The Striated Parachute
Spider Poecilotheria striata Pocock, 1895 (Araneae: Theraphosidae): a note on taxonomy, distribution and
conservation status
Manju Siliwal1, Neha Gupta 2 & Sanjay Molur 3
1,3 Wildlife Information Liaison
Development Society, 96, Kumudham Nagar, Vilankuruchi Road, Coimbatore, Tamil Nadu 641035, India
2 Guru GobindSingh Indraprastha University, Sector 16-C, Dwarka, New Delhi, India
3 Zoo Outreach Organization,
96, Kumudham Nagar, VilankuruchiRoad, Coimbatore, Tamil Nadu 641035, India
1 manjusiliwal@gmail.com (corresponding author), 2 neha_11taurian@rediffmail.com,3 herpinvert@gmail.com
Abstract: The known distribution
range of Poecilotheria striata Pocock, 1895 in India is from Mysuruin the north to Thiruvananthapuram in the south. During the recent surveys in northern
Karnataka, P. striata was recorded from six
locations in Dandeli and nearby areas in the Uttara Kannada District. With the new records from Uttara Kannada, the distribution range of this species
extends to the northern part of the Western Ghats by ca. 400km from Mysuru. Additional records on distribution of P. striata are also provided from various surveys carried out in the last 10
years. Based on these new records,
the IUCN Red List status of P. striata is recommended to be reassessed as Near Threatened. Additional information on
the morphology and natural history of P. striatais provided in the paper.
Keywords: Araneae, India, IUCN Red List
Assessment, mygalomorph, range extension, taxonomy, Theraphosidae.
Abbreviations: ALE - anterior lateral
eye; AME - anterior median eye; MOQ - median ocular quadrate; PLE - posterior
lateral eye; PME - posterior median eye; PLS - posterior lateral spinnerets;
PMS - posterior median spinnerets; STC - Superior or paired tarsal claws; WILD
- Wildlife Information Liaison Development Society; d - dorsal, fe - femur; mt - metatarsus; p - prolateral, pa - patella, r - retrolateral,
ta - tarsus, ti - tibia, v - ventral.
doi: http://dx.doi.org/10.11609/JoTT.o2956.4630-40 | ZooBank:urn:lsid:zoobank.org:pub:BF21D16F-87CE-49A7-9038-75700321B18E
Editor: Ansie Dippenaar-Schoeman,
University of Pretoria, Queenswood,
South Africa. Date of
publication: 26 August 2013 (online & print)
Manuscript details: Ms #
o2956 | Received 27 November 2011 | Final received 28 May 2013 | Finally
accepted 08 August 2013
Citation: Siliwal,
M., N. Gupta & S. Molur (2013). The Striated
Parachute Spider Poecilotheria striata Pocock, 1895 (Araneae: Theraphosidae): a note
on taxonomy, distribution and conservation status. Journal of Threatened
Taxa 5(12): 4630–4640; http://dx.doi.org/10.11609/JoTT.o2956.4630-40
Copyright: © Siliwalet al. 2013. Creative Commons Attribution 3.0 Unported License. JoTTallows unrestricted use of this article in any medium, reproduction and
distribution by providing adequate credit to the authors and the source of
publication.
Funding: Initial surveys were funded by
the Rufford Small Grants to Sanjay Molur, and recent surveys were funded by DEFRA / FFI
Flagship Species Fund (No. 06/16/02 FLAG) and CEPF (Critical Ecosystem
Partnership Fund) -ATREE (Ashoka Trust For Research
In Ecology And The Environment) Western Ghats Small Grants Program to Manju Siliwal.
Competing Interest: The
authors declare no competing interests. Funding sources had no role in study
design, data collection, results interpretation and manuscript writing.
Acknowledgements: Authors
are grateful to the following personnel and institutions: PCCF, Karnataka
Forest Department for giving permission and logistic help during the surveys;
Mr. Sunil Kumar, Deputy Conservator of Forest, DandeliWS, and Mr. R. Gokul, Conservator of Forests, Karwar Division for the logistic support and help during
the surveys; Mr. Ramesh and Mr. Suraj Chauhan for assisting in field during the surveys; Dr. Gautam Talukdar, Wildlife
Institute of India for helping in map preparation and Dr. Bilal Habib, Wildlife Institute of India for technical help. NG
wishes to deeply thank Dr. Sanjay Keshari Das,
Assistant Professor, Guru Gobind Singh Indraprastha University, Delhi for all the encouragement
and support he provided as a supervisor for Master’s dissertation during which
this spider was found.
Author
Details and Contribution: Manju Siliwal has been working on spiders since 1997.
She has specialized on taxonomy of primitive spiders (mygalomorphsincluding tarantulas) and has described many new species from India. Her main
interests are taxonomy, ecology and conservation of Indian spiders. Her
contribution to this paper is in carrying out surveys, identifying the species
and preparing the manuscript. Neha Guptais MSc in biodiversity and conservation and interested in ecology and
conservation of Indian spiders. For her MSc dissertation, she worked on the
ecology of trapdoor spiders of the family Idiopidaein Uttara Kannada, Karnataka. Her contribution to
this paper is in assisting in examination of specimens and finalizing
illustrations and text. Sanjay Molur initiated the research on tarantulas in India
in 2000 to understand their distribution, threats and conservation status. His fields of interest include the study
and conservation of lesser-known fauna, flora and
fungi. He is the Red List focal
point for primates and invertebrates. His contribution to this paper is through
initial surveys, overseeing the tarantula project, and help with preparing and
editing the manuscript.
This article forms part of a special
series on the Western Ghats of India, disseminating the results of work
supported by the Critical Ecosystem Partnership Fund (CEPF), a joint initiative
of l’Agence Française de Développement, Conservation International, the European
Commission, the Global Environment Facility, the Government of Japan, the
MacArthur Foundation and the World Bank. A fundamental goal of CEPF is to
ensure civil society is engaged in biodiversity conservation. Implementation of
the CEPF investment program in the Western Ghats is led and coordinated by the Ashoka Trust for Research in Ecology and the Environment
(ATREE).
For figures, images, tables -- click here
INTRODUCTION
The old world genus Poecilotheria Simon, 1885 of the tarantula family Theraphosidae is represented by 15 species in the world,
out of which eight are endemic to India and seven to Sri Lanka (Gabriel 2010; Platnick 2013). It is the only genus of the Theraphosidae in
India that is exclusively arboreal in habit and is found largely in the dry
deciduous and evergreen forests or wooded areas in peninsular India and Sri
Lanka. This genus is very popular
in pet trade. Fourteen species of theraphosid spiders were assessed for their threat status
and included in the IUCN Red List of Threatened Species in 2008; eight species
were reported to be threatened with extinction due to restricted distribution,
habitat loss, fragmentation and pet trade (Molur et
al. 2008). This included all nine
known species of Poecilotheria including, P.nallamanlaensis Rao et
al., 2006, which was recently synonymised with P. formosa Pocock,
1899.
Poecilotheria striatawas first described from Pinang, Malaysia, based on a specimen deposited in the
British Museum of Natural History (=Natural History Museum), London. However, the type locality was suspect
as there had been no previous reports of occurrence of Poecilotheriafrom Malaysia. Four years later Pocock (1899) received another specimen of P. striata from southern India and confirmed that the type
locality to be southern India rather than Pinang. Later, Pocock (1900) reported this species from Mysuru in Karnataka and Thriuvananthapuramin Travancore (= Kerala). Gravely
(1915) reported P. striata from Pamben, Rameshwaram Island, Tamil
Nadu, but Smith (2004) found it to be a new species and described the Rameshwaram populations as P. hanumavilasumica.
Kirk (1996) synonymised Poecilotheria vittata Pocock, 1895
under P. striata, and Moluret al. (2004) stated that the report of P. regalisfrom Vazhachal Forests in Thrissur,
Kerala by Cheeran & Nagaraj(1997) was actually P. striata due to the
absence of the epigynal yellow band.
During the recent theraphosid surveys in UttaraKannada District, Karnataka, MS and NG collected the specimens of Poecilotheria from various locations in Dandeli and nearby areas. On examining the ventral leg pattern,
chelicerae and maxillary lyrastructure, female spermathecae and male palp
structure they were identified as P. striata. Despite P. striatabeing common in the pet trade, there is very little information on the habitat,
biology and population status in the wild. In this Communication we redescribe the
species adding to the few morphological characters described by Pocock (1895), and discuss its distribution, provide
natural history notes and reassess the Red List status of this species.
MethodS
All specimens are deposited
at the Wildlife Information Liaison Development (WILD) Society Museum,
Coimbatore, Tamil Nadu, India. Measurements of body parts except for
the eyes are taken with a MitutoyoTM vernier caliper. Eye measurements are done with a calibrated ocular micrometer. All measurements are in millimeters. Spermathecae are dissected and cleared in concentrated
lactic acid in 1000C water bath for 15–20 minutes. Total length excludes chelicerae. All
illustrations are prepared with the help of a camera lucidaattached to a MOTICTM and LabomedTMCSM2 stereomicroscopes by NG and MS. The taxonomic description style is after Siliwal et al. (2009).
Taxonomy
Poecilotheria striata Pocock, 1895
(Images 1–6; Figs.
1–21; Tables 1–2)
Poecilotheria striata Pocock,
1895: 172; 1899: 89; 1900: 191.
Poecilotheria vittata Pocock,
1895: 172, (in part) synonymised by Kirk 1996: 22.
Type specimen: Designated
female as the type specimen, deposited at Natural History Museum, London, not
examined.
Material examined
WILD-10-ARA-632, one female,
7.ii.2010, 15.161870N & 74.637040E, 517m, Kulgi, Dandeli WS, Uttara Kannada, Karnataka, India, coll. M. Siliwal, N. Gupta and Ramesh; WILD-10-ARA-647, one
juvenile, 9.iii.2010, same data as of 632; WILD-10-ARA-1062, one male,
4.v.2010, 15.167310N & 74.634020E, 509m, Kulgi, Dandeli WS, Uttara Kannada, Karnataka, India, coll. Suraj Chauhan and Ramesh; WILD-10-ARA-571, one male
7.i.2010, 15.132030N & 74.365280E, 452m, Janta Colony, near Dandeli, Uttara Kannada, Karnataka, coll. Saroj Behera; WILD-10-ARA-553, WILD-10-ARA-560,
WILD-10-ARA-561, three juveniles same locality; WILD-10-ARA-624, one juvenile,
2.ii.2010, 15.180790N & 74.552750E, 577m, Ulvi Road, Potoli, Dandeli WS, Uttara Kannada,
Karnataka, coll. M. Siliwal, N. Gupta and Ramesh;
WILD-10-ARA-390, one juvenile, 15.iii.2010, 15.158220N &
74.626640E, 468m, Naghzari, Kulgi, Dandeli WS, Uttara Kannada, Karnataka, coll. M. Siliwal,
N. Gupta, Ramesh and S. Chauhan; WILD-10-ARA-732, one
juvenile, 20.iii.2010, 15.216110N & 74.435040E, 587m,Diggi, Uttara Kannada,
Karnataka, M. Siliwal, N. Gupta, Ramesh and S. Chauhan.
Diagnosis
This species closely
resembles Poecilotheria regalisin colour and patterns on legs but differs as
follows: absence of a band ventrally on the abdomen; yellow band on the leg
femora with more orange tint; longer legs; carapace much shorter than patella
and ti I (Pocock 1900);
maxillary lyra present on prolateralface; in female maxillary lyra two black
tubercle/teeth-like spines and 3–4 curved rows of pedal setae; in male
maxillary lyra a single black tubercle/tooth-like
spine with 3–4 curved rows of pedal setae; legs I-II ventrally with
bright yellow and black pattern, femur yellow with broader black diagonal band
about three quarters distally, patella yellow proximally with black and
irregular band across the middle (Smith & Kirk unpub.). Spermathecae,
simple fused seminal receptacles, broader at the base, gradually narrowing down
to half the width towards apex; male palp, a large pyriformbulb with stout embolus that has a lipped apical keel which divides into three
curved keels that spiral over the embolus.
Description of female
(WILD-10-ARA-632)
Total
length 49.27. Carapace 23.19
long, 20.34 wide, chelicerae 13.73 long. Abdomen 26.08 long, 20.15 wide. Spinnerets:
PMS, 2.45 long, 0.71 wide, 0.65 apart; PLS, 3.16 basal, 2.27 middle, 3.92
apical, mid-widths 1.26, 1.14, 1.16 respectively, 9.35 total length.
Colour in life
(Image 1):Carapace and chelicerae black at base, covered with dense mat of short wavy
golden hairs, more dense towards margins and concentrated along interstitial
ridges radiating from fovea, long curved light brown hairs at periphery; mid
dorsal black patch surrounding patch of pallid/grey hair around fovea and
caput; chelicerae with two black vertical hairless bands running its
length. Legs hairy, covered with
mat of greyish and black small hair intermixed with long brown hair with pallid
tips; dorsal greyish with black annulations and white markings; ventral, black
and yellow bands on fe, pa, tiand mt of legs I-II, palp with white and black bands
on fe, pa, ti and mt of legs III-IV. Abdomen dorsally, black chevron mark running along length of abdomen,
ventrally black.
Carapace (Fig. 1): Length to width ratio 1.14. Bristles: 6 between AME, 10 long, 12
short between PME; 26 long, 19 short on clypeus edge. Mat of
fine hair on anterior and posterior ocular area, fine golden hair at base of
PLE. Fovea
deep, slightly procurved. Caput not much higher
than cephalic and thoracic region.
Eyes (Fig. 2): Group occupies 4.25 of head-width 13.36;ratio of group width to length 2.59. AME clearly larger than
rest, PME clearly smaller than rest. Eyes on low
ocular tubercle. Eye
diameter: ALE, 0.94; AME, 1.01; PLE, 0.75; PME, 0.32. Distance between eyes: AME-AME, 0.67;
PME-PLE, adjacent; AME-ALE, 0.55; PME-PME, 2.01. Ocular
quadrate, 1.64 long, 4.25 wide. MOQ: length, 1.53;
anterior width, 2.04, posterior width, 2.85. Clypeus absent.
Maxillae (Image 2, Figs 3–4): 7.60 anterior length, 8.99
posterior length, 4.91 wide. Posterior edge near heel
slightly concave, anterior lobe distinct, posterior ventral edge gently rounded
for whole length. Cuspules: ca. 280 sparsely arranged
in triangular shape in anterior corner. On prolateralface, two bands of thick brush of greyish black hairs above and below maxillary
suture. Maxillary lyra consists of two thick tooth-like black tubercles with
many paddle shape setae in 3–4 rows on prolateralface, all paddle setae reddish-brown except for base and swollen tips black,
two small thick setae present above paddle setae (but absent on other maxilla,
this could be a natural variation); two broad bands of grey long hair. Retrolateralface reddish-brown, glabrous in center with thin short spines distal and retroventral edge. Serrula, broad
curved band behind anterior lobe running down posteriorly.
Labium (Fig. 4): 2.32 long, 3.19 wide; ca. 80 cuspulesin band for one-fourth of length anteriorly; cuspulesca. similar in size to maxillary. Basal groove shallow, distinct. Labiosternal groove convex. One pair of large
sternal sigilla present in labiosternalgroove.
Chelicerae (Figs. 4–5): Intercheliceral spines absent. Covered with
mat of grey, pallid hair intermixed with long black hair on dorsal and lateral
sides. Chelicera lyra, with short thorn spines
arranged in oval shape on proximal lower retrolateralface. Prolateral face glabrous, reddish-brown; 16 promarginalteeth, 55 basomesal teeth in 2–4 rows.
Sternum (Fig. 4): 10.48 long, 9.05 wide. Almost round, high in centre, sloping
gradually, covered with long and short brown hair. Posterior tip short
and not very sharp and not separating coxae IV. Posterior edge clearly
visible. Prostrate hair mat
strong, dense, of pallid hairs intermixed with long black hair, few with pallid
tips. Two to
three rows of long black hair present on margins. Pedicel
pallid, not clearly visible.
Sigilla (Fig. 4): 3 pairs, posterior pair
oval, 0.61 diameter, ca. 3.33 apart, 0.88 from margin; middle pair oval, 0.39
diameter, 5.86 apart, 0.43 from margin; anterior pair very small, round,
marginal.
Legs: Formula 4123. Anterior legs slightly thicker
than posterior legs but overall all of similar thickness. Basifemoralthorns absent on all. All metatarsi longer than tarsi. Mt I 2.4 times longer than
ta, mt IV 2.3 times longer than ta, others about 2.0
times longer than tarsi. Spines absent on all legs.
Trichobothria:Tarsi: I, 44 clavate, ca. 100 long and short filiform; II, 47 clavate, ca. 100
long and short filiform; III, 44 clavate,
ca. 70 long and short filiform; IV, 45 clavate, ca. 80 long and short filiform;
palp, 42 clavate,
ca. 65 long and short filiform. Clavate on
I-IV in distal half in two bands; filiforms in two
bands for length, each band with 4–5 rows of trichobothria.Short epitrichobothrial hair field
on all tarsi as wide as trichobothrial hair and
uniform height for length. Metatarsi: only filiformpresent in curved band of 2–3 rows, I, 26; II, 23; III, 28; IV, 46.
Leg coxae (Fig. 6–8): Coxal bases dorsally easily seen
from above (Image 1). I longest,
about 1.18 times length of II; IV basally with anterior corner indistinct, edge
curves dorsally, rounded at interface. Coxae ventrally with blackish-brown mat of
small hairs at base intermixed with short and long black hair, prolateral faces of I-IV consists of hairs, all coxa sloping backward. Retrolateral setation:
I-IV with median narrow light brush of pallid hair; all coxae retrolaterally lack ventral ledge.
Leg pilosity: All legs covered with long
hairs giving them more robust appearance. Fe of all legs ventrally with pallid and black
brush-like long hair. All
legs covered with mat of grey short hair. Fe I-II with long brush of long hairs on retroventralside, fe III-IV with very few
long hairs retroventral sides. I: fe, p=12, d=22, r=v=30; pa, p=30, d=20, r=40, v=24; ti, p=70, d=50, r=v=60; mt, p=40,
d=50, r=30, v=5; ta, p=r=15, d=50. II: fe,
p=15, d=r=25, v=30; pa, p=v=r=20, d=15; ti, p=50,
d=40, r=v=60; mt, p=r=40, d=30, v=7. III: fe, p=r=30, d=20, v=40; pa,
p=r=20, d=15, v=25; ti, p=30, d=25, r=35, v=60; mt, p=d= r=30, v=20; ta, p=4, d=30, r=6. IV: fe, p=70, d=40, v=20; pa, p=40,
d=23, r=15, v=30; ti, p=50, d=r=40, v=70; mt, p=v=r=40, d=30; ta, p=15, d=40, r=8.
Scopula: Entire on all tarsi, I-IV
not divided but scopulae pattern shows midventral narrow gap-like division but no hair visible
dividing scopulae in preserved specimen; mt I-II- on ¾ distal, not divided, few long hair in centre and ventrolateral; mt III- on distal 2/3rd basally divided by few
hair; mt IV- on ½ distal divided by 4-5 rows
of hair.
Tarsal weakness: Not prominent because of strong mat of hairs on tarsi.
Claws: Paired claws on leg I-IV with unequal bifid tooth. Palp with single bare claw.
Abdomen (Image 1, Fig. 1): Cuticle not exposed dorsally and ventrally;
dorsally covered with thick mat of black and grey hair, fine layer of black
with pallid tips long hair, many pallid; ventrally and ventrolateraluniformly black, thick mat of fine black hair, intermixed uniformly with long
black with pallid tips.
Spinnerets: Two pairs, digitiform, yellowish
covered with mat of grey and brown hairs intermixed with many long black hair
with pallid tips.
Spermatheca (Fig. 9): Simple, fused seminal receptacles, broader at base, gradually
narrowing down to half width towards apex.
Description of male
(WILD-10-ARA-1062)
Total
length 36.93. Carapace
18.95 long, 16.5 wide, chelicerae 11.11 long. Abdomen 17.98
long, 10.91 wide. Spinnerets: PMS, 1.90 long, 0.54 wide 0.48 apart; PLS,
2.82 basal, 2.02 middle, 3.88 apical, mid-width 1.02, 0.84, 0.74 respectively,
8.74 total length.
Colour in life (Image 3): Markings on carapace, legs
and abdomen faded due to aging. Carapace, blackish covered with curved golden and purplish hairs more
concentrated towards margins and striae, on either
sides of ocular area, faint black patch; on periphery long black hair with
pallid tips in 2–3 rows; between eyes strong mat of greyish and golden
small hair intermixed with long and short bristles, more dense between
PME. Legs,
chelicerae, margins of carapace and ventral and lateral sides of abdomen
pale/coffee brown. Legs
hairy, covered with mat of greyish and black small hairs intermixed with long
brown hair with pallid tips; patterns on legs dorsally faded, ventral, black
and yellow bands on fe, pa, tiand mt of legs I-II, palp and white and black bands
on fe, pa, ti and mt of legs III-IV. Abdomen covered with thick mat of grey hair intermixed with long black
hairs with pallid tips, dorsally with faded black chevron mark running whole
length of abdomen, ventrally covered with mat of black hair intermixed with
long black hair.
Carapace (Image 3, Fig. 10): Length to width ratio 1.15; reddish-brown,
darker towards periphery; covered with strong mat of short black hairs, more
dense towards margins and concentrated along interstitial ridges radiating from
fovea, long curved light brown hairs at periphery. Bristles: 17 long, 14 short anteriormedially; 4 long, 8 short between AME; 6 long, 12
short between PME; 8 long, 12 short on clypeus edge. Mat of
fine hair on anterior and posterior ocular area, fine golden hair at base of
PLE. No setae. Fovea straight. Caput is not much higher than cephalic
and thoracic region.
Eyes (Fig. 11): Group occupies 3.21 of head-width; ratio
of group width to length 2.26. AME clearly larger than rest,
PME clearly smaller than rest. Eyes on ocular low
tubercle. Eye diameter: ALE, 0.62; AME, 0.74; PLE, 0.55; PME, 0.24.
Distance between eyes: AME-AME, 0.64; PME-PLE, adjacent; AME-ALE, 0.31;
PME-PME, 1.66. Ocular quadrate, 1.42 long, 3.21 wide. MOQ: length, 1.42; anterior width 1.96, posterior width 2.16.Clypeus absent.
Maxillae (Image 4, Figs 12–13): 6.04 anterior length, 7.24
posterior length, 3.96 wide. Posterior edge near heel slightly
concave, anterior lobe distinct, posterior verntraledge gently rounded for length. Cuspules: ca. 210 sparsely arranged in anterior corner in triangle region. Maxillary lyraconsists of one tooth like setae, on its proximal side paddle setae in
3–4 curved rows forming rectangular band covering ½ area on
maxillae; two bands of thick brush of grey hairs above and below maxillary
suture. Prolateral face, scattered short and long hair present, band of
setae present above maxillary suture. Retrolateral face reddish-brown, glabrous in center, with mat of short grey
hair on distal and retroventral edge. Serrula, broad
curved band behind anterior lobe running down towards posteriorly.
Labium (Fig. 13): 2.34 long, 3.11 wide; ca. 46 cuspulesin band for one-fourths of length anteriorly; cuspulesca. similar in size to maxillary. Basal groove shallow, distinct. Labiosternal groove convex. One pair of large
sternal sigilla present in labiosternalgroove.
Chelicerae (Fig. 13): Intercheliceral spines absent, covered with mat of grey hair intermixed with long
black hair with pallid tips on dorsal and lateral sides. Chelicerae lyra same as female, consists of short thorn seatae on proximal lower side on retrolateralface in an oval shape. Prolateral, retrolateral faces glabrous,
reddish-brown; 16 promarginal teeth, 29 basomesal teeth.
Sternum (Fig. 13): 8.11
long, 6.32 wide. Almost oval, sloping towards margins, uniformly covered with
short black hair intermixed with long black hair and bristles. Posterior angle short
and not very sharp and not separating coxae IV. Posterior edge clearly
seen. Prostrate hair mat
strong, black hairs intermixed with black bristles. Thick row of long black bristles present
on margins. Pedicel
pallid, not clearly visible.
Sigilla (Fig.
13): three
pairs, posterior, oval, 1.15 diameter, ca. 2.32 apart, 1.09 from margin;
middle, oval, 0.56 diameter, 4.48 apart, 0.63 from margin; anterior, very
small, round, marginal.
Legs (Figs 14–16): Formula 4123. All legs of similar thickness. Basifemoral thorns absent on all. All metatarsi
longer than tarsi. Mt I 2.8 times longer than ta, mtIV 2.6 times longer than ta, others about 2.4 times longer than tarsi.
Trichobothria:Tarsi: I,16 clavate, ca. 80–100
long and short filiform; II, 32 clavate,
ca. 80 long and short filiform; III, 31 clavate, ca. 70 long and short filiform;
IV, 12 clavate, ca. 80 long and short filiform; palp, 12 clavate, ca. 30-40 long and short filiform. Clavate on I-IV in distal ½ in two bands; filiformsfor length in two bands, each band of 3–4 rows. Short epitrichobothrial hair field on all tarsi as wide as trichobothrial hair and uniform height for length.Metatarsi: only filiform present in curved band of
2-3 rows, I, 30; II, 24; III, 40; IV, 45.
Leg coxae: Coxal bases dorsally easily seen
from above (Image 1). I longest, about 1.2 times length of II;IV edge curves dorsally, rounded at interface. Coxaeventrally with short black hair intermixed with long black hair, prolateral faces of I-IV consists of hairs. I-IV ventrally
covered with black mat of small hairs at base of coxaintermixed with long and short black hair, all coxasloping backward. Retrolateral setation:
I-IV with median narrow light brush of pallid/grey hair; all retrolaterally lack ventral ledge.
Leg pilosity: All legs covered with hairs
saucing it to appear thicker. Fe I with band of black long
hair in center. Fe I-II ventrally have pallid
brush like long hair retroventral side, fe III-IV with few long hairs on ventral side. All legs
covered with mat of greyish short hair. I: fe, p=50, d=20,
r=40; pa, p=30, d=3, r=20, v=3; ti, p=40, d=15, r=60,
v=80; mt, p=10, d=35, r=, v=5; ta, p=r=40-50, d=5.
II: fe, p=25, d=10, r=40;
pa, p=15, r=5, d=15, v=10; ti, p=15, d=50, r=20,
v=25; mt, p=7, d=20, r=30; ta, d=25, p=r=6. III: fe, p=30, d=15, r=20, v=10; pa,
p=5, d=7, r=5, v=7; ti, p=15, d=r=25, v=20; mt, p=10, d=20, r=10; ta, p=3, d=17. IV: fe, p=25, d=35, r=15, v=10; pa,
p=15, d=8, r=10, v=15; ti, p=30, d=35, r=25, v=25; mt, p=20, d=35, r=15, v=18; ta, p=8, d=18, r=6.
Scopula: Entire on all tarsi,
intermixed with hair, not divided; mt I-II- on
¾ distal, few long hair in centre ventrolateral; mt III- on distal 2/3rd basally divided by few hair; mt IV- on ½ distal divided by 2-3 rows of hair.
Metatarsi scopulae intermixed with long black hair
and bristles at base.
Tarsal weakness: Not prominent because of strong mat of hairs on tarsi.
Claws: Paired claws on leg I-IV with an unequal bifid tooth.
Abdomen (Image 3, Fig. 10): Dorsally with black-haired chevron running from
anterior to posterior end, rest covered with thick mat of gray and brown hair;
cuticle not exposed dorsally and ventrally; uniformly covered with dense black
hairs with pallid tips, more concentrated compared to female (reddish in life);
ventrally and ventrolaterally blackish-brown
intermixed uniformly with long pallid and golden hair.
Spinnerets (Fig. 17): Two pairs, digitiform, covered with mat
of grey and brown hair and many long pallid hair.
Palp (Figs. 18–21): Large pyriform bulb, stout embolus with
lipped apical keel dividing into three curved keels that spiral over embolus.
Remarks
In February 2010, a large
specimen of P. striata was collected
(WILD-10-ARA-571), which resembled the female of this species due to its large
abdomen. It was kept alive in
captivity and after three weeks moulted into a male.
Interestingly, when the spider died, the maxilla lyra was found to resemble that of a female (Image
5), consisting of two teeth like spines (only one tooth in males). It is not clear whether it is a case of
sex transformation or simply a variation in maxillary lyra setae, coinciding with a large abdomen subadult male. Though there have been reports of sex change in theraphosidsdue to the bacteria Wolbachia (Rowley et al.
2004), we hypothesise captivity related sex change
due to stress as this was observed in three more similar individuals observed
in captivity in WILD in 2000–2001 (Sanjay Molurpers. obs.). However, more
observations in captivity and microbial and molecular studies are needed before
deriving any conclusions.
Distribution
Poecilotheria striata closely resembles P. regalis but it can be distinguished from P. regalis morphologically by the absence of a yellow band
on the epigynal area (Pocock1900). There is an overlap of
distribution ranges of both the species, and in the past, these species have
been recorded to co-exist in the same localities, habitat and retreats in the
Western Ghats (Molur et al. 2004). Poecilotheria striata was known prior to this study from only
two confirmed locations, i.e., from Mysuru, Karnataka
and Thiruvananthapuram, Kerala based on museum records. Despite these spiders being popular in
pet trade, their distribution records have been very poorly known. During the past ten years, there have
been opportunistic sightings of P. striata in
different parts of southern India, most of them falling within the known
distribution range (between Mysuru and
Thiruvananthapuram) except for the recent records of P. striata from six locations in Dandeliand nearby areas in Uttara Kannada District extending
the range by about 400km north (Image 6). It is likely that P. striata has as
wider distribution range than that of P. regalisbut more surveys are required to confirm this.
The distribution information
for P. striata from literature and field
surveys is provided in Table 1 (Pocock 1895; Pocock 1899; Pocock 1900; Cheeran & Nagaraj 1997; Siliwal et al. 2008). The majority of the sightings were in teak forests and very few from
evergreen forests, which may be because of better visibility in open or less
dense forests. Further, new records
show that the species has a wider distribution range than previously reported
from a few pockets in the southern Western Ghats. It is mainly due to lack of surveys in
these areas that the species has not been reported previously.
Conservation status
Poecilotheria striata was listed as Vulnerable [(B1ab(ii, iii)+2ab(ii, iii)] according to the IUCN Red List,
2008 (Siliwal et al. 2008) due to restricted
distribution and various threats like pet trade, habitat loss and
fragmentation. The present record
of this species from different locations in UttaraKannada reveals that this species has a much wider distribution range than
formerly thought and the area of occupancy and extent of occurrence have
increased. Therefore, the
threatened status of P. striata needs to be
downgraded to Near Threatened from Vulnerable.
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