The country of Iran due to its miscellaneous climate is very rich in arachnids
such as scorpions in particular. According to Kovarik (1997) report, there exit
about 32 species of scorpions in Iran. Scorpion stung cases are reported annually
from all over Iran and based upon the reports, 40000-50000 cases of scorpion
stings and various cases led to deaths have occurred annually in our country
(Dehghani and Valaie, 2005). H. lepturus, Androctonus crassicauda
and Mesobuthus eupeus are thought of as the main factors and agents in
scorpion stings, while Buthotus saulcy, Odontobuthus doriae,
Buthotus schach, Olivierus caucasicas and Apistobuthus petrygosercus
are considered as the agents of secondary and minor importance in this respect
in Iran which have been reported sporadically (Dehghani et al., 1998;
Radmanesh, 1990a, 1998). H. lepturus has a yellow/yellow brown color
and a dark stripe on the mesosoma. The length of the male can reach up to 8.5
cm, while the female only reach 5 cm in length. Males have a significantly longer
cauda than females. It was described by Peters in 1861. H. lepturus,
a scorpion reported by Vashon to occur in Iran and Iraq and a member of Genus
with three other species found in the Mid East, was named by Pringle in 1960
as a cause of both local and systemic effects of envenomation in Iraq (Keegan,
1980). H. lepturus among the notable medical species is exceptional in
terms of its dangerous and clinical symptoms. These symptoms appear both topically
and systemically. Radmanesh (1990b) in a survey on scorpion stings, especially
those of H. lepturus species in Khouzestan, has mentioned a 10-15% share
attributed to the above -mentioned scorpion in the province of Khouzestan (Radmanesh,
1990b). This species of scorpion had been responsible for stinging a great number
of people annually in the southern humid and tropical provinces such as Khouzestan
(Dehghani, 2006). Since scorpion sting mortality in Iran is mostly due to H.
lepturus in Khouzestan, thus it can be stated that this creature is the
most dangerous scorpion of Iran, living in Khouzestan province especially on
the east (Dehghani and Valaie, 2004). Which its sting leads to fatal and serious
clinical indispositions such as fatal and acute Hemolysis chronic failure of
the kidney, deep and Necrotic wounds, ankylosis of the joints, permanent and
temporary Psycosis and regular deaths (Radmanesh, 1990b). Apart from therapeutic
matters and provision of antivenin serum which had root in the domain of medicine,
surveying other aspects of scorpions, life such as biology, ecology and toxicologic
studies in different disciplines have been much time-consuming. Therefore, all
the studies conducted should reviewed into the line to find and solve the problem
caused by scorpion sting indisposition (Dehghani, 2006). Because the behavioral
aspects of biology have been less documented and most studies have been anecdotal
in nature, or just have included brief descriptions of biology for different
species (Franke and Jones, 1982; Rein, 2003). One exception is study on birth
behavior and life history of Diplocentrus spitzeri Stanhnke (Franke, 1981).
So, in this study, following the above guidelines, present studies might lead
to the recognition of strong and weak points concerning scorpions in terms of
ecology, biology and other aspect, which ultimately facilitate our ways of control
or prevention from their threat and nuisance. In this study, three fundamental
issues, that is, survey of delivery behaviors, shedding and decision on the
sex of this species of scorpion under laboratory conditions have been discussed.
Study of different biological and behavioral aspects of scorpions in the nature
introduces specific applications, because these creatures comparing other arachnids
are less active outside the barrows and sheltered retreats. On the other hand,
the first step in each region of the country in order to avoid scorpion sting,
in addition to the understanding and familiarity with this arachnids ecology,
is doing studies on the biological behaviors like shedding, delivery and morphological
differences of each species separately. Familiarity with different facets and
aspect of this creature, uncovers their ways of reproduction and their ability
in this regard (Dehghani and Valaie, 2004). With regard to this fact that H.
lepturus is the most dangerous scorpion of Iran and is a native of the countries
of Iran, Iraq and Yemen, then various biological and ecological aspects of this
scorpion must be studied and covered in these countries. Considering the above
cases and the importance of studying the scorpions biological behaviors and
existence of some imperfections in this regard and also due to the attempts
targeted at solving the local problems of Iran, this research was carried out
to survey the biological behaviors of this species in the laboratory during
In this study, the different behavioral components involved in the delivery, shedding and sex ratio were identified and observed and then discussed. The purpose of this study is to present a quantitative analysis of the behavior components involved in biology in H. lepturus (Peters, 1861) from East-west of Iran. in turn, this aids understanding of many other poorly known aspects of scorpion biology.
MATERIALS AND METHODS
This descriptive research was conducted so as to find and distinguish the sex of H. lepturus based on 107 specimens gathered and collected from different towns and counties of Khouzestan province during six expeditions across rural and urbane regions such as Baghmalek, Izeh, Radmermaz, Shush, Ahvaz, Hamidieh in August, October, November, February, March and April of years 2001-2002. The collected specimens were all sent to the laboratory to distinguish the species precisely and after putting them dead in the 70% ethyl alcohol and exact decision on their species using a criterion considering all morphological parameters and by the use of stereo microscope, their abdominal pectine denticles were counted. To peruse the biological behaviors, 50 H. lepturus specimens which were fed and kept in capped bottles were studies while their way of shedding and number of newly-born young were also investigated under laboratory conditions in the process. Collected data from the biological behaviors such as shedding and delivery along with the information about the count of abdominal pectine denticles were all recorded and presented through statistical and descriptive tables.
Results obtained from sex ratio in H. lepturus: The research revealed that in 107 H. lepturus specimens, 27 specimens (23%) were male and 80 ones (77%) were female. Distinguishing between the male and the female was made by counting the number of abdominal pectine denticles which were 9-12 and 14-16 in females and males, respectively. By exerting the bisexual method in 107 specimens of H. lepturus, 21 cases were long-tailed (19.5%), that is, male and the rest 86 cases (80.5%) were female (Table 1 and Fig. 1).
||Total No. and percentage of female and male H. lepturus
based on method of distinguishing
||Bisexuality in male and female H. lepturus
||H. lepturus coming out of the old cuticule
||5 old-shed H. lepturus in full
Results acquired from H. lepturus shedding: At the beginning of shedding, the cuticule is broken apart at the joining point of carapace and the sides and then the chelicerae are driven out of the old cuticule. As the pedipalps come out of the old cuticule, carapace is driven upwards following the contraction made in the scorpions body. With the continuation of the contractions, pedipalps, legs and the tail come gradually out of the cuticule. the body at this moment gets so soft and jellied (Fig. 2).
Duration of shedding for the specimens under survey lasted for about 4-6 h (Fig. 3). The newly-shed H. lepturus appears dark only in the lateral and median eyes and at the end of the tail, while other parts of the body such as a abdomen, legs, chelicerae, pedipalps, tail and interior surface of the pedipalps remain colorless.
The body in this way is entirely soft and the scorpions motions is too
slow. Because of the softness of the claws and legs, the scorpion moves so slow,
nevertheless it reacts to the finger motion of human begin and the object, but
does not drive its telson to sting. Melanization is also relative slow under
laboratory conditions in H. lepturus and takes a 10-30 day period so
that the color of the newly-born scorpion goes like the other scorpions. Softness
of the body of the newly-born scorpion is clearly distinguishable after 2-3
days. The new cuticule is brownish yellow and in the pedipalps it is dark born.
||Observation on the H. lepturus shedding based on time
(month, day, night)
The results gained from 50 scorpions kept in the laboratory showed that only 10 cases (20%) had shed. Among these cases one cases was male. in the other cases, they were all female or not reached maturity yet. 6 cases of the sheddings (60%) and the rest four (40%) had occurred in August and September respectively (Table 2).
Results obtained from H. lepturus delivery: Gestation period for H. lepturus is not evidently known. But scorpions in a certain season manifest their mating manifestations. In the body of a pregnant H. lepturus, the young are seen perfectly arranged side by side especially by the sides. Abdominal segment have been totally parted from one another from the back and the sides so that the view of the young's whiteness in the back, has given a distinct appearance to the scorpion. In this condition, the Tergites (dorsal segments) have born white and brown spots on them. Delivery is not successfully done in all cases and on some occasions, although the young has half come out of the genital opening, the mother has not been successful to undergo and terminate its delivery and has died in the process (Fig. 4).
While delivering, the space between carapace and the abdomen is partly contracted so that the genital opening and the pectines are distinctively pressurized to keep the pectines in an angular position with the abdomen. At the time of delivery, the tail comes out of the genital opening first. After the appearance, the tail moves incessantly to and fro. Sometimes two tails related to two young come out the genital opening simultaneously that only one succeeds to emerge and the other, comes out immediately. The last parts coming out of the mothers body are the pedipalps (Fig. 5).
Delivery is facilitated by the young's motion sideways and the mothers contraction.
Duration of emergence varies in each young from 10-20 min and delivery lasts
approximately for 4-6 h. The young are piled up between mothers folded
legs, called as birth basket and the chelicerae from the very beginning, but
then mother stimulates them by her pedipalps to direct them from different parts
of the body (pedipalps, legs, abdomen and tail) to her back. this process continues
until the last young is climbed to the mothers back (Fig. 6).
||A gestated H. lepturus
||Emergence of a H. lepturus young
||H. lepturus with young on her back
The results of the study demonstrated that out of 50 H. lepturus, 42 cases were female. Among their number, 16 cases were with young which 14 case of them had successful birth, while two case of them had died prior to or at the very beginning of the delivery due to some indefinite reasons. Their abdomens were entirely swollen and the young within were thoroughly distinguishable (Table 3).
||Total No. and percentage of female H. lepturus based
on delivery process
|Values in parentheses shows percentage
||Observation on the distribution of delivery process in H.
lepturus based on time
It was concluded that the time of delivery in H. lepturus is definitely fixed during the year which lasted from 15 August to 25 September, that is about one month and a half in the studied cases. in the rest month of the year, despite the sameness of temperature in the laboratory, no other delivery was observed. Out of the fourteen deliveries already mentioned, 4 cases (28-5%) and the rest (71.5%) had taken place in daytime and nighttime, respectively (Table 4). Duration of delivery varied 4-6 h approximately. the average number of the young born was 24.3 in each delivery.
The results revealed that the average number of young born in each delivery in H. lepturus had been 24.3. Farzanpey (1987), regarding the number of the scorpions young points out that the number is variable in each species ranging from 6 to 90 young (Farzanpey, 1987). Kamali (1984) has reported a 20-60 range of number in each species which has sometimes been more (Kamali, 1984). Franke (1981) has reported the number of the young in Centruoides gracilies from 22 to 91 ones in different countries (Franke, 1981). Vazirianzade (1990) has given a distinctive count of 35 and 38 in the number of H. lepturus young differently (Vazirianzadeh, 1990). The differences observed in the number of young born in each delivery in H. lepturus are most likely species related because the environmental conditions used for this study were similar to the environmental conditions used in other studies. All the above studies were conducted laboratory.
The survey showed that out of 107 cases of H. lepturus, 27 (23%) were male and 80 (77%) were female. Counting the number of pectine denticles was managed as a parameter, varying in both sexes of H. lepturus for distinguishing between the male and the female totaling 9-12 and 14-16 in them, respectively. Farzanpey (1987) has declared the number of the pectine denticles in the above-mentioned scorpion as 12-16 in the male and 8-11 in the female (Farzanpey, 1987). Vazirianzadeh (1990) has reported the number of the pectine denticles in the H. lepturus as 8-11 and 12-16 in female and male, respectively which in accordance with the results achieved in this study (Vazirianzadeh, 1990). Levi and Amitai (1980) believed that the number of pectine denticles in the males are more than the females (Levy et al., 1980). A vast variety of different species have been studies in view of their number of pectine denticles. Another way of distinction has been applied on the basis of the exterior shape and bisexuality which is only applicable after full maturation. In this way, long tails of the males are clearly distinguishable from those of the females. By applying the bisexual method, out of 107 specimens of H. lepturus, 21 (19.5%) were long-tailed, that is male and the rest 86 specimens (80.5%) were totally female. Levy and Amitai (1980) reported that the body males are more slender that the female (Levy et al., 1980). It can be inferred that the difference in the number of both methods, is something related to the immature male scorpions still under going their formal development.
In this way, the scorpions sex can be distinguished easily without touching it. In sum, the results obtained demonstrate that due to the unavailability of urgent anatomy of the scorpion, probing the genital pores in the males and studying the other morphological traits applicable in distinguishing between the sexes, counting the abdominal pectine denticles is a relatively convenient and reliable way to the final distinction of the sexes in this scorpion before maturation without causing serious harm to it.
Vazirianzadeh (1990) has reported one case of shedding in the H. lepturus species in which the scorpion behaves so placidly for ten days as from the shedding and does not react to the mechanical stimulus (Vazirianzadeh, 1990). This is in accordance with our findings. Eating her own young is one of the outstanding characteristics attributed to H. lepturus which is proved by a 50% report of eating the young by their mother under laboratory conditions. Among those, without tendency to eat their young, the first shedding of the young occurred ten days after their birth. It seem that H. lepturus comparing other specie is more prone to eat her young which laboratory conditions may be the most contributory factor in this respect.
The results of present study demonstrate that H. lepturus can be reared successfully in the laboratory. Knowledge of the laboratory biology of this species will enable future studies to be conducted. Additional studies should be attempted to understand how other temperature, humidity and photoperiod regimens could effect the developmental cycle of H. lepturus and how these parameters could affect the Biologic behaviors.