo phology o e
ime due o dena u ing agen s in an
e hanol and campho solu ion. Na u al
His o y Collec ions and Museomics
2: 1–12. h ps://doi.o g/10.3897/
nhcm.2.161606
Na u al His o y Collec ions and Museomics 2: 1–12 (2025)
DOI: 10.3897/nhcm.2.161606
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NHCM 2: 1–12 (2025), DOI: 10.3897/nhcm.2.161606
Hanne Jacobs e al.: Changes in mo phology due o dena u ing agen s
Eu opean Union (EUR-Lex 2018). Die hyl e he and isop opyl alcohol a e o en
used on hei own as p ese a ion liquids, making hem a sui able al e na i e
(Simmons 2014). Dena onium benzoa e has no his o y as a p ese a ion liquid
bu is o in e es . I is a bi e ing agen used in a wide a ie y o household p od-
uc s o p e en diges ion o as a dena u an o alcohol wi hou changing he
con en s (Be ning e al. 1982).
Twen y esh specimens o Li hoba es ca esbeianus we e p ese ed wi h
70% e hanol, campho and one o he h ee dena u ing agen s men ioned
abo e, o e alua e he p ese a ion p ope ies. The samples we e assessed
bimon hly o quan i y he impac o he dena u ing agen on he specimen. The
snou -u os yle leng h (SUL) and he leng h o he high (THL) we e measu ed
(Fig. 1), as he mix u e can sh ink he specimen up o six pe cen (Deichmann e
al. 2009). This ai is undesi able in a scien i ic collec ion ha is egula ly used
o axonomic esea ch. The sh inkage is caused by dehyd a ion because alco-
hol eplaces wa e in he issue o specimens. All alcohols will cause sh inkage
bu he amoun o sh inkage can a y be ween ypes o alcohol (Ci e i 1971).
Addi ionally, he colo and anspa ency o he p ese a ion liquid was isually
moni o ed o ensu e ha he p ese a ion mix u e would no become opaque.
Me hods
Theo e ical compa ibili y and sa e y
I was impo an o check he long- e m compa ibili y o each componen be-
o e making he mix u es. Campho is soluble in e hanol (Na ional Cen e o
Bio echnology In o ma ion 2024) and will he e o e also be dissol ed by o he
alcohols like isop opanol. Howe e , he unc ional ca bonyl g oup o campho
will eac wi h se e al aldehydes, ke ones and s ongly educing o s ongly ox-
idizing compounds (Mahdy e al. 2022). Dena onium benzoa e is chemically
ine (Be ning e al. 1982) and should be s able in he p esence o ai o ligh
(The moFishe Scien i ic 2024). Bo h isop opylalcohol and e hanol ha e low e-
ac i i y. E he is a base and can eac wi h se e al acids and can pho o-oxidize
o an explosi e compound, die hyl e he pe oxide (A o a and Gau am 2025).
Wo king wi h luid collec ions aises conce ns on he heal h and sa e y o he
s a dealing wi h hese collec ions (Van Dam 2003; Clo h Wo ke s Founda ion
2012; Neumann e al. 2022). In his pape we ha e used he c i e ia de ined
by Van Dam o assess he lammabili y and oxici y o he mix u e. Howe -
e , he e we e almos no di e ences be ween he mix u es when i e alua ed
hese pa ame e s because o how simila he composi ion o he mix u es was.
The base o each mix u e consis ed o 70% e hanol and 0.35 g campho pe
Figu e 1. Mo phological measu emen s: he snou -u os yle leng h (SUL) and he high
leng h (THL). The measu emen o he high was aken by measu ing he leng h be-
ween he cloacal gap and he ex e nal high join .
3
NHCM 2: 1–12 (2025), DOI: 10.3897/nhcm.2.161606
Hanne Jacobs e al.: Changes in mo phology due o dena u ing agen s
li e wa e and e hanol; each mix u e had a 1% di e ence in composi ion. The
dena u ing agen s would mos likely only ei he slow down o speed up any
eac ions caused by e hanol, campho o he specimen. The e o e, we would
heo e ically expec all esul s o be simila .
None o he es ed mix u es we e sa e enough acco ding o he ca ego ies in
an Dam (2003). The la ge amoun o e hanol in each mix u e immedia ely ails
each mix u e o ca ego ies “Toxici y” and “Flammabili y”. In o de o succeed in
he ca ego y he compound had o ha e a sco e equal o 1 o lowe on he Haza d
Ra ing F (Flammabili y), as de ined by he Na ional Fi e P o ec ion Agency (NFPA).
As he aim o his esea ch was o e alua e which dena u an s could be mixed
wi h e hanol and/o each o he , he p esence o e hanol was indispensable, which
means he mix u e immedia ely ails he ca ego ies “Toxici y” and “Flammabili y”.
The mix u es will be e e ed o as he ollowing om his poin on in he
pape :
Expe imen al se up and s a is ical me hodology
Fo his expe imen he species Li hoba es ca esbeianus was selec ed as a sui -
able es subjec . This og species is in asi e in Belgium and specimens a e
egula ly eu hanized. The ogs used in his s udy we e pa o he LIFE-3n Bull-
og p ojec .1 Fu he mo e, we assumed ha because ogs ha e a semi-pe -
meable skin, hey would abso b he p ese a ion luid easily and migh be mo e
p one o sh inkage.
Twen y esh specimens o Li hoba es ca esbeianus we e ixed by injec ion
o 4% o maldehyde bu e ed wi h 0.5–1.5% me hanol and we e w apped in a
cheeseclo h pe mea ed wi h a 4% o maldehyde solu ion o 24 hou s. In o de
o simula e he cu en si ua ion in he A ica museum wen y glass con aine s,
each con aining one specimen, we e illed hal way wi h e hanol dena u ed wi h
campho o e lec samples in he cu en si ua ion. They we e di ided in o ou
se s o i e specimens. Each se was opped up using e hanol dena u ed wi h
one o h ee dena u ing agen s (isop opyl alcohol, dena onium benzoa e, o di-
e hyl e he ). A ou h es se was opped up wi h he base solu ion o e hanol
and campho , and was used as a con ol g oup. Un o una ely, no pu e e ha-
nol was a ailable o his expe imen . The e hanol used was al eady dena u ed
wi h me hyl e hyl ke one and dena onium benzoa e. The consequences o he
use o his speci ic p oduc we e elabo a ed upon in chap e “Discussion”.
1 The p ojec aims o sus ainably educe popula ions by eleasing s e ilized males.
These ogs we e e ile and no longe o use in he s udy. They we e dona ed by P o .
D . Descamps (Uni e si y o Hassel ) o his speci ic p ojec .
Table 1. Composi ion o each mix u e.
Name Componen s
ECI E hanol, campho , isop opyl alcohol
ECD E hanol, campho , dena onium benzoa e
ECE E hanol, campho , die hyl e he
EC (Re e ence mix u e) E hanol, campho
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NHCM 2: 1–12 (2025), DOI: 10.3897/nhcm.2.161606
Hanne Jacobs e al.: Changes in mo phology due o dena u ing agen s
E e y wo weeks he snou -u os yle leng h (SUL) and he leng h o he high was
measu ed, based on Wa e s e al. (2016), using a Mi u oyo analog calipe , wi h a
p ecision o 0.02 mm, o quan i y he sh inking o he specimen. These measu e-
men s we e chosen because bo h he body and he high a e gene ally measu ed
in axonomical esea ch. A o al o se en measu emen s we e made o e a pe iod
o h ee mon hs, including a p e-p ese a ion measu emen as baseline. Addi ion-
ally, pic u es we e aken bimon hly o isually check di e ences in colo and opac-
i y o he liquid h oughou ime. All pic u es we e aken unde he same (a i icial)
ligh sou ce using he same whi e backg ound. A Calib i e Colo Checke Passpo
Pho o was used o ensu e ha any u he changes in ligh ing could be ixed a e -
wa ds (Fig. 2). All measu emen s we e aken by he i s au ho , o ensu e consis-
ency, and o allow he measu emen s o be compa ed o each o he .
A nonlinea mixed e ec s model was p oposed o quan i y he change in
bo h leng hs h oughou ime:
Leng h = Elow * (1 + Ehigh * exp(- * log(2)/Thal ))
In his model Ehigh ep esen s he maximum amoun o loss o leng h as a
pe cen age. Elow ep esen s he size o a og a e i would ha e heo e ically
expe ienced his maximum amoun o loss o leng h, is ime in days since he
s a o he expe imen , and Thal quan i ies he ime equi ed o achie e hal o
he maximal sh inkage and can he e o e be associa ed wi h he a e o achie e
he maximal sh inkage. The model i sel is a modi ied e sion o an exponen ial
decay model as used in nuclea physics (Pommé e al. 2024) o pha maco-
kine ic modeling (Gab ielsson 2001). The modi ica ion he e is ha he e’s an
exponen ial decay om he ini ial le el o he new, s able le el.
The model desc ibed he a e age sh inking e ec o e ime bu i also ac-
coun ed o he indi idual de ia ion o each og. No e ha in ypical s a is ical
analyses and modeling, one assumes independence o he obse a ions. In his
se ing, da a o he same se o ogs was assessed mul iple imes o e ime,
hence, no independen samples. The e o e, a mixed e ec s model (Pinhei o e
al. 1995; Ve beke and Molenbe ghs 1997) was u ilized. This accoun s o he
Figu e 2. An example o a pic u e aken o ECD2. Please no e he sligh ly yellowed hue
in he liquid.
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NHCM 2: 1–12 (2025), DOI: 10.3897/nhcm.2.161606
Hanne Jacobs e al.: Changes in mo phology due o dena u ing agen s
he e ogenei y be ween he di e en longi udinal p o iles by inco po a ion o an
independen andom e ec a Elow and Ehigh ( high measu emen ), and co ela -
ed andom e ec s a Elow and Ehigh as well as an independen andom e ec a
Thal (SUL measu emen ) (Da idian and Gil inan 2000), i.e., quan i ying he size
o he ogs a popula ion le el, while accoun ing o animal speci ic de ia ions.
A i icial aging
A he end o he h ee-mon h ollow-up, all wen y specimens we e aged in
hei con aine based on he me hod desc ibed by Von End e al. (2000). In his
pape , he long e m s abili y o ea he s and hai in 70% e hanol was in es i-
ga ed by hea ing o 180 °C o 1 and 2 days. This me hod was adap ed o his
esea ch: he specimens in hei espec i e con aine s we e hea ed in a ho wa-
e ba h o 40 °C o se en hou s. The inc eased empe a u e will accele a e any
chemical o biophysical eac ions ha no mally would ake place o e a longe
pe iod o ime. The main eason o lowe ing he empe a u e was he p esence
o die hyl e he which could o m dange ous die hyl e he pe oxide compounds
when hea ed. Each specimen was measu ed igh be o e and igh a e he
aging p ocess in o de o assess he long- e m e ec o he dena u an s.
The pu pose o he a i icial aging was o demons a e an absence o u he
de e io a ion o he samples. The di e ence be ween be o e (day 118) and a e
(day 126) a i icial aging was analyzed using equi alence es ing (Chow and
Liu1999; Pa e son and Jones 2017). The da a was pai wise iden i ied and loga-
i hmically ans o med wi h a linea mixed e ec model whe e each og se ed
as i s own e e ence and es obse a ion. The model included an indica o o
p e-, e sus pos -aging. The e ec o aging was assessed by quan i ying he
di e ence be o e and a e he a i icial aging p ocess on a loga i hmic scale.
Resul s
Analysis o he da a
The size o SUL and high was measu ed bimon hly o e a pe iod o 3 mon hs.
Each specimen ini ially expe ienced a apid exponen ial loss o leng h in he i s
ew weeks, which slowed o e ime. Measu emen s we e depic ed in Figs 3, 4.
The da a was modeled while he di e ence be ween he di e en es com-
pounds was assessed bo h a he pa ame e s Ehigh and Thal . Inco po a ion o
he es compounds a he le el o Thal i he da a bes . The model i he aw
da a o he SUL and he size o he high o each specimen adequa ely. The SUL
in he EC- e e ence g oup dec eased 4.69% wi h a Thal o 14 days. The leng h
o he high in he EC- e e ence g oup dec eased 4.46% wi h a Thal o 20 days.
The change in Thal o he o he compounds ela i e o he e e ence is depic ed
in Table 2. No e he independence o he maximal amoun o sh inkage o he
di e en compounds used. The maximum loss o leng h o he high consis ed
o 4.46 ± 1.26%. The loss o SUL a e p ese a ion in EC is 4.93 ± 1.26%. In his
se ing he educ ion was 11.4, -14.0 and -6.66 o ECD, ECE and ECI, espec-
i ely ela i e o EC.
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NHCM 2: 1–12 (2025), DOI: 10.3897/nhcm.2.161606
Hanne Jacobs e al.: Changes in mo phology due o dena u ing agen s
Figu e 3. The SUL o each se was depic ed a popula ion le el in a p edic able dis ibu-
ion g aph. Each poin is an indi idual measu emen o a og a one speci ic momen .
The popula ion a e age is depic ed by he black line. Colo ed in e als we e used o
display he p edic ion in e als. F om he ou e colo o he inne colo , each colo ep e-
sen ed 90%, 80%, 70%, 60% and 50%.
Figu e 4. The leng h o he high was ep esen ed in he same way as he SUL. Fo expla-
na ion o he g aph, see Fig. 1.
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NHCM 2: 1–12 (2025), DOI: 10.3897/nhcm.2.161606
Hanne Jacobs e al.: Changes in mo phology due o dena u ing agen s
No e ha he es ima ed di e ences we e no s a is ically signi ican , which
was likely due o he small sample size o each o he compound g oups. In e -
p e a ion o hese esul s can be ound in he chap e “Discussion”.
A i icial aging
The e ec o aging on each se was es ima ed by quan i ying he di e ence
be o e and a e he a i icial aging p ocess on a loga i hmic scale. The expo-
nen s o his di e ence esul ed in he a e age sh inkage in pe cen age ha
ook place du ing he a i icial aging p ocess (Table 3).
Visual di e ences
Du ing he i s mon h a p ecipi a ion eac ion was no iced in almos all he glass
con aine s. The p ecipi a e was no analyzed. Because o he unknown na u e
and unknown consequences o he p ecipi a e, his eac ion was undesi able.
The e o e each es ed se was judged on how much p ecipi a ion was o med
du ing he en i e expe imen . Each es specimen was di ided in o ou ca ego-
ies based on he amoun o p ecipi a ion a he bo om o he con aine (Table 4).
Discussion
Two impo an sideno es need o be made abou he execu ion o he expe -
imen . Fi s , no pu e e hanol was ob ained p io o he esea ch. Only e hanol
ha was al eady dena u ed wi h me hyl e hyl ke one and dena onium benzoa e
was a ailable o use. As he base mix u e was he same o each ca ego y,
we assumed ha he di e ences be ween he g oups would p ima ily be in lu-
enced by he di e ence in dena u an s, and he e o e he esul s would s ill e-
lec he sui abili y o each dena u an . Howe e , any obse ed eac ions migh
ha e also ha e been in luenced by any eac ion be ween he ke one and o he
Table 2. The ela i e change in Thal compa ed o he e e ence compound o he SUL
and high.
SUL Thigh
ECD 64% as e 340% slowe
ECI 67% as e 70% as e
ECE 86% as e 30% as e
Table 3. The a e age sh inkage o he snou -u os yle leng h and he size o he high o
each mix u e. No e ha he 90% con idence in e als we e omi ed o eadabili y easons.
SUL Size o he high
EC 1.98% smalle 0.0302% smalle
ECD 3.15% smalle 0.0366% smalle
ECI 0.797% smalle 0.0464% smalle
ECE 1.98% smalle 0.0221% smalle
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Hanne Jacobs e al.: Changes in mo phology due o dena u ing agen s
componen s. Campho has he endency o eac wi h di e en ke ones, bu no
eac ion be ween, speci ically, me hyl e hyl ke one and campho has ye been
no ed in esea ch (Mahdy e al. 2022).
Secondly, i is also impo an o emembe he small sample size used in
his expe imen (due o ime cons ain s and limi ed lab space). The limi ed
numbe o specimens used mean ha he conclusions we e s a is ically un-
de powe ed in con as o s udies wi h a la ge sample size (Hayek and Heye
2004). Conc e ely, an inc eased numbe o specimens would dec ease he un-
ce ain y su ounding esul s ound in his esea ch because any de ian da a
would become less signi ican . Ne e heless, he ollowing conclusions could
be made om he da a.
All specimens sh unk du ing he expe imen , excep one sample ea ed
wi h ECI, whose high inc eased by 1.30 mm in he i s wo weeks o he
expe imen . The e a e se e al possible explana ions o his. Al hough his
could be due o a measu ing e o du ing he expe imen , his phenomenon
has been obse ed be o e in a s udy by Lee (1982).The SUL o six Rhinella
ma ina (Linnaeus 1758) expanded by an a e age o +1.9% o male speci-
mens and +1.2% o emale specimens, while eigh specimens sh unk. An
inc eased sample size o a epea o he expe imen could ei he con i m o
nega e his phenomenon.
Du ing he expe imen each specimen sh unk du ing he i s ew weeks.
The sh inking caused by he e hanol, campho and dena u ing agen s abilized
h oughou ime. Al hough he ime o each his maximal change di e ed be-
ween he compounds, i was conside ed o ha e limi ed p ac ical impac : The
p ese a ion o he samples is in ended o mul iple decades, whe eas he es-
ima ed hal -li es we e in he magni ude o one mon h, as seen in Figs 1, 2.
A aining he maximal sh inkage a e 5 hal -li es would he e o e con i m he
es ic ed ele ance o he es ima ed di e ences and sugges ed only ini ial im-
pac in he ansi ion p ocess om dena u an s wi h campho . No e ha no
s a is ically signi ican di e ences we e ound (based on likelihood a io es :
Table 4. The di e en ca ego ies o he amoun o p ecipi a ion and which specimen belonged o which ca ego y.
Sco e 0 1 2 3
Desc ip ion The e is no isible
p ecipi a e.
The e is li le isible
p ecipi a e.
The e is enough p ecipi a e
o ill he en i e lowe ing in
he con aine
A la ge amoun o
p ecipi a e obs uc s he
iew o he bo om o he
con aine .
Example
EC 3 ECE 1 ECE 5 ECD 2
Specimen
belonging o he
ca ego y
ECI 4 ECI 2 ECI 5 ECI1
EC2 ECI 3 ECE 2 ECD 2
EC3 ECE 1 ECE 4 ECD 4
EC4 ECE 3 ECE 5
ECD 3 EC 1
ECD 5 EC 5
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NHCM 2: 1–12 (2025), DOI: 10.3897/nhcm.2.161606
Hanne Jacobs e al.: Changes in mo phology due o dena u ing agen s
p = 0.06064359 and p = 2.501712e-07 o SUL and high, espec i ely) in he
sh inkage be ween he se s be o e he a i icial aging p ocess, howe e , his
migh be ela ed o he limi ed sample size in he expe imen . No e ha his
s udy was no a p io i powe ed o de ec a p especi ied biologically ele an
e ec , hence all p- alues should he e o e be conside ed as hypo hesis gene -
a ing a he han hypo hesis con i ming.
When conside ing he long- e m changes, a mino di e ence in a e age
sh inkage was no ed a e he a i icial aging p ocess. The SUL o se ECI
sh unk he leas o all se s (including con ol se EC) wi h a sh inkage o
only 0.797%. Specimens o se EC sh unk by 1.98%.Se ECE pe o med sim-
ila o se EC in his ca ego y. Se ECD pe o med he wo s wi h a sh inkage
o 3.15%.The leng h o he highs o se ECI sh unk on a e age by 0.0464%.
Despi e i being he la ges sh inkage o he leng h o he highs, his sh ink-
age was small enough o be conside ed o limi ed biological ele ance. The
highs o he specimens mos likely sh unk less han he SUL because i con-
ains less so issue.
No di e ence be ween colo o he se was ound. The liquid in each con ain-
e u ned o a sligh yellowish hue, bu each specimen was s ill clea ly isible.
Any a ia ion in colo could ha e been caused by a di e ence in a and blood
p esen in each specimen, which could ha e been ansmi ed o he liquid.
Ano he issue in he con aine s was he o ma ion o p ecipi a es because o
i s unknown composi ion and abili y o cloud he specimen. This in luenced he
opaci y o he liquid. A e isual inspec ion, es se EC appea ed o ha e he
leas amoun o p ecipi a ion (Table 3), espec i ely ollowed by es se ECI,
es se ECE and, inally, es se ECD. The exac composi ion o he p ecipi a-
ion was unknown, bu possibly caused by he p e iously men ioned addi ion
o me hyl e hyl ke one and dena onium benzoa e. Conside ing ha se ECD had
he mos p ecipi a ion and ha dena onium benzoa e was p esen in all se s
due o he impu i y o he e hanol, he p ecipi a ion was mos likely o blame
on in e ac ions be ween campho and dena onium benzoa e despi e he la e
being conside ed chemically ine .
Conclusions
I should be ei e a ed ha he expe imen al se -up was es ic ed o a single
species, Li hoba es ca esbeianus. Di e en species migh eac di e en ly o
he same expe imen . Rega dless, epe i ion and/o ampli ica ion o he expe -
imen is equi ed o lessen s a is ical e o . Pu e e hanol would be needed as a
base o he solu ions. Fu he mo e, i migh ha e been in e es ing o omi some
specimens om he apid aging p ocedu e, o check how ele an he apid
aging was in he o e all pic u e.
The e we e minimal di e ences in sh inkage and colo change be ween
he es ed se s. Each specimen sh unk wi hin he i s ew weeks o es ing,
excep o he high o ECI1. This sh inkage s abilized h oughou ime. The
h ee es ed dena u ing agen s―dena onium benzoa e, isop opyl alcohol and
die hyl e he ―did no cause a signi ican di e ence in sh inkage du ing he i s
ew mon hs o es ing. Howe e , a e a i icial aging, specimens in a mix u e
wi h isop opyl alcohol sh unk he leas on a e age e en while excluding he
