Table Of Content330 NewAnapistulafromBrazil
projecting. Four eyes in two diads. Ratio of eyes Ms C. Ricardo Ott and Ms C. Renata Andrade for
2.0. Posterior lateral eyes separated by3 t imes their donating the specimens; Dr Eleonora Trajano for
diameter, lateral eyes of each side contiguous. Legs enabling the collection of material in São Domingos,
covered with setae and bristles, no spines. Leg formula Goiás; Dr Norman I. Platnick and Ricardo Ott for
1243.Legmeasurements:I:femur0.30/patella0.14/tibia helpful comments on the initial version of the manu-
0.22/metatarsus0.14/tarsus0.24/total1.04.II:0.28/0.12/ script. This studywas supported byCNPq and
0.20/0.12/0.22/0.94. III: 0.22/0.12/0.12/0.12/0.20/0.78. ‘‘Fundação de Amparo à Pesquisa do Estado de São
IV: 0.26/0.12/0.18/0.14/0.22/0.92. Palpal sperm duct Paulo’’ (FAPESP No. 00/00247-6; 99/05446-8). This
with anterior sinuosity, median tegular apophysis studyis part of BIOTA/FAPESP—The Biodiversity
inconspicuous (Fig. 22). Virtual Institute Program.
Female: Unknown.
Variation: Three males: total length 0.50–0.54; cara-
pace length 0.22–0.28; femur I length 0.26–0.32. References
Natural history: All specimens were collected in a
FORSTER,R.R.&PLATNICK,N.I.1977:Areviewofthespider
cave,approximately200 mfromtheentrance,inpilesof
familySymphytognathidae (Arachnida, Araneae). Am. Mus.
organic litter, using Winkler extractors. Novit.2619:1–29.
Distribution: Central-eastern Brazil, state of Goiás. GNASPINI,P.&TRAJANO,E.1994:Braziliancaveinvertebrates,
Other material examined: Onlythe types. withachecklistoftroglomorphictaxa.Revtabras.Ent.38(4):
549–584.
HÖFER, H. 1990: The spider community(Araneae) of a Central
Acknowledgements Amazonian blackwater inundation forest (igapó). Acta zool.
fenn.190:173–179.
We wish to thank Prof. Pedro Kiyohara and Miss HÖFER,H.&BRESCOVIT,A.D.2001:Speciesandguildstructure
Simone Perche de Toledo, of the ‘‘Laboratório de of a Neotropical spider assemblage (Araneae) (Reserva
Florestal Adolpho Ducke, Manaus, Amazonas, Brazil).
Microscopia Eletrônica do Departamento de Física
Andrias15:99–120.
Geral do Instituto de Física da Universidade de São
PLATNICK,N.I.2001:Theworldspidercatalog,version2.0.<http://
Paulo (USP)’’, for the scanning electron micrographs; research.amnh.org/entomology/spiders/catalog81-87>
Bull.Br.arachnol.Soc.(2003)12(7),330–332
Possible role of serotonin in the regulation of Introduction
feeding in the tarantula Aphonopelma hentzi
It is well known that alterations in neurotransmitter/
(Girard) (Orthognatha, Theraphosidae)
neuromodulator/neurohormone levels in mammals can
affect the regulation of feeding and the amount of food
Fred Punzo consumed(Fernstrom&Wurtman,1971).Inaddition,it
Box5F –DepartmentofBiology, hasbeenarguedthatanincreaseintheintakeofcertain
Universityof Tampa,
nutrients, such as carbohydrates, can result in an
Tampa,Florida33606,USA
increased rate of synthesis of 5-hydroxytryptamine
(5-HT, serotonin) in the blood and central nervous
Summary system(CNS)(Thibault&Booth,1999).Thisincreasein
serotonin synthesis can then alter feeding behaviour by
Exogenous administration of 5-hydroxytryptamine
decreasing the animal’s intake of carbohydrates.
(5-HT, serotonin) caused a significant decrease in body
Theassociationbetween5-HTandfoodconsumption
weight (12.9% weight loss) and in the number of prey
consumed over a 10-week feeding period, in adult females also occurs in insects. Cohen et al. (1988) demonstrated
of the tarantula Aphonopelma hentzi, as compared with thatthealterationof5-HTlevelshadasignificanteffect
non-treated controls (NTC) and spiders injected with on carbohydrate intake in noctuid caterpillars. As a
physiological saline (SAL). Injection of methyltryptophan
result of a reduction in 5-HT concentrations caused by
(MTP),a5-HTantagonist,causedanincreaseinnumberof
the administration of methyltryptophan, a serotonin
preyconsumed andbodyweight (25.7%)ascomparedwith
NTC and SAL animals. No significant differences were antagonist, caterpillars increased their overall feeding
found between NTC and SAL spiders with respect to rate as well as their rate of carbohydrate intake. Con-
changes in bodyweight or number of preyeaten. NTC versely,caterpillarsingestedlessfoodandcarbohydrates
spiders fed on crickets ad libitum exhibited an increase in
when 5-HT levels were artificiallyincreased. More
bodyweight of 7.8% after 10weeks. The possible role of
recently, Cohen (2001) showed that injections of 5-HT
5-HTintheregulationoffeedingbehaviourinarthropodsis
discussed. promoteddecreasesinoverallfeedingandcarbohydrate
F.Punzo 331
intake of 8.3% and 9.7%, respectively, in nymphs of the dose-response experiments (unpubl. data). Injections
cockroachRhyparobiamadera.Incontrast,injectionsof were made between the sternum and coxa of the second
methyltryptophan caused a 2.9% increase in overall leg.Spiderswereallowedtorecoverforaperiodof24h
feeding and a 7.1% increase in carbohydrate intake. and then deprived of food for two weeks before testing.
To myknowledge, there are no comparable data on Following this deprivation period, individually
the possible role of 5-HT in the regulation of feeding housed spiders from each group were weighed to the
behaviourinarachnids.Thepurposeofthisstudywas to nearest 0.1mg on a Sartorius electrical analytical bal-
determine if there is anyassociation between overall ance, and provided with crickets (Acheta domesticus) ad
food intake and 5-HT in the tarantula Aphonopelma lib, thus allowing them to feed to satiation. Ad lib
hentzi (Girard). feeding was continued for a period of 10weeks. The
number of crickets consumed byeach spider as well as
the spider weights were recorded after the 10week
Methods
feeding period. The crickets used were of similar sizes
Experiments were conducted on adult females of A. (0.4"0.02g) and theywere dusted with a multiple
hentzi originallycollected in Elgin, Texas in 1998 and vitamin, mineral and amino acid supplement powder
maintainedinthelaboratoryunder conditionsdescribed (Formula V/M/A, Bush Supply, Neodesha, Kansas).
previously(Punzo & H enderson, 1999). Females were Statisticalproceduresfollowedtheprotocolsdescribed
used because theyhave significantlylonger life spans byWoolf (1968).Bartlett’stestforhomogeneityof vari-
and feed throughout their adult lives (Baerg, 1958; ances showed equalityof variances for population
Punzo & Henderson, 1999). All spiders used in these samples. Data on the overall weight changes after the
experiments were of approximatelyequal size 10-weekfeedingperiodwereanalysedusingacompletely
(7.0"0.15g). randomised block-design (Model I, one-wayanalysis of
Sixtyfemale spiders were chosen randomlyand variance, ANOVA) with four treatments (groups 1–4)
divided into 4 groups, with each group containing 15 (n=15 spiders/ group). Data on the number of crickets
females: (a) Group 1–spiders injected with 5-HT; (b) consumed/week (10weeks) were analysed using a
Group 2–injected with methyltryptophan (antagonist); factorial design ANOVA (factor A, weeks of feeding;
(c) Group 3–injected with physiological saline; factor B, groups 1–4). Differences between individual
(d)Group4–non-treatedcontrols.Injectionprocedures means in both cases were tested for significance using a
followedthosepreviouslydescribed byPunzo(1988)for Student-Newman-Keuls(SNK)multiplerangetest.
Aphonopelma chalcodes. To summarise, spiders that
were to receive injections were first anaesthetised with
CO , and then injected with 12"l of either 2.7mg/kg Results
2
5-HT, 2.7mg/kg methyltryptophan (Sigma Chemical
The weights of the four groups of spiders (Groups
Co., St. Louis, Missouri), or 0.7% physiological saline,
1–4)attheendofthe10-weekfeedingperiodareshown
depending on their experimental group. These concen-
in Fig. 1. There was an overall significant effect of
trations were selected on the basis of previous pilot
treatments on weight change (F=13.98, df=3, 56,
p<0.01). No significant differences were found between
non-treated controls (NTC) and saline-injected (SAL)
Fig. 1: Bodyweight of adult females of Aphonopelma hentzi after a
10-week feeding period. Experimental groups (n=15/group) Fig. 2: Number of crickets eaten per week byadult females of
consistedofnon-treatedcontrols(NTC,Group2),andspiders Aphonopelma hentzi over a 10-week feeding period. Experi-
injectedwithserotonin(5-HT,Group1),physiologicalsaline mentalgroups(n=15/group)foreachweek,fromlefttoright,
(SAL, Group 3), and methyltryptophan (MTP, Group 4), a consisted of spiders injected with serotonin (black bars),
serotoninantagonist.Group0represents themeanweightfor non-treated controls (stippled bars), and those injected with
all spiders at the beginning of the experiments. Data are physiological saline (white bars) and methyltryptophan
expressedasmeans;verticallinesrepresent"SD.Seetextfor (hatched bars). Data are expressed as means; vertical bars
details. represent"SD.Seetextfordetails.
332 SerotoninandfeedinginAphonopelma
spiders (p>0.50). There were significant differences Acknowledgements
between NTC spiders and those injected with 5-HT
I wish to thank P. Merrett, J. Jackson, C. Bradford,
(p<0.05) and methyltryptophan (MTP) (p<0.05). There
and anonymous reviewers for comments on an earlier
wasalsoasignificantdifferencebetween5-HTandMTP
draft of the manuscript, B. Garman for consultation on
spiders (p<0.01).
statistical procedures, and T. Punzo and D. Sasko for
All adult females had an average weight of 7.05g
assistance in maintaining the spiders in captivity. I
("0.15 SD) at the beginning of the experiments, and
would also like to thank the Universityof Tampa for a
NTC spiders exhibited a mean weight of 7.6g ("0.18)
FacultyDevelopment GrantandaDeloResearchGrant
after 10weeks of feeding (a 7.8% weight increase). In
which made much of this work possible.
contrast, spiders injected with 5-HT showed a weight
loss of 12.9%, whereas those injected with MTP
exhibited a 25.7% weight gain.
References
There was an overall significant effect of treatments
on the number of crickets eaten per week (Fig. 2) ANDERSON, J. F. 1974: Responses to starvation in the spiders
(F=20.17, df=9, 56, p<0.01) over the 10-week period. LycosalentaHentzand Filistatahibernalis(Hentz).Ecology55:
No differences in food consumption were observed 576–583.
BAERG, W. J. 1958: The tarantula. Universityof Kansas Press,
between NTC and SAL animals (p>0.50). Spiders
Lawrence,Kansas.
injected with MTP ate significantlymore crickets than
COHEN, R. W. 2001: Diet balancing in the cockroach Rhyparobia
boththeNTCandSALgroups(p<0.01), whereasthose madera:doesserotoninregulatethisbehavior?J.InsectBehav.
injected with 5-HT ate significantlyfewer crickets 14:99–111.
(p<0.01). COHEN, R. W., FRIEDMAN, S. & WALDBAUER, G. P. 1988:
Physiologicalcontrolofnutrientself-selectioninHeliothiszea
larvae:theroleofserotonin.J.InsectPhysiol.34:935–940.
FERNSTROM, J. D. & WURTMAN, R. W. 1971: Brain serotonin
Discussion content: increase following ingestion of carbohydrate diet.
Science,N.Y.174:1023–1025.
Various physiological mechanisms that maybe
FOELIX, R. F. 1996: The biology of spiders (2nd ed.). Oxford
involved in the regulation of dietaryselection, diet UniversityPress, NewYork.
balancing, and responses to hunger in arthropods have FRIEDMAN, S., WALDBAUER, G. P., EERTMOED, J. E.,
been postulated, including haemolymph sugar levels NAEEM, M. & GHENT, A. W. 1991: Blood trehalose levels
havearoleinthecontrolofdietaryself-selection inHeliothis
(Scriber & Slansky, 1981; Nakamura, 1987; Friedman
zealarvae.J.InsectPhysiol.37:919–928.
et al., 1991), chemoreceptors (Kennedy, 1987; Simpson
KENNEDY,J.S.1987:Animalmotivation:thebeginningoftheend?
& Simpson, 1990), gut volume (Anderson, 1974; In R. F. Chapman, A. Bernays & J. G. Stoffaland (eds.),
Nakamura, 1987; Foelix, 1996; Punzo, 1989a, b, Perspectives in chemoreception and behavior: 17–31. Springer,
1995, 2000), and neurotransmitters/neuromodulators NewYork.
NAKAMURA,K.1987:Hungerandstarvation.InW.Nentwig(ed.),
(Fernstrom & Wurtman, 1971; Cohen et al., 1988). A
Ecophysiologyofspiders:287–295.Springer,Heidelberg.
recent studybyCohen (2001) showed that injection of
PUNZO, F. 1988: Learning and localization of brain function in
5-HT led to a decrease in overall feeding as well as an the tarantula spider, Aphonopelma chalcodes (Orthognatha,
increaseincarbohydrateintakeininsects.Theresultsof Theraphosidae).Comp.Biochem.Physiol.89A:465–470.
the current experiment suggest that this serotonin- PUNZO,F.1989a:Effectsofhungeronpreycapture andingestionin
Dugesiella echina Chamberlin (Orthognatha, Theraphosidae).
feeding relationship occurs in spiders as well. The
Bull.Br.arachnol.Soc.8:72–79.
manipulation of 5-HT levels caused adults of A. hentzi
PUNZO,F.1989b:Compositionofthehemolymphofmygalomorph
to alter their feeding behaviour. In addition, the admin- spiders.Comp.Biochem.Physiol.93A:757–760.
istration of MTP, a serotonin antagonist, caused an PUNZO, F. 1995: Feeding and preypreparation in the solifugid,
increase in the amount of preyconsumed and body Eremorhaxmagnus(Solifugae:Eremobatidae).Pan-Pacif.Ent.
mass. 71:13–17.
PUNZO,F.2000:Desertarthropods:lifehistoryvariations.Springer,
It remains to be determined what the proximate
Heidelberg.
mechanisms are bywhich 5-HT alters feeding rates in
PUNZO,F.&HENDERSON,L.1999:Aspectsofthenaturalhistory
arthropods and other animals. Do decreasing haemo- and behavioural ecologyof the tarantula spider Aphonopelma
lymph sugar levels associated with hunger cause con- hentzi (Girard, 1854) (Orthognatha, Theraphosidae). Bull. Br.
comitant changes in 5-HT concentrations in the brain arachnol.Soc.11:121–128.
SCRIBER,J.M.&SLANSKY,F.1981:Thenutritionalecologyof
andhaemolymph?Does5-HTactasaneurotransmitter
immatureinsects.A.Rev.Ent.26:183–211.
in neural pathways within the CNS or in peripheral
SIMPSON,S.J.&SIMPSON,C.L.1990:Mechanismsofnutritional
nerve fibres? Does it act as a neuromodulator or neuro- compensationbyphytophagous insects.InE.A.Bernays(ed.),
hormone affecting electrogenic events in specific brain Plant insect interactions 2: 111–160. CRC Press, Boca Raton,
regions associated with feeding and the perception of Florida.
satiation? Future studies should address these questions THIBAULT, L. & BOOTH, D. A. 1999: Macronutrient-specific
dietaryselection in rodents and its neural basis. Neurosci.
in an attempt to understand more fullythe proxi-
Biobehav.Rev.23:457–528.
mate factors associated with the regulation of feeding
WOOLF, C. M. 1968: Principles of biometry. Van Nostrand,
behaviour and/or diet selection in arthropods. Princeton,NewJersey.
