Gynacantha anandmati Sawant & Kambli, 2023

Sawant, Dattaprasad & Kambli, Amol, 2023, Gynacantha anandmati, a new species of dragonfly (Odonata: Anisoptera: Aeshnidae) from Maharashtra, India, Zootaxa 5239 (4), pp. 537-550 : 538-550

Gynacantha anandmati Sawant & Kambli

( Figs. 1–3 )

Holotype. J, Badlapur , Kalyan Taluka, Thane District, Maharashtra, India (19.183107 N, 73.244112 E; Alt: 15 m), 19.viii.2022, Amol Kambli leg.

Paratype. ♀, the location and collector same as for the J, date of collection 13.viii.2022.

Etymology. The species name is dedicated to late Mr. Sadanand Kambli and late Mrs. Indumati Kambli, beloved grandparents of the second author. The species epithet is the feminine genitive plural created from combining the two names ‘Anand’ and ‘Mati’.

Proposed English Name. Mumbai Duskhawker: specific name is given to honor the biodiversity of Mumbai and surrounding region.

Description of holotype ( Figs. 1–2 )

Head ( Fig. 1a–b ). Labrum yellow; labium olivaceous, laterally yellow; anteclypeus pale brown; postclypeus olivaceous, bordered with yellow; antefrons olivaceous to yellow, laterally blue; postfrons olivaceous with distinct ‘T-shaped mark’; eyes olivaceous green above, olivaceous below, blue at the junction, pale olivaceous yellow posteriorly; antennae dark brown, base orange; vertex green; ocelli creamy yellow; occipital triangle small, greenish yellow.

Thorax ( Fig. 1c–e ). Prothorax yellow to orange; posterior lobe pale yellow. Pterothorax olivaceous yellow on dorsum, orangish yellow on lateral, without any obvious markings; sutures well defined with orange hue; ventrally pale brown. Legs pale brown with black spines; coxae yellow; outer margin of tibia and tarsus yellow.

Wings ( Fig. 1c–d ). Hyaline, faintly tinted with pale yellow at base in median and subcostal areas; veins dark brown to black; pt brown, covering four to five cells; Ax: 17 (left)—15 (right) in FW, 10 (left)—12 (right) in HW; Px: 12 (left)—13 (right) in FW, 12 in HW; 3–4 rows of cells between IR2 and Rspl; 2–3 rows of cells between forking of IR2; anal triangle three-celled with central cell rectangular in both wings; anal loop with nine cells in the left wing and eight cells in the right wing.

Abdomen. Black with sharp blue-green markings on dorsal side, ventrally pale olivaceous; broad at base, significantly constricted at proximal S3, again expanding from distal S3 and till S10 having same breadth ( Fig. 1c, e ). S1 orange to brown, unmarked; S2 gradually tapering from base to apex, dark brown on dorsum, very fine yellow vertical stripe on midline, at the middle two slightly oblique broad yellow makings bordered by black, two blue markings at the apical end; auricles pale at the center, brown on periphery, ventrally olivaceous, fine black toothlike projections on posterior border ( Fig. 2a ); S3–4 dorsally black with horizontal yellow markings at the middle of the segment, fine pale green markings at the basal border, roughly triangular blue markings at the apical end, all markings interrupted by black at the middle, S3 laterally blue in proximal half ( Fig. 2a ); S5–7 dorsally black with horizontal green markings at the proximal one third of the segments, these green markings have bulge at medial, rest of the markings similar to S3–4 except broader apical blue triangles; S8 dorsally black, two inverted green triangles at the proximal one fourth of the segment, rest of the markings similar to previous segments except taller apical blue triangles; S9 black, two elongated blue triangular markings at the apical end; S10 dark brown with two obscure blue markings resembling somewhat inverted ‘M’ shape.

Accessory Genitalia ( Fig. 2b ). Anterior hamuli pearly white, narrow, apex sharply pointed; posterior hamuli short, pearly white; vesica spermalis brown, not dissected in the specimen; genital fossa bordered by small black tooth-like projections.

Caudal appendages ( Fig. 2c–f ). Cerci long and straight, 5.5 mm in length, horizontally flat, dark brown to black, apex darker; base pale yellowish merging with dark brown, of same width from base to apex; apex pointed without any distinct expansion, directed outwards, inner margin of apex rounded, outer margin nearly straight. Long hairs on inner margin of cerci, more in apical half portion; outer margin serrated. Paraproct nearly half of the length of cerci, 2.7 mm in length, creamy white, broad at base, gradually narrowing towards apex; apex dark brown to black and curved abruptly upwards ending in two sharp spines.

Measurements (in mm). Total length = 59, Abdomen + caudal appendages = 44, FW= 36, HW = 36.

Description of paratype ( Fig. 3 )

Head ( Fig. 3a ). Similar to male, more olivaceous with distinct ‘T-shaped’ mark on postfrons; eyes olivaceous above, brown below, blue markings like male are absent in the specimen.

Thorax ( Fig. 3b–c ). Prothorax and pterothorax similar to male. Legs more orange-brown.

Wings ( Fig. 3c–d ). Hyaline, similar to male; Ax: 17 in FW, 11 (left)—13 (right) in HW; Px: 13 in FW, 14 in HW; 4 rows of cells between IR2 and Rspl; anal loop with 9 cells in the left wing and 10 cells in the right wing.

Abdomen ( Fig. 3b–c ). Dorsally black, laterally orange to pale yellow, ventrally olivaceous; S1, S4–S7 similar to male; S2 more brown, two pale brown spots at apical end instead of blue spots in male, rest of the markings same; S3 less constricted, markings similar to male; S8 black with two small pale green triangles at the apical end; S9 black, two parallel yellow stripes slightly converging at the apical end; S10 brown, two pale spots at the basal end; basal plate and ovipositor pale yellow to brown, stylus brown.

Caudal appendages ( Fig. 3e–f ). Cerci long, black, damaged in collected specimen; paraproct very short, conical.

Measurements (in mm). Total length= 63, Abdomen + caudal appendages = 47, FW = 36, HW = 38.

Differential diagnosis. Gynacantha anandmati is most similar to G. albistyla and G. chaplini Khan, 2021 in overall appearance and anatomical structure. However, the following characters distinguish it from males of G. albistyla and G. chaplini : (a) straight cerci without any distinct apical expansion, apex directed outwards, inner margin of cerci apex is rounded and lateral margin is straight (in dorsal view), horizontally flat cerci in G. anandmati ( Fig. 2e–f ), whereas cerci somewhat twisted and apically round with a blunt spine directed inferio-laterally, a vertical ridge on distal 1/3 of the cerci (visible in lateral view) in G. albistyla ( Fig. 4f–i ) and cerci are apically expanded, both apical borders round with sharp spine pointed downwards in G. chaplini ( Fig. 6d ), (b) paraproct is abruptly turning anteriorly upwards at its apex in G. anandmati ( Fig. 2d, f ), whereas paraproct apex is facing posteriorly upwards in both G. albistyla ( Fig. 4g ) and G. chaplini (see Khan 2021, fig. 2E), not turning anteriorly, (c) anterior hamuli of G. anandmati don’t have any prominent lateral process ( Fig. 2b ), whereas anterior hamuli of both G. albistyla ( Fig. 4e ) and G. chaplini (see Khan 2021, fig. 2B) have prominent lateral process; (d) postfrons of G. anandmati have a distinct ‘T-shaped’ mark ( Figs. 1a–b , 7b ), whereas postfrons of G. albistyla unmarked (have a deep dark reddish brown border) ( Figs. 4d , 7a ) and that of G. chaplini have a trapezoid-shaped black marking ( Fig. 7d ), (e) dorsally green-blue markings on basal, central and apical end of abdominal segments in G. anandmati ( Fig. 1c, e ), and in G. chaplini markings only on apical end of abdominal segments, (f) obscure ‘M-shaped mark’ on S10 of G. anandmati ( Fig. 2c ), whereas a peculiar inverted ‘M-shaped mark’ on S 10 in G. albistyla ( Fig. 4f ), and unmarked S 10 in G. chaplini , (g) G. anandmati is overall a small species (total length = 59) as compared to G. chaplini (total length = 63.3). In summary, G. anandmati can be distinguished at a glance from G. albistyla and G. chaplini by peculiar shape of cerci and ‘T-shaped’ mark of postfrons. No other Indian Gynacantha spp. has such a straight, horizontally flat cerci. Another very similar species to G. anandmati is G. saltatrix (Martin, 1909) . However, it differs from G. anandmati by having shorter creamy white paraproct, brown abdomen with different green markings and bright green thorax. Moreover, G. albistyla has not been reported indubitably since its description. G. chaplini and G. saltatrix are yet to be found in Indian limits ( Kalkman et al. 2020).

Gynacantha anandmati male can be easily distinguished from the described males of remaining South Asian Gynacantha spp. by its peculiar long and straight cerci without any obvious apical expansion and creamy white paraproct of half the length of cerci ( Fig. 6 ). Gynacantha khasiaca has paraproct more than half the length of cerci ( Fig. 6f ) and distinct lateral thoracic stripes. Gynacantha andamanae Yeh & Veenakumari, 2000 , G. arnaudi Asahina, 1984 , G. bainbriggei Fraser, 1922 , G. bayadera Selys, 1891 ( Fig. 6c ), G. biharica Fraser, 1927 , G. dravida ( Fig. 6e ), G. incisura, Fraser, 1935 , G. millardi ( Fig. 6g ), G. odoneli Fraser, 1922 , G. pallampurica Lahiri, Sandhu & Walia, 2007 and G. subinterrupta Rambur, 1842 ( Fig. 6h ) have paraproct less than half the length of cerci. None of these species have vivid abdominal markings like G. anandmati .

Gynacantha anandmati female is very similar to G. albistyla female ( Figs. 3 , 5 ), but can be differentiated by ‘Tshaped’ mark on postfrons ( Fig. 3c ), which is absent in the latter ( Fig. 5c ). Two Gynacantha spp. namely, G. apicalis Fraser, 1922 and G. rammohani Mitra & Lahiri, 1975 are known only from female specimens. Gynacantha rammohani female lacks typical abdominal markings like G. anandmati . Gynacantha apicalis female has abdominal markings roughly similar to G. anandmati , but additionally has pigmented wing tips which are absent in the latter. Another species, G. rotundata was only known from its type specimen which is now unfortunately lost from Barcelona Museum (Museu de Ciències Naturals de Barcelona). Navás (1930) described the species based on a female collected from Borivali, Mumbai, India. According to him, G. rotundata female has rusty-greenish thorax, tawny to fulvous coloured abdomen with abdominal length of 42 mm which is considerably smaller and overall resemblance with G. hyalina Selys, 1882 ( Navás 1930) . There is no mention of vivid abdominal markings in Navás’s description like those found in G. anandmati . Therefore G. rotundata is a smaller species than G. anandmati which has G. hyalina or G. dravida like appearance. Furthermore, G. anandmati female can be distinguished from the described females of remaining South Asian Gynacantha spp. by typical abdominal markings, especially on S8–9.

Habitat and habits. The type locality is a riverbank of Ulhas River near the town of Badlapur, Thane District, Maharashtra ( Fig. 9a ). The riverbank is a mixed habitat of grasses and shrubs with an average altitude of 15m above sea level ( Fig. 9b ). Concrete buildings and roads of Badlapur surround the area. Tall grasses in monsoon serve as a good perching spot for many odonates such as Crocothemis servilia Drury, 1770 , Ictinogomphus rapax Rambur, 1842 , Microgomphus torquatus Selys, 1854 , Orthetrum pruinosum Burmeister, 1839 , Orthetrum sabina Drury, 1770 and Urothemis signata Rambur, 1842 . Many local fishermen use the area for parking their small boats and repairing fishing nets.

AK photographed a male G. anandmati ( Fig. 10a–c ) resting in grasses, probably a newly emerged specimen. However, he could not collect the male. After a few days he found one female and one male ( Fig. 10d ) resting in bushes at the same locality on 13 th August and 19 th August 2022 respectively. Probably due to the crepuscular nature of G. anandmati , he could not observe any other behavior of the species.

Distribution ( Fig. 11 ). Currently G. anandmati is known from Badlapur, Thane District, Maharashtra. Two unconfirmed observations have been made from Aarey Milk Colony, Mumbai Suburban District and Ovalekar Wadi, Thane District. Therefore, it is likely that the new species has its geographical distribution in Mumbai and Thane Districts. With the addition of G. anandmati , Western Ghats now harbors five Gynacantha spp. This shows the necessity of more Odonata surveys in the Western Ghats and peninsular India to fill the knowledge gaps in species distribution.

Note on identification of South Asian Gynacantha spp. Fraser (1936) developed identification keys for Indian Gynacantha spp. based on size, markings on postfrons (T-shaped mark or arrowhead mark), structure of caudal appendages and wing venation. Khan (2021) updated the keys and gave more importance to the markings of postfrons. Species like G. albistyla , G. andamanae , G. chaplini , G. odoneli , G. pallampurica and G. saltatrix were primarily identified by presence or absence of postfrons markings. However, we suggest that structure of caudal appendages, postfrons marking, abdominal pattern, wing venation, structure of secondary genitalia and variability in morphological appearance should be taken into account before confirming the species.

Here we update the key for males of South Asian Gynacantha spp. We exclude G. apicalis , G. rammohani and G. rotundata as these are known only from female specimens. Identification of all Gynacantha spp. except G. bainbriggei , G. biharica and G. odoneli is well established. Gynacantha bainbriggei and G. biharica should be thoroughly examined and compared with G. dravida and G. subinterrupta to determine their exact taxonomic status. Fraser (1936) suggested that specimens classified under G. millardi and G. odoneli may be conspecific, but without sufficient sampling, the comparison between the two would be inconclusive. For now, we use the keys provided by Fraser (1936) and Khan (2021) to accommodate these three species with some modifications.

Key to males of South Asian Gynacantha spp.

1. Paraproct> ½ the length of cerci ( Fig. 6f )........................................................ G. khasiaca

- Paraproct less ≤ ½ the length of cerci..................................................................... 2

2. Postfrons unmarked................................................................................... 3

- Postfrons marked..................................................................................... 6

3. Abdomen markedly constricted at S3, basal width of S3: smallest width of S3 <¾ ( Fig. 8a–c )........................ 4

- Abdomen less constricted at S3, basal width of S3: smallest width of S3> ¾ ( Fig. 8f ).............................. 5

4. Cerci straight, apical margins round ending in a blunt spine ( Fig. 6a ); thorax orange; abdomen with blue-green markings............................................................................................. G. albistyla

- Cerci almost straight, apex sharply pointed ( Fig. 6c ); thorax olivaceous green; abdomen brown to reddish dark brown................................................................................................ G. bayadera

5. Inner border of cerci bi-sinuous ( Fig. 6g ); larger species, HW> 40 mm .................................. G. millardi

- Inner border of cerci straight; smaller species, HW <40 mm ........................................... G. odoneli

6. Postfrons with ‘T-mark’................................................................................ 7

- Postfrons with other than ‘T-mark’...................................................................... 14

7. Paraproct ½ the length of cerci ( Fig. 6b )........................................................ G. anandmati

- Paraproct <½ the length of cerci......................................................................... 8

8. Paraproct> ⅓ but <½ the length of cerci.................................................................. 9

- Paraproct ≤ ⅓ the length of cerci........................................................................ 10

9. Paraproct 2/5 the length of cerci (See Fraser 1936, fig. 34b); abdomen pale lilaceous-brown to reddish-brown with less blue markings................................................................................ G. bainbriggei

- Paraproct> ⅓ but <½ the length of cerci; abdomen blackish-brown with vivid blue markings............... G. biharica

10. Cerci broad, paraproct dark brown...................................................................... 11

- Cerci narrow; paraproct yellow......................................................................... 12

11. Paraproct <⅓ the length of cerci ( Fig. 6h ); cerci less sinuous..................................... G. subinterrupta

- Paraproct ⅓ the length of cerci ( Fig. 6e ); inner border of cerci bi-sinuous................................ G. dravida

12. Cerci with a deep incision near its base on the inner border (See Fraser 1936, fig. 32b)..................... G. incisura

- Cerci without any incision............................................................................. 13

13. Cerci apex turned outwards................................................................ G. pallampurica

- Cerci apex pointing downwards................................................................. G. arnaudi

14. Postfrons with ‘arrow’ mark (see Yeh and Veenakumari, 2000)..................................... G. andamanae

- Postfrons with a trapezium-shaped mark ( Fig. 7d ).................................................. G. chaplini

Figures

FIGURE 1. Gynacantha anandmati Holotype male: (a) anterior view of head; (b) dorsal view of head; (c) dorsal habitus; (d) forewing and hindwing; (e) lateral habitus.

FIGURE 2. Gynacantha anandmati Holotype male: (a) dorsal view of S3; (b) ventral view of hamuli; (c) dorsal view of caudal appendages; (d) lateral view of caudal appendages; (e) close up of dorsal view of cerci tip; (f) close up of lateral view of cerci tip.

FIGURE 3. Gynacantha anandmati Paratype female: (a) dorsal view of head; (b) lateral habitus; (c) dorsal habitus; (d) forewing and hindwing; (e) dorsal view of abdominal end segments; (f) lateral view of abdominal end segments.

FIGURE 4. Gynacantha albistyla Lectotype male [NHMUK 013324098]: (a) dorsal habitus; (b) lateral habitus; (c) forewing and hindwing; (d) dorsal view of head; (e) ventral view of hamuli; (f) dorsal view of caudal appendages; (g) lateral view of caudal appendages; (h) close up of dorsal view of cerci tip; (i) close up of lateral view of cerci tip. Photos: Dr. Ben Price and Dan Hall (Natural History Museum, London, UK).

FIGURE 5. Gynacantha albistyla Paratype female [NHMUK 013324113]: (a) dorsal habitus; (b) lateral habitus; (c) dorsal view of head; (d) forewing and hindwing; (e) dorsal view of abdominal end segments; (f) lateral view of abdominal end segments. Photos: Dr. Ben Price (Natural History Museum, London, UK).

FIGURE 6. Caudal appendages of male Gynacantha spp. in dorsal views. (a) G. albistyla; (b) G. anandmati; (c) G. bayadera; (d) G. chaplini; (e) G. dravida; (f) G. khasiaca; (g) G. millardi; (h) G. subinterrupta (not to scale).

FIGURE 7. Postfrons of Gynacantha spp. in dorsal views. (a) G. albistyla; (b) G. anandmati; (c) G. bayadera; (d) G. chaplini; (e) G. dravida; (f) G. khasiaca; (g) G. millardi; (h) G. subinterrupta (not to scale).

FIGURE 8. S3 of male Gynacantha spp. in dorsal views. (a) G. albistyla (Photo: Dr. Ben Price); (b) G. anandmati; (c) G. bainbriggei (Photo: Dr. Ben Price); (d) G. bayadera (Photo: Dr. Ben Price); (e) G. dravida; (f) G. millardi (Photo: Hemant Ogale) (not to scale).

FIGURE 9. Habitat of Gynacantha anandmati (a) Site of collection Ulhas river bank, Badlapur and (b) Ulhas river bank, Badlapur.

FIGURE 10. Gynacantha anandmati in situ. (a–c) male, 6.viii.2022, Badlapur, Maharashtra, India; (d) male [collected specimen], 19.viii.2022, Badlapur, Maharashtra, India.

FIGURE 11. Distribution map depicting distribution records of ‘orange-bodied’ Gynacantha spp. namely, G. albistyla, G. anandmati and G. chaplini.