Journal of
Threatened Taxa | www.threatenedtaxa.org | 26 June 2018 | 10(7):
11955–11962
First definitive record of a whip scorpion Labochirustauricornis (Pocock, 1900) from Goa, India: with
notes on its morphometry and pedipalp micro-morphology
Manoj Ramakant Borkar
School of Arachnology, Biodiversity
Research Cell, Department of Zoology, Carmel College for Women (Affiliate of
Goa University), Nuvem, Goa, India
borkar.manoj@rediffmail.com
doi: http://doi.org/10.11609/jott.4084.10.7.11955-11962 | ZooBank: urn:lsid:zoobank.org:pub:7A722B0F-647F-48C7-84C5-5457F308760E
Editor: D.B. Bastawade, Pune, India. Date
of publication: 26 June 2018 (online & print)
Manuscript details: Ms# 4084 | Received 15 February 2018 | Final received 06 March 2018 | Finally
accepted 20 June 2018
Citation: Borkar, M.R. (2018).First definitive record
of a whip scorpion Labochirus tauricornis (Pocock, 1900)
from Goa, India: with notes on its morphometry and pedipalp micro-morphology. Journal
of Threatened Taxa 10(7): 11955–11962; http://doi.org/10.11609/jott.4084.10.7.11955-11962
Copyright: © Borkar 2018. Creative Commons Attribution 4.0 International License. JoTT allows unrestricted use of this article in any medium,
reproduction and distribution by providing adequate credit to the authors and
the source of publication.
Funding: There was no funding for the present work.
Competing interests: The author declares no competing interests.
Acknowledgements: The author expresses gratitude
to Dr. Rahul Mohan, Senior Scientist, National Centre for Antarctic and Ocean
Research (NCAOR); for providing Scanning Electron
Microscopy facilities at NCAOR, Bogda Goa. Technical
assistance with sample processing for SEM rendered by Sahina Gazi, Scientific Assistant, NCAORis much appreciated. Valuable inputs on field botanical data of the study area
have been spared by Shri PrakashD. Salelkar, Range Forest Officer, Mhadei Wildlife Sanctuary, Goa.
Appreciation is also due to author’s students Leona Fernandesand Ann Merin Dominic at the Biodiversity Research
Cell, Carmel College for Women, Nuvem Goa; for assistance in field and laboratory.
Abstract: Bastawade & Borkarin 2008 made a passing reference to the presence of a single uropygid species in Goa, though without much primary
diagnostic data on the collected specimen of four females. The present study puts in place a
definitive record of the uropygid, Labochirus tauricornis Pocock, (1900) in the state of Goa, and addresses an
important gap in our understanding of its occurrence, morphology, and ecology.
Besides documenting the species of this cryptozoic, nocturnal arachnid predator
commonly known as ‘Vinegaroon’ on account of their
vinegary allomone spray; the present study also
describes the gross morphology , morphometryand micro-morphology of non-ambulatory sub-raptorial pedipalpswhich are of taxonomic-diagnostic value, elucidated using scanning electron
microscopy, in addition to routine stereomicroscopy. The paper also examines in
detail, sexual dimorphism and morphometry of this uropygid species.
Keywords: Scanning electron microscopy, sexual
dimorphism, taxonomy, uropygid, whip scorpion.
As for
whip scorpion diversity, 103 species under 16 genera have been reported
worldwide (Harvey 2002, 2003). Currently 83 species of whip scorpions have been brought on record
from the Asian continent, making it the most diverse region of the world for uropygid diversity (Harvey 2003). The Indian subcontinent is home to 19
species in six genera (Pocock 1900). As of now only six species of whip
scorpions under four genera have been described from
India (Bastawade 1988). Among the Indian states, the uropygids have been so far reported from Assam, Karnataka,
Meghalaya, Tamil Nadu, West Bengal (Pocock 1900),
Maharashtra (Bastawade 1988), Goa (Bastawade & Borkar 2008),
Andhra Pradesh (Javed et al. 2009), and Chattisgarh (Sharma & Chandra 2012).
The extant records of number and
distribution of whip scorpion species clearly suggest gaps in our understanding
of the global and Indian uropygid diversity, and
underpins the need to have more exploratory surveys for compiling a
comprehensive inventory. Such a
view that impetus be provided for arachnid taxonomic research, particularly in
tropical and southern temperate regions before habitat modification and loss
takes a toll on many species, is corroborated by Harvey (2002).
The Asian whipscorpiondiversity has been a contentious premise for arachnologists;
firstly due to inadequate understanding of uropygidtaxonomy but mostly due to little agreement on species-specific morphological
clues across affiliates of the order Thelyphonida. With advancing imaging tools and
techniques, finer morphological details of great value in taxonomy have been
emerging, that can augment revisionary work (Harvey 2002).
Various researchers have attempted
to define the thelyphonid genera based on certain
morphological attributes such as ommatoids, pedipalps, and integument sculpture, inviting criticism
about over-emphasis of these morphological clues in uropygidtaxonomy and phylogeny (Haupt 2009). Notwithstanding the above criticism,
molecular methods are now central to determining phylogeny and nomenclature;
taxonomists have relied on morphological features that present species
specificity, and this approach is relatively inexpensive.
The arachnid diversity of the Indian
state of Goa is poorly documented except for the inventory prepared by Bastawade & Borkar (2008), bringing species affiliates of five orders from the state
on record. Further, much of the
focus in their inventory is on Araneae; continuing
the arachnid tradition of long neglect of other micro-diverse orders despite
their incredible characters. In the
present investigation, whip scorpion morphology has been
further augmented by using the scanning electron microscope to elucidate the
fine morphology that often escapes attention in conventional stereomicroscopy.
Methods
Diurnal surveys were carried out on
the basis of previously documented uropygid habitat
compatibility areas of the Sanguem and Dharbandora talukas of the state
of Goa during the monsoons of 2014–2017. The present active collection was made
from the riparian forest patch of Tamdi Village
outside the Bhagwan Mahaveerprotected area limits, about one kilometer from the famous Tamdi Surla Temple (see Image 1). The forest floor was
carefully scanned by slowly separating the leaf litter and upturning the stones
to locate these cryptozoic arachnids.
Once located, utmost care was
exercised not to disturb the species, as any slight mechanical stimulus
triggers a reflex spray of a strong vinegary, pungent smelling secretion. Also, once disturbed these arachnids bury
themselves in the crevices or the soft muddy substratum and get well
camouflaged amidst the decaying leaf litter, making it difficult to locate
them.
A few individuals of the species
were collected and transferred in a container with a bedding of wet leaf litter
and moderately sized stones for hiding. Animals were separated on the basis of their sexual dimorphism and
maintained individually in plastic terrariums at the School of Arachnology in
Biodiversity Research Cell of Carmel College for Women, Goa, under captive
conditions, ensuring the desired hygro-thermal
profile and natural photoperiod. Enclosure design and husbandry protocols were
followed as per McMoningle (2013). Captive enclosures were provided with
necessary substratum of leaf litter of approximately 2.5cm thickness and
coconut shell hideouts. Regular cleaning of leftover dead prey helped in
avoiding moulds. The captive individuals were supplied with freshly collected insect prey
once a week. No separate provision
for water was made in the containers, however, a piece of wet sponge was added
to the terrarium.
Gross and micro-morphological
studies and measurements necessitated killing the specimen by freezing and
preservation in 70% ethanol for further examinations. Routine stereomicroscopy (Model: Meiji
Techno, Japan) was used for gross morphology whereas micro-morphology was
elucidated by scanning electronic microscopy (SEM) at the National Centre for
Antarctic and Ocean Research (NCAOR), Bogda Goa
(Model: JSM-6360LV).
The present investigation is based
on the examination of collected specimen of both sexes (BRC-GOA/Arachno/maleUro-339/2016 & BRC-GOA/Arachno/femaleUro-351/2016)
and goes well beyond studying conventional gross morphological parameters, to
include micro-morphology. Stereomicroscopy
and SEM have been combined to elucidate fine structures of taxonomical
value. Also, detailed meristic data
has been generated for the whole body as well as individual ambulatory and
non-ambulatory appendages. This is
also the first attempt to understand an Indian uropygidwith SEM as a tool of investigation. This paper takes a look at functional morphology of pedipalp,
an important non-ambulatory structure. Also traditionally, pedipalps have been a
focus of investigation in revisionary taxonomy of thelyphonidspecies (Haupt & Song 1996).
Results
Habitat and habit
Most species of whip scorpions are
encountered in moist or seasonally moist forested habitats in tropical or
subtropical environments, burrowing in the deeper soil strata outside the wet
season. In Goa, their appearance in
their habitat coincides with the southwest monsoons, and by late July and early
August their sightings are frequent. The present sighting was recorded and specimens collected from the
riparian forest patch of Tamdi Village (15.43900N
& 74.25260E), in the vicinity of Bhagwan Mahaveer Wildlife protected area in DharbandoraTaluka of southern Goa. Across their geographic range the whip
scorpions find habitable space under logs, leaf litter, rotting wood, rocks,
and other natural dark places (Kern & Mitchell 2011).
In Goa,
the habitat of the specimens recorded and examined in this study, is typically
a riparian forest in and around the perennial and ephemeral forest streams; the
predominant terrestrial flora here being Gnetum ula, Wagatea spicata, Lagerstroemia dalbergioides,Pandanus odoratissimus, Garcinia indica, and Entada scandens. The general landscape here conforms
to moist deciduous (3B/C2)and semi evergreen (2A/C2)
forest types (Champion & Seth 1968) Some of the common tree species
encountered are Mangifera indica, Syzygium cumini, Schleichera oleosa, Pongamia pinnata, Tetrameles nudiflora, Bridelia retusa, Calophyllum inophyllum, Mallotus philippensis, Caryota urens, and Carissa carandas.
The
flora of the uropygid habitat assumes significance as these trees are the source of leaf litter
and decomposing dead wood that create the microhabitat of the whip
scorpion. Woodlands best indicate
the importance of habitat heterogeneity for various animals. Leaf litter,
branches and rotting logs at ground level in woodlands are known to influence
soil arthropod diversity and species richness, and particularly increase
species richness and changes in spider guild composition (Uetz1979).
Gross Morphology & Morphometry
In situ specimens of both sexes present shades of bluish-grey on the
dorsal tergal plates and dark reddish-brown on the
underside sternal surface (see Images 2A,B). Sexes were separated on the basis of
established differences in the shape of genital sterna, shape as well as size
of opisthosoma and pedipalpalcharacter (Gravely 1912, 1916; Weygoldt 1971, 1972,
1978; Yoshikura 1973).Thegenital sternum of the male was characteristically bulged and with hexagonal
profile, where as that of the female was tapering posteriorly presenting a
pentagonal margin. Similar sexual
dimorphism is also reported in Thelyphonus indicus, Stoliczka (Rajashekhar& Bali 1982).
In mature individuals the pleural
folds are prominently ridged and appear creamish-white.
The paired pedipalps in these specimen are robust
imposing articulate appendages with prey crushing interface, that operate
within a horizontal plane, aid in prey capture, courtship ritual and spermatophore insertion in the genital operculum of the female(Harvey 2003). Pedipalps are also implicated in fights with
same sex conspecifics, that are perceived as
territorial trespassers or mate competitors.
In this investigation, much emphasis
has been laid on understanding the functional morphology of the pedipalps and the associated structures. Comparative merisitcdata for both sexes has been tabulated (Tables 1, 2 & 3). The males are slender bodied with longerpedipalps, as compared to the stouter profile of the
females and short yet stocky pedipalps.
The modified first pair of
non-ambulatory legs are longer in the males. The opisthosomain both sexes terminate into a pygidium from which
arises a whip like flagellum (Images 3E,F). There is a single pair of laterally
placed ommatoids on the pygidium,
which appear as pale opaque spots. Usually the caudal flagellum is segmented,
folded and aligns flat over the body in resting individuals ,but at the slightest perception of disturbance, this caudal appendage is raised
and strategically manoeuvred to spray the defence secretion ejected from the base of the pygidium which is narrow, tubular and stub like.
Arising from the antero-lateral
aspect of the prosoma, pedipalpsshow discrete sexual dimorphism. In
males the pedipalps are leaner yet longer, with their
femur and tibia being almost double the length of its female counterparts.
In the genus Labochirus,the pedipalps show sexual dimorphism, in shape
and measurement. The pedipalps of the male are longer
than those of the female, which are short and stout (Images 3A,B). In males, the femur is clearly longer
and the terminal pincer comprising of the patella, tibia and tarsus is
characteristically angular (Image 4C). The ‘thumb like’ patellar apophysis of the
male is much enlarged and elaborated and is of much taxonomic value. In the
examined specimen of a male, patellar apophysialspines are irregular in placement, with only the apical spine being distinctly
longer (Image 4C). In the female pedipalp, the articulation between the tibia and patella
present a smooth convex profile of the terminal segments (Image 5C).
In the males, patellar apophysis is larger and points upwards, its terminal spine
intersecting the base of the tibial finger (Image
4C). The tibia is longer and flat
rather than with a curved dorsal profile as in females. The basitarsusis articulated with the tibia at almost a right angle and the distitarsus is bent inwards. The overall size, profile and articulation
of terminal segments, grant higher degree of manoeuvrabilityto the pedipalps in the males. Also, the somewhat worn out apex of
patellar apophysial spine suggestits abrasion with apposing surfaces (Image 4D). Comparatively the chelate construct of male pedipalps allowbetter apposition between the patellar apophysis and
tibia- tarsal complex for efficient grasping. That the pedipalpsare used by males in mate acquisition, spermatophoretransfer, besides defence purpose; further explains
their different design and worn out spines, as compared to that of the females.
Wherein the pedipalpalsurface in females is relatively smooth and shows sparse pits (Image 5),that of males has prominent tuberculation(Image 4). The distitarsalsegment in both sexes is devoid of serrations or teeth and has a relatively
smooth surface and margins. In the females, the proximal tarsal portion is characterised by conspicuous denticulate knobs bordering
the inner margin (Image 5D). These
‘tarsal teeth’ are arranged closely and form an opposing surface with the fixedtibial finger and a pincer with the patellar apophysis (Image 5C). The inner margin of the tibial finger has a
row of spinous stubs extending from the base of the
tibia to half the length of the tibial finger (Image
5C). Of these, the proximal ones
are slightly longer and pointed. They are widely spaced as compared to the
tarsal knobs.
Table 1. Meristic characters of Labochirus tauricornis,Pocock (male)
Parts of appendages |
Pedipalps (mm) |
1st leg (mm) |
2nd leg (mm) |
3rd leg (mm) |
4th leg (mm) |
Coxa |
5.3 |
3.6 |
4.1 |
4.1 |
4 |
Trochanter |
4.1 |
2 |
3 |
3.1 |
3.5 |
Femur |
11.1 |
9 |
5.7 |
7.1 |
7.9 |
Patella |
7.9 |
11.4 |
4.2 |
4 |
4 |
Tibia |
6.7 |
12.1 |
6.8 |
5.4 |
8.8 |
Pre-tarsus |
- |
- |
1.5 |
1.5 |
2.1 |
Tarsus |
4.6 |
7 |
3 |
3.5 |
4 |
Total length |
39.7 |
45.1 |
28.3 |
28.7 |
34.3 |
Table 2. Meristic characters of Labochirus tauricornis,Pocock (female)
Parts of Appendages |
Pedipalps (mm) |
1st leg (mm) |
2nd leg (mm) |
3rd leg (mm) |
4th leg (mm |
Coxa |
4.7 |
3.1 |
3.7 |
3.7 |
4.8 |
Trochanter |
4.8 |
2 |
3 |
3.3 |
4 |
Femur |
4.9 |
8 |
5.8 |
5.9 |
7.3 |
Patella |
4.5 |
10.4 |
4 |
3.5 |
4 |
Tibia |
3 |
9.6 |
5 |
5 |
7 |
Pre-tarsus |
- |
- |
1.4 |
1.7 |
2 |
Tarsus |
3 |
5.3 |
3 |
4.7 |
3.5 |
Total length |
24.9 |
38.4 |
25.9 |
27.8 |
32.6 |
Table 3. Comparative meristicsof male & female Labochirus tauricornis, Pocock from Tamdi, Goa
Cumulative dimensions (in mm) |
Male |
Female |
Prosoma total length |
12.8 |
11.6 |
Total breadth |
6.1 |
6.3 |
Opisthosoma total length |
16.2 |
16.7 |
Total breadth |
7.3 |
9 |
Flagellum length |
26 |
22 |
Patellar spine length |
2.6 |
3.1 |
Maxillary process length |
6 |
3.4 |
Discussion
Thus far, 103 species under 16
genera have been reported under the family Thelyphonidaefrom across the world (Harvey 2003). In India Bastawade (1988) reported Labochirus tauricornisunder the subfamily Hypoctoninae (Pocock)
and family Thelyphonidae (Lucas) from Kanara, Karnataka. Bastawade & Borkar(2008) reported this species for the first time in their preliminary arachnid
inventory of the Zoological Survey of India State Fauna Series for Goa, based
on specimens collected by Borkar; however, the
material examined were four females only and the approach was restricted to
gross morphology alone. This is the
first definitive record of occurrence of Labochirus tauricornis Pocock from
Goa, with collection and detailed examination of individuals of both sexes; unlike the earlier report (Bastawade& Borkar 2008). The location of the present collection
is a small hamlet called Tamdi in the Dharbandora Taluka of southern
Goa, characterised by riparian patches of moist
deciduous and semi evergreen flora. The present habitat is contiguous with the Bhagwan Mahaveer Wildlife Sanctuary of Goa. From the available distributional
records in India, it seems that L. tauricornishas a restricted presence in a small stretch of Western Ghats in Karnataka and
Goa.
Other species of Indian whip
scorpion to have been recorded from several Indian states are: Uropoctus assamensisfrom Arunachal Pradesh (Bastawade 2006), and Jalda Village in Bilaspur Chattisgarh in central India (Sharma & Chandra 2012).
The elucidation of pedipalpal micro-morphology in the present study addresses
the need to examine the particularly enlarged and elaborated patellar apophysis of the male of genus Labochirus,as being a valuable character for distinguishing species in uropygid systematics (Rowland & Cooke 1973). The data generated for morphometry and morphology of both sexes, besides the pedipalpal character of the examined specimen is in
conformity with the description for Labochirus tauricornis by Pocock1900. The SEM can be a particularly
valuable tool in taxonomic investigation of smaller arachnid orders like Uropygi.
Since the first report of whip
scorpion from Goa (Bastawade & Borkar 2008), no new species have been added to the uropygid list from this state. This could either suggest the presence
of a mono-specific uropygid population in this state,
or inadequate exploratory surveys dedicated to microdiversearachnid orders. Thelyphonus sepiaris is
the only uropygid that has been evaluated for its
conservation status in the country under the aegis of Conservation Assessment
and Management Plan workshop on selected soil invertebrates of southern India
(Daniel et al. 1998). Perhaps this
is because it has a wider distribution in India. The species is assessed as
Near Threatened (NT) nationally, largely due to habitat loss;and as Data Deficient (DD) Globally. Intriguingly, no such data is available for the remaining thelyphonids of India, including Labochirus tauricornis. But from the current status of known
whip scorpion habitats in Goa, their existence in the precincts and proximity
to protected areas of Bhagwan MahaveerWildlife Sanctuary keeps them inviolate.
References
Bastawade, D.B. (1988). A first report of an Arachnid order Uropygida (Whip Scorpion) from Maharashtra. Journal of the Bombay Natural History Society 85(3):
648–649.
Bastawade, D.B. ( 2006). Arachnida : Scorpionida, Uropygi, Schizomida and Oncopodid Opiliones (Chelicerata), pp.
449–465. In: Fauna of Arunachal Pradesh. State Fauna
Series, 13 (Part - 2). Zoological Survey of India, Kolkata, 518pp.
Bastawade, D.B. & M. Borkar (2008). ArachnidaOrders Scorpiones, Uropygi,Amblypygi, Araneae and Phalangida, pp. 211–242. In: Fauna of Goa. State Fauna Series 16. Zoological Survey of India, Kolkata, 549pp.
Champion, H.G. & S.K. Seth (1968). A Revised Survey of Forest Types of India. Govt. of India Press, New Delhi, 404pp.
Daniel, B.A., S. Molur & S. Walker (eds.) (1998). Report of the workshop “Conservation Assessment and Management
Plan for Selected Soil Invertebrates of Southern India” (BCCP-Endangered
species Project), Zoo Outreach OrganisationConservation Breeding Specialist Group, India, Coimbatore, India, 70pp.
Eisner, T., J. Meinwald, A. Monro & R. Ghent (1961). Defense mechanisms of arthropods - I. The composition and function of the spray of the whipscorpion, Mastigoproctus giganteus (Lucas) (Arachnida: Pedipalpida). Journal of Insect
Physiology 6: 272–298.
Gravely, F.H. (1912). Notes on the Pedipalpi in the collection
of the Indian Museum - III. Some new and imperfectly known species of Hypoctonus. Records of the
Indian Museum 8: 101–107.
Gravely, F.H. (1916). The evolution and distribution of the Indo-Australian Thelyphonidae, with notes on distinctive characters of
various species. Records of the Indian Museum 12:
59–86.
Harvey, M.S.
(2002). The neglected cousins: What do we know about
the smaller arachnid orders? Journal of Arachnology 30:
357–372.
Harvey, M.S.
(2003). Catalogue of the
Smaller Arachnid Oders of the World. CSIRO Publishing,
Victoria, Australia, 385pp.
Haupt, J. (2009). Proposal for the synonomy of some south
east asian whip scorpion genera (Arachnida,Uropyg, Thelyphonida). Revista Iberica Aracnologia 17:
13–20.
Haupt, J. & D. Song (1996). Revision of East Asian Whip Scorpions (Arachnida Uropygi Thelyphonida) - I. China and Japan. Arthropoda Selecta 5(3/4): 43–52.
Javed, S.M.M., K.T. Rao, F. Tampal & C. Srinivasulu(2009). First record of Thelyphonus sepiaris (Butler,
1873) (Uropygi: Thelyphonidae)
from Andhra Pradesh, India. Journal of Threatened Taxa 1(7):
395–397; http://doi.org/10.11609/JoTT.o2088.395-7
Kern, W.H. Jr. & R.E. Mitchell (2011). University of Florida: Featured creaturesentomology & Nematology. url:http://entomology.ifas.ufl.edu/creatures/misc/misc/giant whip scorpion. htm#life. Accessed3March 2013.
/<url: http://entomology.ifas.ufl.edu/creatures/misc/misc/giant_whip_scorpion.htm#life>.</url:
McMonigle, O. (2013). Forgotten Order of the Vinegaroons: Whip
Scorpion Biology, Husbandry and Natural History. Coachwhip Publications, Ohio, 131pp.
Pocock, R.I. (1900). Fauna of British India, Arachnida. Taylor and Francis,
London, 279pp.
Rajashekhar, K.P. & G. Bali (1982). Sexual dimorphism in a Whipscorpion, Thelyphonus indicus Stoliczka (Arachnida, Uropygj)Bulletin of British ArachnologicalSociety 5(7): 330–331.
Rowland, J.M. & J.A.L. Cooke (1973). Systematics of the Arachnid order Uropygida (Thelyphonida). The Journal of Arachnology 1: 55–71.
Sharma, R.M. & K. Chandra (2012). First report of Thelyphonus sepiaris (Butler, 1873) (Arachnida:Uropygi: Thelyphonidae)
from Chhattisgarh, Central India. Records of Zoological Survey of India 112(part-4):
129–130.
Uetz, G. (1979). The influence of variation in litter habitats
on spider communities. Oecologia 40: 29–42.
Weygoldt, P. (1971). Notes on the life history and reproductive
biology of the Giant Whipscorpion, Mastigoproctus giganteus (Uropygi, Thelyphonidae)
from Florida. Journal of Zoology London 164:
137–147.
Weygoldt, P. (1972). Spermatophore morphology and sperm
transfer in Uropygi (Mastigoproctus brasilianus C.L. Koch) and Amblypygi (Charinus brasilianus Weygoldt and Admetus pumilider tiereo C. L.
Koch). Zeitschrift fur Morphologie71: 23–51.
Weygoldt, P. (1978). Mating behaviour and spermatophore morphology in whipscorpions:Thelyphonellus amazonicus Butler and Typopeltis crucifer Pocock (Arachnida, Uropygi). Zeitschriftfur Zoomorphologie 89: 145–156.
Yoshikura, M. (1973). Whipscorpions of Japan. Kumamoto Journal of Science
(Biol.) 11(2): 81–93.