Table Of Content2006. The Journal of Arachnology 34:214-220
ECOLOGY OF THESTYLUS AURANTIURUS OF THE PARQUE
ESTADUAL DA SERRA DA CANTAREIRA, SAO PAULO,
BRAZIL (SCORPIONES, BOTHRIURIDAE)
Humberto Y. Yamaguti and Ricardo Pinto-da-Rocha: Departamento de Zoologia,
Institute de Biociencias, Universidade de Sao Paulo, Caixa Postal 11461, CEP
05422-970, Sao Paulo, SP, Brazil. E-mail: [email protected]
ABSTRACT. Individuals of a Thestylus aurantiurus Yamaguti & Pinto-da-Rocha 2003 population in
the Parque Estadual da Serra da Cantareira (Sao Paulo, SP, Brazil) show an increase ofactivity throughout
the year. This increase is related to the reproductive season of these scorpions, from September to No-
vember. The abundance of scorpions was related to environmental factors in four different areas of the
park. More scorpions were collected in the higher areas, far away from water sources ofthe park and not
exposed to flooding. A short description of the Thestylus aurantiurus burrows is also presented.
Keywords: Scorpiones, Thestylus aurantiurus, Atlantic Rainforest, seasonality, relative abundance
Scorpions are extremely sedentary animals. tain Brazilian scorpions during courtship, e.g.,
According to Polis (1990a), they share the re- Bothriurus araguayae Vellard 1934.
cord with many spiders for the lowest arthro- The genus Thestylus Simon 1880 has been
pod metabolic rates ever recorded. Some spe- little studied due to its restricted geographical
cies spend 97% of their lives inside their distribution and low abundance. The only
burrows, and they can exist one year without study on the reproduction of Thestylus was
feeding (Polis 1990a). This is largely due to Machado & Vasconcellos-Neto (2000). They
the “sit-and-wait” type of foraging activity described the courtship behavior of T. auran-
adopted by most scorpions, which consists of tiurus Yamaguti & Pinto-da-Rocha 2003
being immobile and awaiting any prey that (mentioned as T. glasioui (Bertkau 1880)).
passes within reach. However, during the re- According to the authors, the reproductive pe-
productive period, scoipions present certain riod is very seasonal, occurring during the hot
and wet season (beginning in October), in Ser-
behavioral changes. These changes occur
ra do Japi (23°17'S; 47°00'W), Jundiai, SP,
mainly in surface activity, such as a reduction
Brazil.
in female foraging activity and an increase in
Abundance and its relationship to environ-
male surface activity in search of females
mental factors is another well studied aspect
(Benton 2001).
of scorpion ecology. Evidence suggests that
Courtship behavior is well-studied in scor- scorpions are selective when choosing a place
pions. The behavior of 35 species of six fam- to build their burrows. Polis & McCormick
ilies was described, from the about 1500 spe- (1986) studied desert scorpions and noticed
cies and 16 families listed in Fet et al. (2000). differences of abundance among the species
The courtship behavior of many bothriurid related to the environment. Hofer et al. (1996)
species was studied, mainly by Peretti (1995, presented a study relating environmental as-
1997). However, there are few works on the pects of different habitats of a Central Ama-
reproductive activity of scorpions. Peretti zon Rainforest with the relative abundance of
(1997) studied the reproductive characteristics a certain scorpion species. Koch (1977, 1978)
of Argentinean scorpions, describing the re- studied burrows in the genus Urodacus Peters
productive period, interval between mating 1861 (Urodacidae), observing a different kind
and litter birth behavior, and period of litter of burrow for each Urodacus species and ver-
birth ofsome bothriurid scorpions. Matthiesen ifying that environmental aspects influence
(1968) studied the courtship behavior of cer- burrow site location.
214
YAMAGUTI & PINTO DA-ROCHA—ECOLOGY OF THESTYLUSAURANTIURUS 215
The study presented here was conducted to tral point. Strips of canvas of 5.0 X 0.5 m,
assess the activity ofa population ofThestylus fixed with wooden stakes, connected each out-
&
aurantiurus (Figs. 1 2) throughout the lying bucket to the central one in orderto steer
course of one year (February 2000-January the animals into the buckets. Ten traps were
2001), and the relationship between relative placed in each area, comprising a total of 40
abundance and environmental aspects in buckets per area. The central point of each
m
Parque Estadual da Serra da Cantareira, Sao trap was 20 from the next in a straight line.
Paulo, SP, Brazil. The bottom of each bucket was perforated to
prevent the accumulation of rain water. The
METHODS
— size of the holes prevented the animals from
Studied area* Collections were made escaping.
throughout one year in four areas of the At™ Traps were checked every morning and
lantic Rainforest. These areas are located in covered on the last day to avoid captures out-
the Nucleo Pedra Grande ofthe Parque Estad- side the sampling period. Each trap was num-
ual da Serra da Cantareira (23°22'S; bered individually, enabling the identification
46°36'W), Sao Paulo, SP, Brazil, in a project of scorpions according to trap, date and col-
conducted together with Universidade Ban- lection area. Since the traps were originally
deirante de Sao Paulo (UNIBAN). erected to capture small mammals alive, apre-
Area 1 named Pedra Grande (23°26'30"S; serving liquid was not used, hence animals re-
46°38'20"W at an elevation of 1050 m), pos- mained alive until the moment of capture.
sesses dense vegetation, and well-developed Thus, there was a possibility of the scorpions
small and medium-sized understory strata, having been devoured by toads, lizards or ro-
with lianas and bamboo groves. In area 2, dents inside the buckets. So, the number of
named Lago das Carpas (23°25'40"S; collected scorpions may be higherthan theob-
46°36'06"W, 700 m) possesses dense under- served. However, the results probably would
story, with flooded areas and bamboo groves. not change, because the patterns ofseasonality
Area 3 named Divisa (23°25'48"S; are clearcut in this work.
46°38'00"W, 1050 m), is located on the This kind of sampling probably produced a
boundary between the municipal districts of different result from active collection (e.g.
Sao Paulo and Mairipora. It possesses dense with ultraviolet light), but with pitfall traps,
vegetation, with numerous lianas and some the seasonality would be more evident. Preg-
exotic species, such as Pinus sp. Area 4, nant females were identified according to Far-
named Sede (23°27^03"S; 46°38'06"W, 650 ley (2001), with dissections and observation
m), is characterized by lush vegetation, with of the ovariuterus, and comparison with Far-
steep slopes, many lianas, a large amount of ley’s photos. Voucher specimens were depos-
low vegetation and flooded areas. ited in Museu de Zoologia da Universidade de
The values ofmonthly median temperatures Sao Paulo (MZSP), Sao—Paulo, SP, Brazil.
and monthly total rainfall presented in this Environmental data. The following en-
work were supplied by the Companhia de Sa- vironmental data were gathered: amountoflit-
neamento Basico do Estado de Sao Paulo ter, density ofthe canopy, perimeter ofclosest
(SABESP). These data were recorded at Paiva 10 trees measured at the breast height (PBH),
Castro^s dam (23°22'11"S; 46°40'07"W), in soil composition and elevation. All these data
the municipal district ofMairipora, nearto the were recorded on the same day, in May 2002
Parque Estadual da Serra d—a Cantareira. (subsequent to the period of collection), close
Ecological samplings. Twelve monthly to the places where traps were located. The
collections, ofnine days each, were undertak- amount of litter of an area of 0.25 m^ was
en between February 2000 and January 2001. measured. Ten samples were collected ran-
Scorpions were collected in drift fence pitfall domly in each area totaling 40 samples. Each
traps (Fig. 3). Traps were composed ofgroups sample was placed in a stove for 48 hours and
of four buckets of 20 L each, buried with the its weight was measured soon after. The den-
opening nearby ground level, arranged in a sity of the canopy was measured using a den-
“Y” shape. Each “arm” of the “Y” was 5.0 siometer at 24 points in each area, totaling 96
m from the central point. One bucket was bur- samples. The PBH was measured at 24 points
ied at each tip ofthe “Y” and one at the cen- in each area, totaling 960 trees. To analyze
216 THE JOURNAL OF ARACHNOLOGY
—
Figure 1, 2. Thestylus aurantiurus. 1. Male, 2. Female,
YAMAGUTI & PINTO-DA-ROCHA—ECOLOGY OF THESTYLUSAURANTIURUS 217
few individuals were collected (from 0-2
scorpions/month in 40 traps). Four males were
collected in August, In the three subsequent
months (spring), 18, 36 and 11 scorpions were
collected, respectively (about 80% ofthe total
sampled). Twelve females were collected in
October (about 70% of the total sampled fe-
males). In the remaining months of the year,
— one female was the maximum number cap-
Figure 3. Schematic representation of the drift
fence pitfall traps used in sampling in P. E. Serra tured per month (Fig. 4).
da Cantareira, Brazil. Four pregnant females were found in Oc-
tober and one pregnant female in November
2000. No fecund females were found in the
soil composition, samples were collected at 8 other months. —
points in each area, totaling 32 samples. The Relative abundance in four areas. The
percentage of organic matter and the vegeta- individuals collected possessed a heteroge-
H
tioSntaalticsotviecrailnagnawleyrsies.m—easInurtehde.statistical anal- n—eo1u4s.9d6i6s;trPibu=tio0n.0i0n2)t.heTfhoeurnaurmebaesr(Ko.fW.i,ndi-
&
ysis of the number of animals collected in viduals collected in the two higher areas (1
each area and to verify whetherenvironmental 3) was significantly higher than the number of
factors differ in the four areas, the Kruskal- individuals collected in the two lower areas (2
Wallis test was utilized with a — 0.05. For a & 4) (Mann-Whitney test, U = 79.500; P =
comparison between the number of animals 0.001).
collected in the higher areas and the number The amount of litter was different in the
of animals collected in the lower areas, a four areas (area 1 = 166.9 g, area 2 — 339.1
Mann-Whitney test was used with a = 0.05. g, area 3 = 190.5 g, area 4 — 132.7 g; K.W.,
Before those statistical analysis, the normality H - 18.00; df= 3; P = 0.0004; n = 40), but
and the homogeneity ofvariances were tested. only area 2 presented a different amount of
The data were ranked in both cases. In order litter, the amount of the other three areas are
to verify whether there is a relationship be- very similar (according to the Tukey HSD
tween these factors and the number of col- test). Canopy density was different in the four
lected animals in each area, the Spearman areas (area 1 = 4.625, area 2 = 8.5, area 3 =
Rank Correlation was utilized with n = 4. 8.71, area 4 = 9.92; K.W., H = 22.46; df =
3; P < 0.0001) but it was not related to the
RESULTS/ — number of scorpions collected (r^ = 0.40; n =
Burrows of Thestylus aurantiurus. Indi- 4; P = 0.60). The PBH was also different in
viduals of T. aurantiurus in Parque Estadual the four areas (area 1 = 14.09 cm, area 2 =
Intervales (Sao Paulo, SP, Brazil) were ob- 18.25 cm, area 3 = 16.9 cm, area 4 = 18.86
served foraging at the entrance of their bur- cm; K.W., H = 18.81; df = 3; P = 0.0003)
rows, in ravines near river margins, with ped- but not related to the number ofscorpions col-
ipalps and anteriorbody outside (G. Machado, lected (r^ = 0.21; w = 4; P = 0.79). Soil type
pers. com.), in a typical sit-and-wait foraging was the same in the four areas. The number
type. Burrowing activity of T. aurantiurus ofscorpions collected was not significantly re-
was observed in captivity, where all individ- lated to the elevation (r^ = 0.74; n = 4\ P =
uals constructed many burrows, apparently 0.26). Air temperature and rainfall were not
looking for the best place to stay. The burrows related to abundance, although the number of
were simple, with a single vertical or oblique scorpions increased immediately after the
tunnel (1.5-3.0 cm deep), and a horizontal re- coldest month.
gion at the end (about 1.5 cm long). The en-
DISCUSSION
trance could be circular or semicircular in —
shape, with 1.0-—1.5 cm of maximum width. Reproductive activity. The population of
Seasonality. Thestylus aurantiurus was Thestylus aurantiurus in the Parque Estadual
the only scorpion species recorded in the park. da Serra da Cantareira presents differentiated
Between January (summer) and July (winter). activity throughout the year suggesting the ex-
218 THE JOURNAL OF ARACHNOLOGY
Months 4
.B
&
" temperature Months
# 5
" rainfall
—
Figures 4, 5. 4. Seasonality of the scorpion population of R E. Serra da Cantareira, Brazil (February
2000-January 2001), with the total number ofindividuals collected by month. The columns represent the
number of males and females collected by month. 5. Means of temperature (in °C) and total rainfall (in
millimeters) by month in the P. E. Serra da Cantareira, Brazil (February 2000-January 2001).
istence of a reproductive season. The repro- fertilized females were found in October and
ductive season lasts from September to No- November of 2000.
vember, with an activity peak in October (Fig. Ten of the 12 females collected in October
4), in the beginning of the hot, wet season were collected together with males. These fe-
(Fig. 5). This can be evidenced by the factthat males may have fallen into traps while they
YAMAGUTI & PINTO-DA-ROCHA—ECOLOGY OF THESTYLUSAURANTIURUS 219
were dancing with males in search of a place The collection using pitfall traps produce a
to deposit the spermatophore. The sit-and-wait different result from active collection with ul-
foraging strategy of this species consists of traviolet light. Individuals standing still are
remaining immobile, waiting for prey. This also found with active collection. Ifultraviolet
foraging strategy type does not require the lights were used, the expected number ofcap-
scorpion to move around (Polis 1990a), lead- tured scorpions would be higher and the ex-
ing us to conclude that most of scorpions col- pected number of females would be closer to
lected in this study were in a search of part- the number of males (since the sex ratio of
ners and not prey. Thestylus aurantiurus is 1:1). However, sea-
Corey & Taylor (1987) collected scorpions sonality of activity probably would not be as
in pitfall traps, close to Orlando, Florida, evident as in the collection with pitfall traps.
U.S.A. during one year, sampling every two We conclude that the population of Thestylus
months. Only one species was collected, the aurantiurus in the Parque Estadual da Serra
buthid Centruroides hentzi (Banks 1900). This da Cantareira possesses a reproductive season
is an errant forager but also presenting an in- from September to November (Fig. 4).
crease in activity throughout the year, in July Influence—of environmental factors on
and September, apparently during the repro- abundance. Individuals ofthe Thestylus au-
ductive period. rantiurus population from the Parque Estadual
The reproductive period in scorpions varies da Serra da Cantareira apparently prefer plac-
according to the species. Some South-Ameri- es at a higher elevation. This can be related
can scorpions such as Tityus bahiensis (Perty to the possibility ofshelters in lower areas be-
1833) do not exhibit a well-defined reproduc- ing flooded in the rainy season. The two areas
tive period, instead remaining active through- with a higher number of collected scorpions
&
out the year (Matthiesen 1968). There is in- (1 3) are located at a higher elevation and
formation on several species of the farther from water sources. On the otherhand,
Bothriuridae. The reproductive period of the two areas with fewer collected scorpions
Bothriurus bonariensis (C.L. Koch 1841) is (2 & 4) are located in places at a lower ele-
from November to February, B.flavidus Krae- vation. These areas are close to water sources,
pelin 1911 from November to January, and becoming flooded in the rainy season.
Urophonius iheringii Pocock 1893 and U. According to Polis (1990b), some scorpion
brachycentrus (Thorell 1876) from May to species seek specific environmental conditions
September (Peretti 1997). However, differenc- in which to build their burrows. Namibian
es in the Thestylus aurantiurus reproductive scorpions use several places as a shelter in-
period may be related to climatic differences cluding simple holes in the soil and under tree
at the different localities. The beginning ofthe barks (Lamoral 1979). Harington (1978) ver-
reproductive period of the Argentinean spe- ified that Cheloctonus jonesii Pocock 1892
cies of Bothriurus coincides with the begin- (Liochelidae) examines a large area before be-
ning of the local warm, wet season (Peretti ginning to dig its burrow. Additionally, in
1997). This also occurs in the T. aurantiurus Urodacus there are differences among species
population of the Parque Estadual da Serra da in the choice ofplace, format and structure of
Cantareira and the Parque Estadual da Serra burrows (Koch 1978).
do Japi (Machado & Vasconcellos-Neto Many researchers verified the preference of
2000). For these populations, the beginning of scorpions for higher elevation localities that
the reproductive period is September to Oc- do not flood and are far from water sources.
tober. Williams (1966) observed that burrows ofAn-
There is a great difference in activity be- uroctonus phaeodactylus (Wood 1863) (luri-
tween the sexes in the Thestylus aurantiurus dae) are located on steep slopes, their entranc-
population of the Parque Estadual da Serra da es being counter to surface water flow. These
Cantareira. Many more males were captured burrows are rarely located on the bottom of
than females (Fig. 4), probably due to the in- valleys, in the lower regions ofdrainage. Zin-
&
crease ofmale activity during the reproductive ner Amitai (1969) verified that two species
period. Females wait for males close to their of Compsobuthus Vachon 1949 (Buthidae) of
shelters, which thus explain this low occur- Israel migrate to higher places during the
rence (Benton 2001). rainy season. The entrances to their burrows
220 THE JOURNAL OF ARACHNOLOGY
are also built to avoid the accumulation ofrain World (1758-1998). The New York Entomolog-
water. Koch (1977) also observed that several ical Society. 690 pp.
species of Australian scorpions build their Harington, A. 1978. Burrowing biology ofthe scor-
burrows only on slopes or where rain water pion Cheloctonusjonesii (Arachnida: Scorpioni-
does not accumulate. The individuals ofT. au- d2a4:3-S2c4o9r.pionidae). Journal of Arachnology 5:
rantiurus studied in this work were more Hofer, H., E. Wollscheid, & T. Gasnier. 1996. The
abundant in places at a higher elevation. relative abundance of Brotheas amazonicus
These places are sloping, do not flood and rain (Chactidae, Scorpiones) in differenthabitattypes
water does not accumulate. of a Central Amazon rainforest. Journal of Ar-
achnology 24:34-38.
ACKNOWLEDGMENTS Koch, L.E. 1977. The taxonomy, geographic distri-
We thank Sergio A. Vanin, head of Depar- bution and evolutionary radiation of Australo-
Papuan scorpions. Records of the Western Aus-
tamento de Zoologia of Institute de Biocien- tralian Museum 5(2):83-367.
cias of Universidade de Sao Paulo during Koch, L.E. 1978. A comparative study ofthe struc-
2003, when this study was carried out. We ture, function and adaptation to differenthabitats
thank the colectors of UNIBAN: Arlei Mar- of burrows in the scorpion genus Urodacus
cili, Caroline C. Aires, Cristiane Fojo, Do- (Scorpionida, Scorpionidae). Records of the
menica Palomaris, Fernanda A.N. Bastes, Fer- Western Australian Museum 6(2):119-146.
Lamoral, B.H. 1979. The scorpions of Namibia
nanda Martins, Katia Brozios, Laerte B. Viola,
(Arachnida, Scorpionida). Annals of the Natal
Marcelo Timoteo, Patricia B. Bertola, Roberta Museum 23(3):497-784.
Pacheco, Sandra Favorito and Sidney F. A. Machado, G. & J. Vasconcellos-Neto. 2000. Sperm
dos Santos. We thank Gustavo E. Kaneto, Fla- transfer behavior in the neotropical scorpion
vio H.S. dos Santos, Andre do A. Nogueira, Thestylus glazioui (Bertkau) (Scorpiones: Both-
Alexandre Albuquerque da Silva, Alexandre riuridae). Revista de Etologia 2(l):63-66.
C. Martensen, Felipe B. de Oliveira, Rodrigo Matthiesen, EA. 1968. On the sexual behaviour of
H. Willemart for help in statistical analysis some brazilian scorpions. Revista Brasileira de
and Glauco Machado for help in statistical Pesquisas Medicas e Biologicas l(2):93-96.
analysis and personal communication. We Peretti, A.V. 1995. Analisis de la etapa inicial del
thank Dalmo do V Nogueira Filho, president c(oSrctoerjpoiodnees,BoBtohtrhiruiruursidbaoe)naryiesnusirsel(aCc.iLo.n cKooncke)l
of SABESP, for supplying the data of rainfall reconocimiento sexual. Revue Arachnologique
and temperature. We thank Thayna J. Mello ll(4):35-45.
for assistance in language translation of the Peretti, A.V. 1997. Alternativas de gestacion y
manuscript. We thank Glauco Machado and producion de crias en seis escorpiones argentinos
Alfredo V. Peretti for assistance and revision (Scorpiones: Buthidae, Bothriuridae). Iheringia,
of the manuscript. We also thank the other Serie Zoologia, 82:25-32.
members of LAL: Ana Lucia Tourinho, Jose Polis, G.A. 1990a. Introduction. Pp. 1-8. In The
Biology ofScorpions. (G.A. Polis, ed.). Stanford
Paulo L. Guadanucci, Marcio B. da Silva, University Press.
Marcos R. Hara and Sabrina O. Jorge for as- Polis, G.A. 1990b. Ecology. Pp. 247-293. In The
sistance in completing this project. Biology ofScorpions. (G.A. Polis, ed.). Stanford
University Press.
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