Austruca Bott, 1973

Lin, Yu-Jia, Qurban, Mohammad A., Shen, Kang Ning & Chao, Ning Labbish, 2019, Fig. 4 in Fig. 4 in Responses of Phyllostomid Bats to Traditional Agriculture in Neotropical Montane Forests of Southern Mexico., Zoological Studies 58 (12), pp. 1-21 : 3-14

Genus Austruca Bott, 1973

Austruca variegata ( Heller, 1862) ( Figs. 1a–c , 2 , 3a–b , 4a–d , 5a–d , 6a–c, f , 7a, b, e , 8a–d , 9 ) urn:lsid:zoobank.org:act:3E16AD8E-C907-4E0A-B14C-3026181664DC

Gelasimus variegatus Heller, 1862: 521 (type locality: Madras, India); Crane 1975: 326.

Gelasimus perplexus – Heller 1865: 38, pl. 5(4) (Madras, India; Ceylon); A. Milne-Edwards 1873: 274 ( India). (not Gelasimus perplexa H. Milne Edwards, 1837 )

Gelasimus triangularis – Henderson 1893: 388 (Madras and Ennore, India); Alcock 1900: 356 (Bay of Bengal). (not Gelasimus triangularis A. Milne-Edwards, 1873 )

Uca triangularis – Nobili 1903: 20 ( Pondicherry, India); Altevogt 1957: 3, 5, figs. 11, 23, 27 (southeastern India); Feest 1969: 159, figs. 6, 7, 9, 11, 13, 14, 16, 18, 19, 20, 22, 24, 26, 28, 29 ( Pondicherry, India); Dev Roy and Bhadra 2005: 509, pl. 3(8) (Andhra Pradesh, India); Dev Roy and Nandi 2007: 181, 188 (Tamil Nadu, India); Dev Roy and Bhadra 2008: 155 (list); Rath and Dev Roy 2008: 77, pl. 5(5) (Krishna, India); Dev Roy and Bhadra 2011: 207 (Tamil Nadu, India); Rath and Dev Roy 2011: 60, pl. 4(2) (Orissa, India); Kappalli et al. 2012: 967 (Muzhapilangad estuary, North Kerala, India); Satheeshkumar 2012: 315 ( Pondicherry, India); Fredrick and Ravichandran 2013: 442 (Tamil Nadu, India); Hossain 2015: 202 (part; 1 unnumbered fig. = Metaplax sp. ) ( Bangladesh); Sen and Homechaudhuri 2015: 82 (Sundarban, India); Supriya et al. 2017: 647 (Muzhapilangad estuary, North Kerala, India). (not Gelasimus triangularis A. Milne-Edwards, 1873 )

Uca (Celuca) triangularis bengali Crane 1975: 286 , figs. 24I, J, 32N, O, 59A, 68C, 101 (part); Krishnan 1992: 471, pl. 1; Bairagi 1995: 274 (West Bengal, India). (not Uca (Celuca) triangularis bengali Crane 1975 )

Uca bengali – Rosenberg 2001: 860, 866 (part). (not Uca (Celuca) triangularis bengali Crane 1975 )

Uca (Paraleptuca) bengali – Beinlich and von Hagen 2006: 26 (list), fig. 5i (part); Ng et al., 2008: 241 (list, part). (not Uca (Celuca) triangularis bengali Crane 1975 )

Uca triangularius bengali [sic] – Ravichandran and Kannupandi 2007: 334 (Pichavaram, India). (not Uca (Celuca) triangularis bengali Crane 1975 )

Uca triangularis bengali – Soundarapandian et al. 2008: 115 (Pichavaram, India); Chatterjee and Das 2014: 113, fig. 5 (West Bengal, India). (not Uca (Celuca) triangularis bengali Crane 1975 )

Uca inversa – Satheeshkumar and Khan 2011: 315; Satheeshkumar 2012: 315 ( Pondicherry, India). (not Gelasimus inversa Hoffmann, 1874 )

? Uca inversa – Dev Roy and Nandi 2012: 218 (list) (Andaman and Nicobar, India).

Uca lactea – Talapatra et al. 2014: 908, fig. 4 (Odhissa, India). (not Ocypode (Gelasimus) lactea De Haan, 1835 )

Austruca bengali – Shih et al. 2016: 153 (list, part); Trivedi et al. 2018: 54. (not Uca (Celuca) triangularis bengali Crane 1975 )

? Uca (Austruca) bengali – Akash and Chowdhury 2017: 201, fig. 2 (?) ( Bangladesh).

Austruca triangularis – Trivedi et al. 2018: 54 (part). (not Gelasimus triangularis A. Milne-Edwards, 1873 )

Cranuca inversa – Trivedi et al. 2018: 54. (not Gelasimus inversa Hoffmann, 1874 )

Material examined: Lectotype, ò ( CW 16.7 mm,

PL 24.7 mm) ( NHMW 25656; original Novara label, #74 = AN. 1866.II.74.; labelled as “ Gelasimus perplexus M. Edw. ”), Madras, India, coll. Johann Zelebor.

Others: 1 ò (17.2 mm) ( NHMW 12974; no original label), Madras, India, coll. J. Zelebor. 5 òò (11.6–16.6 mm) ( ZRC 2001.0853), Vellar River estuary, Parangipettai (= Porto Novo), Tamil Nadu, India, coll. N. N. Ng, 23 Mar. 2001; 1 ò (18.6 mm) ( ZRC 2018.1375), 9 òò (9.8–17.3 mm) (NCHUZOOL 14362), 12 òò (8.8–17.8 mm) (NCHUZOOL 14363), Vellar River estuary, Parangipettai (= Porto Novo), Tamil Nadu, India, coll. M. Prema and S. Ravichandran, 6 Aug. 2017; 5 òò (12.0– 17.1 mm), 1 ñ (13.7 mm) (NCHUZOOL 14366), 1 ñ (16.6 mm) (NCHUZOOL 14365), 6 òò (10.2–16.9 mm), 7 ññ (9.7–15.4 mm) (NCHUZOOL 14367), Vellar River estuary, Parangipettai (= Porto Novo), Tamil Nadu, India, coll. M. Prema and S. Ravichandran, July–Aug. 2017; 2 òò (16.1–17.2 mm), 1 ñ (14.5 mm) ( ZRC 2003.0463), mangroves, Pitchavaram, Tamil Nodu, India, coll. N. Sivasothi and Chongsing, 12 Mar. 2000; 10 òò (14.5– 18.4 mm) ( ZRC 2017.0917), Danthadhpatrobar, Cantai, Midnapure, West Bengal, India, coll. Z. Jaafar, 25 Nov. 2004; 2 òò (18.5–18.9 mm) ( ZRC 2017.0915), Kolkata aquarium trade, Mar. 2010.

Comparative material: Austruca bengali : Thailand: 1 ò (9.7 mm) (NCHUZOOL 13646), 1 ñ (9.9 mm), 5 juv. (NCHUZOOL 14359), Bang Rin mangroves, Ranong, coll. H.- T. Shih, 27 May 2012; 2 òò (9.1–10.1 mm), 7 juv. (NCHUZOOL 14360), 3 òò (10.4–11.4 mm), 3 juv. (NCHUZOOL 14361), Tha Thiap Ruea Bang Rong, Phuket, coll. H.- T. Shih, 30 May 2012. Malaysia: 1 ò (8.0 mm) (NCHUZOOL 13575), 18òò (10.4–14.5 mm), 8 ññ (9.8–12.0 mm), 12 juv. (NCHUZOOL 14345), estuary of Sungai Sementa Besar, Kampung Perepat Kapar, Selangor, coll. H.- T. Shih, 10 Feb. 2009. Austruca triangularis : New Caledonia: 1 ò (10.4 mm), 2 ññ (8.2–8.6 mm) ( QM W29057), Dumbea Point, coll. P. Davie, 8 Feb. 1992; 2 òò (9.0– 11.4 mm) ( QM W29056), 1 ñ (12.4 mm) ( QM W29058), Pam, New Caledonia, coll. P. Davie, 10 Oct. 1992. Australia: 3 òò (9.8–12.1 mm), 1 ñ (10.2 mm) ( QM W19251), Thomatis Creek, Queensland, coll. P. Davie et al., 30 Oct. 1993. Indonesia: 2 òò (13.1–15.3 mm) (NCHUZOOL 14347), Badung, Kuta, Bali, coll. H.- T. Shih, 16 July 2014; 2 òò (11.3–11.4 mm) ( QM W24251), Pantuan, Kalimantan, coll. E. Dutrieux, unknown date. Malaysia: 1ñ (8.3 mm) (NCHUZOOL 14346), Labuan, coll. H.- T. Shih, 24 July 2010. Philippines: 1 ò (10.6 mm) (NCHUZOOL 14354), 4 òò (10.9–12.5 mm), 1 ñ (12.2 mm) (NCHUZOOL 14355), Zamboanga, Mindanao, coll. C. K. R. Ong, 10 June 2006; 6 òò (12.4–17.1 mm) (NCHUZOOL 14357), Pago R., Mindanao, coll. H.-C. Liu, 13 July 2007; 5 òò (12.4–14.2 mm), 1 ñ (11.9 mm) (NCHUZOOL 13574), 1 ò (14.8 mm) (NCHUZOOL 14358), Cebu, coll. L. Liao, 2 Sep. 2003; 1 ò (11.5 mm), 2 ññ (10.3–10.4 mm) (NCHUZOOL 14349), 1 ñ (14.6 mm) (NCHUZOOL 14350), 1 ò (11.2 mm) (NCHUZOOL 14351), 1 ò (10.6 mm), 2 ññ (10.4–12.4 mm) (NCHUZOOL 14352), Matutinao R. Badian, Cebu, coll. H.- T. Shih, 6 Sep. 2003; 3 òò (8.1–10.1 mm), 2 juv. (NCHUZOOL 14356), Puerto Galera, coll. P.-C. Tsai and K. Wong, 5 June 2009. Taiwan: 2 òò (9.1–12.5 mm), 2 ññ (8.8–12.3 mm) (NCHUZOOL 14710), Baoli River estuary, Pingtung, coll. H.- T. Shih, 14 Sep. 1997; 1 ò (13.2 mm), 1 ñ (5.2 mm) (NCHUZOOL 14712), Baoli River estuary, Pingtung, 20 July 2011; 3 òò (11.4–13.0 mm) (NCHUZOOL 14745), Yanshuei River estuary, Tainan, coll. students, 4 Aug. 2009; 1 ñ (8.7 mm) (NCHUZOOL 14711), Yanshuei River estuary, Tainan, coll. students, 18 Oct. 2011; 2 òò (10.2–11.5 mm), 1 ñ (11.9 mm) (NCHUZOOL 14709), Lanyang River estuary, Yilan, 25 July 2004. Cranuca inversa : 1 ò (19.9 mm) (NCHUZOOL 14904), Al Darb, Red Sea, Arabia, coll. Anand. Jeya Kumar, 25 Apr. 2017.

Diagnosis: Male. Front moderately broad. Carapace ( Figs. 1a , 2a , 3a, b ) with orbits slightly oblique; anterolateral angles (= external orbital angles) broadly triangular, directed anteriorly; anterolateral margins short; dorsolateral margin long, definite, converging. Floor of orbits with some weak tubercles medially ( Fig. 4a–d ). Major cheliped ( Fig. 1a–c , with posterodorsal margin of merus with a single row of small, sharp tubercles or serrations at convex crest, anterodorsal margin not arched, with serrated row ( Fig. 1c ); palm broad, with minute tubercles on outer surface, inner surface with proximal predactylar ridge strong and oblique row of granules proximoventrally; dactylus broad, with 1 short shallow groove proximal and subdorsally; pollex broad. Merus of minor cheliped with weak longitudinal row of tubercles above posteroventral

(a)

(b)

(c)

(d)

margin, curves abruptly upward at distal end, short distance before end of segment. Gape of minor cheliped with serrations on distal part. Meri of second, third ambulatory legs moderately wide, dorsal margin of first, fourth meri almost straight. G1 with flange short, slightly curved, distal edge slightly expanded, almost truncate; thumb tumid, broad as adjacent shaft, extending well beyond flange base ( Fig. 6a–c, f ). Urocardiac ossicles of gastric mill moderately complex, with 4 or 5 pairs of transverse ridges of median tooth, separated by gaps reached deeply near central ridge, on posterior tooth plate; 4 pairs of cusps on stem region ( Fig. 7a, b, e ).

Female. Anterolateral ( Fig. 8a ) margins long, almost straight, turning at angle into dorsolateral margins. Meri of ambulatory legs moderately wide ( Fig. 8a ). Vulva (female gonopore) ( Fig. 8d ) in shallow sternal depression, but not tuberculate.

Coloration in life ( Fig. 9 ): Carapace interlaced with black and pale blue (or yellowish white) transverse bands, some individuals with wider black bands on posterior portion. Eyestalks and major cheliped yellow. Legs pale blue (or yellowish white) with black speckles.

Ecological notes: According to Krishnan (1992), this species in Madras “exhibits a patchy distribution, restricted to the high saline areas where the substratum is clay-mud”. Austruca annulipes (H. Milne Edwards, 1837) is the only sympatric species in southeastern India ( Altevogt 1957; Feest 1969; Krishnan 1992; Dev Roy and Bhadra 2005; Fredrick and Ravichandran 2013). In the northern Bay of Bengal, it was reported to be sympatric with Austruca annulipes , Tubuca rosea (Tweedie, 1937) , T. paradussumieri ( Bott, 1973) , Gelasimus hesperiae ( Crane, 1975) (see Talapatra et al. 2014; Sen and Homechaudhuri 2015).

Distribution: From the Bay of Bengal (including Sri Lanka) to the Laccadive Sea (see the synonym list). According to Krishnan (1992), the distribution may be extended to the whole eastern side of the Indian subcontinent (from Ganges Delta to Karaikal). Kappalli et al. (2012) and Supriya et al. (2017) studied the population (as Uca triangularis ) from southwestern India in the Laccadive Sea.

Remarks: As discussed earlier, Heller (1862: 521) briefly diagnosed Gelasimus variegatus from Madras (present day Chennai) in India but did not indicate how many specimens he had. Later, even after he synonymized it with “ Gelasimus perplexus ” (not Gelasimus perplexa H. Milne Edwards, 1837 , s. str.), he did not indicate how many specimens he had from Madras. Crane (1975: 326) searched for the types in vain, commenting that “I have been unable to locate any material referred to this species. In particular the type-specimen was not found in the museum in Vienna when I asked for it in 1963. According to the short type description in Latin, this species is close to annulipes but includes a denticulate crest on the major merus. Almost certainly variegatus and inversa are synonymous. However, inversa has not been recorded from eastern India, while variegatus was described from Madras. The specimens were collected on the roundthe-world expedition of the “Novara”. According to oral reports, mistakes on the labels have been encountered in other material resulting from that trip, and it is not unlikely that the type-material of variegatus was collected farther west.” A fresh search for “ Gelasimus variegatus ” in the Naturhistorisches Museum Wien failed to find specimens under this name, but there

(g) (h)

are two extant lots labelled as “ Gelasimus perplexus ” among Heller’s material from Madras (P. C. Dworschak, personal communication). They were all collected by Johann Zelebor who was a staff member during the Novara Expedition. One of these lots ( NHMW 25656 and 12980) still carries the original Novara label which states “#74 = AN. 1866.II.74” and contains 100 males and 2 females. The other lot ( NHMW 12974), with seven males, does not have the original label but is also part of the expedition material. Although these specimens do not carry the name “ Gelasimus variegatus ”, it is quite clear that they are part of the type series and are thus syntypes. It would appear that Heller (1865) decided that his “ Gelasimus variegatus Heller, 1862 ” was the same as “ Gelasimus perplexus ” and removed all the labels with the former name in the lots, retaining only the accepted name at that time. That was why Crane (1975) failed to find the type specimens of Gelasimus variegatus . Based on the labels in these two lots, the specimens were actually examined by the late Hui-Lian Chen as well as Diana Jones who identified them as “ Uca triangularis (H. Milne Edwards, 1852) ” and “ Uca bengali Crane, 1975 ”, respectively, although none of this information has been published to our knowledge. While we have not managed to examine all the specimens in both lots, Peter Dworschak was kind enough to photograph for us the best specimens in these lots and allow us to acertain their identities. To stabilize the taxonomy of the species and to leave no doubt about its identity, we here select a male specimen with CW 16.7 mm ( NHMW 25656) as the lectotype of Gelasimus variegatus Heller, 1862 ( Fig. 1a, b ).

Austruca variegata closely resembles A. bengali and A. triangularis , but can be distinguished easily by the morphology of carapace, major and minor chelipeds, G1, gastric mill structure and coloration (see Table 2 for details). In A. variegata , the orbit is only slightly oblique in position ( Fig. 3a, b ) (distinctly oblique in other species; Fig. 3c, d ); the anterolateral angles are broadly triangular and directed anteriorly ( Fig. 3a, b ) (acute and directed laterally in other species, but that on A. bengali is very acute; Fig. 3c, d ); the anterolateral margins is short ( Fig. 3a, b ) (absent in A. bengali and very short in A. triangularis ; Fig. 3c, d ); the dorsolateral margin is converging ( Fig. 3a, b ) (strongly converging in other species; Fig. 3c, d ); the tubercles on the orbital floor are weak and only present medially ( Fig. 4a–d ) (none in A. bengali ( Fig. 4e–f ); with strong tubercles in females and males (at least on minor side) in A. triangularis ( Fig. 4g –h )); the chelae of major cheliped is broad ( Fig. 5a, c ) (slender in other species; Fig. 5e, g ); the groove on major dactylus is one short shallow groove proximally and subdorsally ( Fig. 5a, c ) (one shallow groove proximally and subdorsally and another long shallow groove just above gape in other species; Fig. 5e, g ); the proximal predactylar ridge is long and very strong ( Fig. 5b, d ) (long and strong in A. bengali ( Fig. 5f ); short and the tubercles fewer or, rarely, absent in A. triangularis ( Fig. 5h )); the longitudinal row of tubercles above the posteroventral margin on the minor merus is weak (strong in other species; see Crane 1975: fig. 51A); the G1 flange is short and the thumb is stout and broad as the adjacent shaft ( Fig. 6a–c, f ) (flange short and thumb slender in A. bengali ( Fig. 6d, g ); flange long and the thumb is less stout but also broad as adjacent shaft in A. triangularis ( Fig. 6e, h )); the female vulva is a shallow depression and not tuberculate ( Fig. 8d ) (with a blunt tubercle in A. bengali ( Fig. 8e ); with a definite apex directed internally in A. triangularis ( Fig. 8f )); and the gastric mill is moderately complex with 4 or 5 pairs of ridges of median tooth and 4 pairs of cusps on stem region ( Fig. 7a, b, e ) (simple, 3 pairs and 1 pairs in A. bengali ( Fig. 7c, f ); complex, 7 or 8 pairs and 5 or 6 pairs in A. triangularis ( Fig. 7d, g )).

The color and patterns of the three species ( Figs. 9–11 ) are different enough to distinguish them in the field. The color of major cheliped is yellow with no speckles in A. variegata ; yellowish orange with no speckles in A. bengali ; but it is pale brown, covered with brown speckles in A. triangularis . The color of ambulatory legs is also diagnostic, being mottled (pale background with black speckles) in A. variegata , neither mottled nor banded in A. bengali and dark brown with paler bands in A. triangularis .

Among the three species of this complex, Austruca variegata was published in 1862, and predates Austruca triangularis (A. Milne-Edwards, 1873) and A. bengali ( Crane, 1975) ; so it is perhaps better to name this the “ Austruca variegata complex”.

It is pertinent to note that in discussing Gelasimus tetragonon (Herbst, 1790) , H. Milne Edwards (1837: 52, footnote) listed the name “ Gelasima variegata, Latr. Coll. du Mus. (fem.)” under its synonymy. This name is clearly a nomen nudum, and on the basis of the synonymy, not the same taxon as what is here regarded as Austruca variegata ( Heller, 1862) .

Figures

Fig. 1. Male Austruca variegata (Heller, 1862) (a–d) and Cranuca inversa (Hoffmann, 1874) (e). (a) habitus; (b, c) major cheliped; (d, e) merus of right major cheliped. (a, b) lectotype, CW 17.2 mm (PL 24.7 mm, NHMW 25656; Madras, India), originally identified as A. perplexa. (c) “Gelasimus perplexus” in Heller (1865: pl. 5(4)). (d) male (CW 18.6 mm, ZRC 2018.1375; Tamil Nadu, India). (e) CW 19.9 mm (NCHUZOOL 14904; Al Darb, Arabia). Scale bars = 5.0 mm.

Fig. 2. Austruca variegata (Heller, 1862). a–d, male (CW 18.6 mm, CL 10.7 mm, PL 26.6 mm, ZRC 2018.1375). (a) habitus; (b) major cheliped; (c) pleon; (d) minor cheliped. Scale bar = 5.0 mm.

Fig. 3. Carapaces of male Austruca variegata (Heller, 1862) (a, b), A. bengali (Crane, 1975) (c) and A. triangularis (A. Milne-Edwards, 1873) (d). (a) CW 16.6 mm (ZRC 2001.0853; left-handed; Tamil Nadu, India); (b) CW 14.5 mm (ZRC 2017.0917; left-handed; West Bengal, India); (c) CW 14.5 mm (NCHUZOOL 14345; right-handed; Selangor, Malaysia); (d) CW 14.8 mm (NCHUZOOL 13574; lefthanded; Cebu, Philippines).

Fig. 4. Floors of orbit of male Austruca variegata (Heller, 1862) (a–d), A. bengali (Crane, 1975) (e, f) and A. triangularis (A. Milne-Edwards, 1873) (g, h). (a, b) CW 18.6 mm (ZRC 2018.1375; right-handed; Tamil Nadu, India); (c, d) CW 14.5 mm (ZRC 2017.0917; left-handed; West Bengal, India); (e, f) CW 14.5 mm (NCHUZOOL 14345; right-handed; Selangor, Malaysia); (g, h) CW 14.8 mm (NCHUZOOL 13574; left-handed; Cebu, Philippines). Scale bars = 5.0 mm.

Fig. 5. Outer and inner sides of major palm of Austruca variegata (Heller, 1862) (a–d), A. bengali (Crane, 1975) (e, f) and A. triangularis (A. Milne- Edwards, 1873) (g, h). (a, b) CW 16.6 mm (ZRC 2001.0853; left-handed; Tamil Nadu, India); (c, d) CW 14.5 mm (ZRC 2017.0917; left-handed; West Bengal, India); (e, f) CW 14.5 mm (NCHUZOOL 14345; right-handed; Selangor, Malaysia); (g, h) CW 14.8 mm (NCHUZOOL 13574; lefthanded; Cebu, Philippines).

Fig. 6. Right G1s of Austruca variegata (Heller, 1862) (a, b, c, f), A. bengali (Crane, 1975) (d, g) and A. triangularis (A. Milne-Edwards, 1873) (e, h). (a, f–h) lateral view of distal part; (b) mesial view of distal part; (c–e) lateral view. (a, b) CW 16.6 mm (ZRC 2001.0853; Tamil Nadu, India); (c, f) CW CW 14.5 mm (ZRC 2017.0917; West Bengal, India); (d, g) 14.5 mm (NCHUZOOL 14345; Selangor, Malaysia); (e, h) 14.8 mm (NCHUZOOL 13574; Cebu, Philippines). Scale bars: a, b, f–h = 0.5 mm, c–e = 1.0 mm.

Fig. 7. Urocardiac ossicles of Austruca variegata (Heller, 1862) (a, b, e), A. bengali (Crane, 1975) (c, f) and A. triangularis (A. Milne-Edwards, 1873) (d, g). (a) male (CW 16.1 mm, ZRC 2003.0463; Tamil Nadu, India); (b, e) female (CW 14.5 mm, ZRC 2003.0463; Tamil Nadu, India); (c) male (CW 13.1 mm, QM W27320; Phuket, Thailand); (d) male (CW 14.8 mm, NCHUZOOL 13574; Cebu, Philippines); (f) male (CW 12.5 mm, QM W27320; Phuket, Thailand); (g) female (CW 14.6 mm, NCHUZOOL 14350; Cebu, Philippines). Scale bars = 0.5 mm.

Fig. 8. Female Austruca variegata (Heller, 1862) (a–d), A. bengali (Crane, 1975) (e) and A. triangularis (A. Milne-Edwards, 1873) (f). (a) habitus; (b) floor of right orbit; (c) right minor cheliped; (d–f) right vulva (gonopore). (a–d) CW 16.6 mm (NCHUZOOL 14365; Tamil Nadu, India); (e) CW 12.4 mm (QM W27320; Phuket, Thailand); (f) CW 14.6 mm (NCHUZOOL 14350; Cebu, Philippines). Scale bars: b, c = 5.0 mm, d–f = 0.5 mm

Fig. 9. The live coloration of Austruca variegata (Heller, 1862) (a–h). (a, b) dorsal view of male; (c, d) frontal view of male; (e) dorsal view of female; (f) two males fighting; (g) two males moving to low intertidal zone for feeding; (h) a male A. variegata (left) and a male A. annulipes (H. Milne Edwards, 1837) (right) sympatric in one locality. Specimens not captured. Photos taken from Vellar River estuary, Porto Novo, Tamil Nadu, India.