ECOLOGY OF THESTYLUS AURANTIURUS OF THE PARQUE ESTADUAL DA SERRA DA CANTAREIRA, SA O PAULO, BRAZIL (SCORPIONES, BOTHRIURIDAE)

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2006. The Journal of Arachnology 34:214–220

ECOLOGY OF THESTYLUS AURANTIURUS OF THE PARQUE
ESTADUAL DA SERRA DA CANTAREIRA, SÃO PAULO,
BRAZIL (SCORPIONES, BOTHRIURIDAE)

Humberto Y. Yamaguti and Ricardo Pinto-da-Rocha: Departamento de Zoologia,
Instituto de Biociências, Universidade de São Paulo, Caixa Postal 11461, CEP
05422-970, São Paulo, SP, Brazil. E-mail: humbertotete@yahoo.com.br

ABSTRACT. Individuals of a Thestylus aurantiurus Yamaguti & Pinto-da-Rocha 2003 population in
the Parque Estadual da Serra da Cantareira (São Paulo, SP, Brazil) show an increase of activity 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 of the 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, scorpions 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), Jundiaı́, 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. Höfer 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 of some 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 THESTYLUS AURANTIURUS 215

The study presented here was conducted to tral point. Strips of canvas of 5.0 ⫻ 0.5 m,
assess the activity of a population of Thestylus fixed with wooden stakes, connected each out-
aurantiurus (Figs. 1 & 2) throughout the lying bucket to the central one in order to 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
Parque Estadual da Serra da Cantareira, São trap was 20 m 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 Núcleo Pedra Grande of the 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), São 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 São Paulo (UNIBAN). erected to capture small mammals alive, a pre-
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 higher than the ob-
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 of seasonality
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.
São Paulo and Mairiporã. 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 of monthly median temperatures São Paulo (MZSP), São 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: amount of lit-
neamento Básico do Estado de São Paulo ter, density of the canopy, perimeter of closest
(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 of Mairiporã, near to the were recorded on the same day, in May 2002
Parque Estadual da Serra da Cantareira. (subsequent to the period of collection), close
Ecological samplings.—Twelve monthly to the places where traps were located. The
collections, of nine days each, were undertak- amount of litter of an area of 0.25 m2 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 of groups 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 of the ‘‘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 THESTYLUS AURANTIURUS 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% of the 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-
tional covering were measured. neous distribution in the four areas (K.W., H
Statistical analysis.—In the statistical anal- ⫽ 14.966; P ⫽ 0.002). The number of indi-
ysis of the number of animals collected in viduals collected in the two higher areas (1 &
each area and to verify whether environmental 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 ␣ ⫽ 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 ␣ ⫽ 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 of variances 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 (rs ⫽ 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 (São 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 of scorpions col-
ipalps and anterior body outside (G. Machado, lected (rs ⫽ 0.21; n ⫽ 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 of scorpions collected was not significantly re-
was observed in captivity, where all individ- lated to the elevation (rs ⫽ 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-
trance could be circular or semicircular in DISCUSSION
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

  Figures 4, 5.—4. Seasonality of the scorpion population of P. E. Serra da Cantareira, Brazil (February
2000–January 2001), with the total number of individuals 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 fact that     males may have fallen into traps while they

YAMAGUTI & PINTO-DA-ROCHA—ECOLOGY OF THESTYLUS AURANTIURUS 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. If ultraviolet
foraging strategy type does not require the lights were used, the expected number of cap-
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 of the 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 of shelters 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 other hand,
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 of the 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 of place, 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 of An-
There is a great difference in activity be- uroctonus phaeodactylus (Wood 1863) (Iuri-
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 of drainage. Zin-
crease of male 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 of rain        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 of the scor-
                                                        pion Cheloctonus jonesii (Arachnida: Scorpioni-
burrows only on slopes or where rain water
                                                        da: Scorpionidae). Journal of Arachnology 5:
does not accumulate. The individuals of T. au-          243–249.
rantiurus studied in this work were more              Höfer, 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 different habitat types
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-
                                                        bution and evolutionary radiation of Australo-
   We thank Sergio A. Vanin, head of Depar-             Papuan scorpions. Records of the Western Aus-
tamento de Zoologia of Instituto de Biociên-           tralian Museum 5(2):83–367.
cias of Universidade de São Paulo during             Koch, L.E. 1978. A comparative study of the struc-
2003, when this study was carried out. We               ture, function and adaptation to different habitats
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. Bastos, Fer-            Western Australian Museum 6(2):119–146.
                                                      Lamoral, B.H. 1979. The scorpions of Namibia
nanda Martins, Kátia Brózios, Laerte B. Viola,
                                                        (Arachnida, Scorpionida). Annals of the Natal
Marcelo Timóteo, Patrı́cia 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, Flá-           transfer behavior in the neotropical scorpion
vio H.S. dos Santos, André do A. Nogueira,             Thestylus glazioui (Bertkau) (Scorpiones: Both-
Alexandre Albuquerque da Silva, Alexandre               riuridae). Revista de Etologia 2(1):63–66.
C. Martensen, Felipe B. de Oliveira, Rodrigo          Matthiesen, F.A. 1968. On the sexual behaviour of
H. Willemart for help in statistical analysis           some brazilian scorpions. Revista Brasileira de
                                                        Pesquisas Médicas e Biológicas 1(2):93–96.
and Glauco Machado for help in statistical
                                                      Peretti, A.V. 1995. Análisis de la etapa inicial del
analysis and personal communication. We                 cortejo de Bothriurus bonariensis (C.L. Kock)
thank Dalmo do V. Nogueira Filho, president             (Scorpiones, Bothriuridae) y su relación con el
of SABESP, for supplying the data of rainfall           reconocimiento sexual. Revue Arachnologique
and temperature. We thank Thayná J. Mello              11(4):35–45.
for assistance in language translation of the         Peretti, A.V. 1997. Alternativas de gestación y
manuscript. We thank Glauco Machado and                 produción de crı́as en seis escorpiones argentinos
Alfredo V. Peretti for assistance and revision          (Scorpiones: Buthidae, Bothriuridae). Iheringia,
                                                        Série Zoologia, 82:25–32.
of the manuscript. We also thank the other
                                                      Polis, G.A. 1990a. Introduction. Pp. 1–8. In The
members of LAL: Ana Lúcia Tourinho, José              Biology of Scorpions. (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 of Scorpions. (G.A. Polis, ed.). Stanford
                                                        University Press.
              LITERATURE CITED                        Polis, G.A. & S.J. McCormick. 1986. Patterns of
Benton, T. 2001. Reproductive ecology. Pp. 278–         resource use and age structure among a guild of
  301. In Scorpion Biology and Research. (P.            desert scorpions. Journal of Animal Ecology 55:
  Brownell & G.A. Polis, eds.). Oxford University       59–73.
                                                      Williams, S.C. 1966. Burrowing activies of the
  Press.
                                                        scorpion Anuroctonus phaeodactylus (Wood)
Corey, D.T. & W.K. Taylor. 1987. Scorpion, pseu-
                                                        (Scorpionida: Vejovidae). Proceedings of the
  doscorpion, and opilionid faunas in three central
                                                        California Academy of Sciences 34(8):419–428.
  Florida plant communities. Florida Scientist
                                                      Zinner, H. & P. Amitai. 1969. Observations on hi-
  50(3):162–167.                                        bernation of Compsobuthus acutecarinatus Si-
Farley, R. 2001. Structure, Reproduction and De-        mon and C. schmiedeknechti Vachon (Scorpion-
  velopment. Pp.13–78. In Scorpion Biology and          idea, Arachnida) in Israel. Israel Journal of
  Research (P. Brownell & G.A. Polis, eds.). Ox-        Zoology 18:41–47.
  ford University Press.
Fet, V., W.D., Sissom, G. Lowe, & M.E. Braun-         Manuscript received 30 June 2004, revised 26 Jan-
  walder. 2000. Catalog of the Scorpions of the         uary 2005.

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