Distribution of Neoscorpiops scorpions in the Western Ghats of Maharashtra and Gujarat and possible trichobothridial variations among isolated population

11 Pages·1997·6.2 MB·

by  D B Bastawade

DISTRIBUTION OF NEOSCORPIOPS SCORPIONS IN THE WESTERN GHATS OF
MAHARASHTRA AND GUJARAT AND POSSIBLE TRICHOBOTHRIDIAL VARIATIONS
AMONG ISOLATED POPULATIONS
1
D.B, Bastawade2
(Withforty seven text-figures)
Introduction commonly reported from the Indian Himalayan
ranges, right from Kashmir to Arunachal Pradesh.
Though the placement of the subfamily However, the sub-genusEuscorpiops is observed to
Scorpiopsinae under family Vaejovidae is doubtful restrict itself to the North Eastern portion of India,
(Stahanke 1974, Francke 1976) so far all Southeast Bangladesh, Bhutan and Burma (Bastawade 1992)
Asian Scorpiops are placed under the same family and the sub-genus Alioscorpiops to Burma only
Vaejovidae. Thesubfamily Scorpiopsinae comprises (Francke 1976). Thesub-genusScorpiops(Nominal)
three genera, namely 1. Scorpiops Peters (1861), 2. is widely distributed throughout the Himalayas and
Parascorpiops Banks (1928) and 3. Dasyscorpiops also at certain places in Satpura such as Pachmarhi,
Vachon (1973). Francke (1976) doubted the Madhya Pradesh (Bastawade 1992), (See Fig. 1 &
taxonomic validity of the latter two and suggested 2). The subgenus Neoscorpiops shows restricted
that they be lowered to subgeneric rank under distribution through the Western Ghats in
Scorpiops. He also suggested the revision of the Maharashtra and Gujarat (some data unpublished).
taxonomic status of the sub-family Scorpiopsinae This subgenus is so far known to comprise only three
itself. Recently Kovarik (1995) raised thesub-family nominate species viz. 1. Scorpiops (Neoscorpiops)
Scorpiopsinae to the rank of family Scorpiosinidae satarensis Pocock (1900) (Mahabaleshwar, Satara),
and included all the species known from SE Asia 2. S. (N) deccanensisTikadtx and Bastawade (1976)
under this family. The genus Scorpiopsrepresents a (Sinhagad, Pune) and 3.S. (N.)tenuiacauda Pocock
vast distribution right from Afghanistan to Burma (1900) (Matheran, Raigad). These species occur in
through the Great Himalaya and at some places in three adjacent districts in the state of Maharashtra
Satpura and western ghats in south India (Bastawade (Fig. 2).
1992). This genus comprises 15 species and 7 After Fauna ofIndia: Scorpions (Tikader and
subspecies nominated so far from India. Whereas the Bastawade 1983), I undertook an extensive survey
remaining two genera are monotypic and so farknown of the Western Ghats for the collection of
to occur only at one placeeach asParascorpiopsfrom Scorpions during 1984-87. The intense effort of
Borneo, Indonesia andDasyscorpiops from Malacca, these surveys made it possible to collect Scorpiosinid
Malaysia (Francke 1976). Scorpions from as many as 20 new localities in
The major genus Scorpiops Peters has been Western Ghats in different districts (Bastawade
revised and divided into four sub-genera, namely i. 1986, 1987). The collection areas spread over 6
Scorpiops Vachon (Nominal), ii. Neoscorpiops districts between Tapi and Koyana valleys of
Vachon, iii. Euscorpiops Vachon and iv. Alios Maharashtra. The only district in Gujarat state
corpiops Vachon (Vachon 1980). Among these, from which these Scorpions are reported is Dangs,
exceptNeoscorpiops, the remaining threehave been which also falls to the south of Tapi Valley. The
records of this family from Dhulia, Nasik, Thane
‘Accepted June, 1995.
2Zoological Survey of India, Western Regional Station, districts in Maharashtra and Dangs in Gujarat are
1182/2, Fergusson College Road, Pune 411 005. new.
DISTRIBUTION OF NEOSCORPIOPS SCORPIONS IN THE WESTERN GHATS 105
PART OF MAHARASHTRA
V MAP SHOWiNG DISTRIBUTION OF
FAMILY VAEJOVIDAE AND ITS GENUS
S
AND SUB GENERA
DISTRIBUTION OF FAMILY VAEJOVI0AE
ft
GENUS SCORPIOPS PETERS
DISTRIBUTION OF SUB GENUS SCORPIOPS
PETERS
DISTRIBUTION OF SUB GENUS NEOSCORPIOPS
VACHON
DISTRIBUTION OF SUB GENUS EUSCORPIQPS
VACHON
MAP SHOWING DISTRIBUTION OF THREE GROUPS OF TYPE LOCALITY 6 DISTRIBUTION OF SCORPIOPS
SUBGENUS NEOSCORPIOPS IN MAHARASHTRA d la£gHPIQPS> PACHMARHICUS SP NOV
GUJRAT
Fig. 1. Showing distribution of family Scorpiopsinidae and its genera and subgenera;
2. Showing distribution of three groups of subgenus Neoscorpiops in Maharashtra and Gujarat
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.
DISTRIBUTION OF NEOSCORPIOPS SCORPIONS IN THE WESTERN GHATS 107
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DISTRIBUTION OF NEOSCORPIOPS SCORPIONS IN THE WESTERN GHATS 109
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DISTRIBUTION Of NEOSCORPIOPS SCORPIONS IN THE WESTERN GHATS
111
Materials and Methods Dagadpada, Birdipada, Saptashringi, Hathgad,
Dholapgad, Kathiwadapada and Hadakaichond,
The hilly terrain ofWestern Ghats was visited district Nasik; Jowar Mokhada, district Thane;
and particular spots were selected to prise out the Kondaibari Ghat, districtDhulia in Maharashtra and
Scorpions ofthe sub-genusNeoscorpiops. As these Ahwa in Dang district, Gujarat State.
Scorpions are known to be lithophilous and
rupicolous in nature, they occur more often in the Results and Discussion
cracks and crevices of the outcrops of natural hard
rocks as well as in artificially cut road sides. Such The hilly terrain of Western Ghats in
rocks were located andbroken carefullywith the help Maharashtra and Gujarat shows a peculiar example
of a flat trowel, hard and sharp crowbars. This oflimited distribution forScorpions ofthe subfamily
method proveduseful in getting agood yield ofthese Scorpiopsinae Scorpiopsindae. The distribution of
Scorpions from the road side rocks, more than from this sub-family is almost restricted to some pockets
natural rocks. in Western Ghats between Tapi Valley in the North
The specimens thus collected were directly and Koyana Valley in South (Figs. 1 & 2). It is also
preserved in 70% rectified spirit, precisely labelled observed that these scorpions are distributed through
indicating all the essential collection data, registered hilly, comparatively humid areas and due to the
with Zoological Survey ofIndia, Western Regional heavy destruction of forests they are now inclined
Station, Pune for unidentified Zoological Specimens to be restricted to certain pockets in Western Ghats.
in invertebratesection. Such specimenswerestudied Thedetailed studies oftrichobothridial patterns
CZ
wet under a binocular for morphological as well in thedifferent sets on external surface oftibial digit
as trichobothridial details. The studies of ofpedipalp viz. eh (1-5), esh (1-2), em (1-2), est (1-
trichobothridial patterns on the pedipalps were 9) and et (1-7) and the ventrals (16) (Vachon 1980)
compared between different forms. The show the nature of constant similarities in the
diagrammatic representations were made with help composition ofsets oftrichobothries. Similarly, the
oftubular camera lucida on the samebinocular. The trichobothries show some differences in the relative
trichobothridial patterns on the external and ventral positions within the sets as in Figs. 3-47. The
surface ofthe tibial segment ofpedipalp and also on trichobothries present in the setseh, eshandem (i.e.
themanus and immovable finger ofpedipalp foreach eb 1-5, est 1-2 and em 1-2) in the specimens studied
specimen were studied for moredetails and analysed also show the sameconstantnumbers as thosepresent
to segregate the different groups. Emphasis was in thespecies ofthe two other known subgenera from
given to the sets on external surface oftibia, manus north and north-east India (Vachon 1980). The
and immovable finger, ventral surface of tibia and trichobothries present in the sets est and et show
dorsal surface of manus ofpedipalp. differences in respective numbers and in their
The present communication deals with the placements. The ventrals (V) show differences in
distribution, status and variation in trichobothridial numbers only. The Eb and Dt on the manus also
patterns among the different units of Neoscorpiops exhibit differences in their inter-relationary
population in Western Ghats of Maharashtra and placements as in text Figs. 5, 8, 11...47.
Gujarat and also investigates the possibility of The trichobothridial patterns on tibia, manus
isolation within this population due to the and immovable fingers ofpedipalps are considered
degradation of floral components once keeping it as one of the strong and stable morphological
together. characters to distinguish the families, genera and
Duringrecent surveys (1948-87)Neoscorpiops subgenera in Scorpions (Vachon 1973, 1975, 1980).
have been collected from Mulsi (donated) and The sub-family Scorpiopsinae possesses the
C
Bhimashankar, district Pune; Pandav leni, Waghera, triehobothridal pattern of ‘TYPE (Vachon 1973,
N
112 JOURNAL, BOMBAY NATURAL HIST. SOCIETY, Vol. 94 (1997)
Table
1
SHOWING AFFINITIES AND DIFFERENCES IN THREE SUBGENERA OFTHEGENUS SCORPIOPSPETERS
SCORPIOPSINIDAE)
(F:
Characters Manus Manus Veside Veside An annular Total No. of No. of No. of No. of
V
wider longer wider longer ring at the No. of tricho- tricho- tricho- tricho-
than than than than base of Tricho- bothries bothries bothries bothria
long wide long wide veside bothria in et set in est set on exter- on tibia
on tibia on tibia nal medium
line in
est set
Names of Subgenera 1 2 3 4 5 6 7 8 9 10
Scorpiops 60% 40% 60% 40% Absent 54-62 Always 4 4 Always 2 6-13
Neoscorpiops 00% 100% 00% 100% Absent 67-73 Always 6 6-11 vary bet. 12-17
2-4
Euscorpiops 00% 100% 00% 100% Always 55-60 Always 5 4-5 Always 2 7-9
Tikader and Bastawade 1983). The type genus It was necessary to modify the pattern of the
Scorpiops Peters has been divided into four sub- trichobothriotaxypresented by Vachon (1980) toeb
genera as mentioned earlier, mainly on the basis of 1-5, est 1-2, em 1-2, est 1-6 to 1-11 and et 1-6 (Figs.
total number oftrichobothries in the setsest, et, and 3, 6, 9...45) (See Table II). Vachon (1980) has not
v on tibia and some other important morphological mentioned V. (ventrals) on tibia (patella) which vary
characters such as telson (Vachon 1980). Present from 12 to 16 in present observations (Figs. 4-7-
observations further reveal that the subgenus 10...46). Trichobothria eb 3 placed always distal to
&
Neoscorpiops (Tikader Bastawade 1983, Figs. esbon external surface ofmanus (Figs. 5-8-11 47).
...
1069-1128) shows more affinities to the sub-genus There seems be no relevant significance in its
&
Euscorpiops (Tikader Bastawade 1983, Figs. placement ofeb 3 placed too close or too far away
1247-1305) than to the stalk sub-genus Scorpiops from either on external surface or toDron dorsal
&
(nominal) (Tikader Bastawade 1983, Figs. 1129- surface on manus (Figs. 5-8-11...47). There are
1246) See Table I. always 4 V (ventral) trichobothries on manus (not
The present observations (Figs. 3-47) allow illustrated), db on immovable finger always placed
us to suggest appropriate modifications for the at thebase (not shown in all thepresentillustrations).
trichobothriotaxy proposed by Vachon (1980) as Vachon (1980) discussed the nature of
eb 1-5, esb 1-2, em 1-2, est 1-7 to 1-10 and et 1-5 to asymmetry and variation in trichobothridial patterns
1-7 on external surface oftibia (patella) ofpedipalp. in the genus Scorpiops Peters. He also emphasised
His observations were based on the types of and synthesised the definite nature ofthese patterns
Scorpiops {Neoscorpiops) satarensis Pocock and S. and utilised them as one of the stronger characters
( .) tenuiacauda Pocock, probably on a few in Scorpion taxonomy along with the other
specimens. These observations arenow re-examined morphological characters as the basis. The modified
for a larger number of Neoscorpiops specimens, trichobothridial pattern for the subgenus
recently collected from many new localities from NeoscorpiopsVachon minimises thevariationsin the
Western Ghats in Maharashtra and Gujarat as set et and gives scope to consider set est as one of
mentioned earlier. thecharacters tobeutilised for taxonomic importance
DISTRIBUTION OF NEOSCORPIOPS SCORPIONS IN THE WESTERN GHATS 113
Table 2
SHOWING AFFINITIES AND DIFFERENCES IN THREEPOPULATION UNITS OF THE SUB-GENUS
NEOSCORPIOPSVACHON SCORPIOPS SCORPIOSINIDAE)FROM WESTERN GHATS
( :
Characters Trichobothriotaxies on tibial digit ofPedipalp
Occurrence Preferential
Population eb esb em est mediuan est along et V in Western humidity
Units exterior carina Ghats
I 5 2 2 1 to 6-7 always 2 6 12-13 Lower altitude Less humid and hot
II 5 2 2 1 to 8-9 always 3 6 12-15 Medium altitude Medium humid and warm
III 5 2 2 1 to 10-11 always 4 6 15-16 Higher altitude Much humid and cool
along with total number ofventral (V) trichobothries Interestingly, the Scorpion subgenus Neoscorpiops
on ventral surface oftibia (patella). is limited to the south ofTapi Valley in the north and
North of Koyana Valley in the south in Western
Comments Ghats (Map 2). As the species of to Mollusca, this
Scorpion subgenus is so far unknown beyond these
TheWestern Ghats was once acontinuous strip limits.
of semi-evergreen to deciduous forests (Mani 1968). The genus Scorpiops Peters in course of
Due to the enormous human activity and evolution has diverged into three separate subgenera
interference, under the name ofdevelopment, much among Indian species. The subgenus Scorpiops
of the forest cover has now been depleted. Most of Vachon retains thebasic trichobothridial pattern and
the places once under forest cover and connected the numbers as in the stalk genus Scorpiops Peters.
through floral agencies, have now been cut offfrom The two other sub-genera namely Euscorpiops
each other, though not yet completely. Vachon and Neoscorpiops Vachon show change in
Such destructive activitieshaveaffected faunal this character. The pattern, number and placements
life and created obstructions which limit the of the trichobothries, at least in two sets namely et
movements of fauna, specially the ground dwelling and est have changed. The original number of
invertebrates such as Scorpions, which mostly have trichobothries 4 et 4 est sets in Scorpiops Vachon
,
nocturnal life conditions and are true ground have changed to 5 et 4-5 est sets in Euscorpiops
,
dwelling creatures. Their spatial movements within and6 et 6-11 est sets in Neoscorpiops respectively
,
population units are basically very limited. Due to (See Table I). Such change is more prominent in the
these conditions the high altitude places (peaks) of est set for subgenus Neoscorpiops Vachon, which
Western Ghats exhibit a typical case offormation of further shows some isolation trend in each unit
smaller units of suitable habitat for Neoscorpiops among the existing population in Western Ghats of
population now partly and partially isolated from Maharashtra and Gujarat. The trichobothries present
each other, particularly at places such as on the external surface of tibia (patella) in est set
Mahabaleshwar, Sinhagad, Matheran, along the median external carina observed to be
Bhimashankar, Brahmagiri and Saptashringi, etc. considerably stablein topographically isolated forms
&
Subba Rao Mitra (1979) state that “type of the subgenus Neoscorpiops. These exhibit three
localities for 16 species (Mollusca) recorded fall units having only 2 est trichobothries on external
within the Pune district and the majority ofthem are median carina (Fig. 3, 6 & 9), 3 £5/(Figs. 12, 15, 18,
recorded from hill streams near Khandala. All these 21, 24, 27, 30, 33 & 36) and 4 est (Figs. 39, 42 &
species have arestricted range ofdistribution in the 45). The unit 3 est trichobothries seems to be more
Western Ghats, and are not known beyond it.” common and widely distributed than the remaining