Tubuca alcocki Shih, Chan & Ng, 2018

Shih, Hsi-Te, Prema, Mani, Kumar, Austin Anand Jeya, Saher, Noor Us, Ravichandran, Samuthirapandian, Odhano, Sahir & Paulay, Gustav, 2022, Fig. 9 in Fig. 1 in Fig. 20. A-E in Establishment of A New Bornean Genus of Gecarcinucidae (Crustacea: Brachyura), with Descriptions of Five New Species., Zoological Studies 61 (65), pp. 1-18 : 11-12

Tubuca alcocki Shih, Chan & Ng, 2018 ( Fig. 3G, H )

Gelasimus dussumieri H. Milne Edwards, 1852: 148 , pl. 4(12) [part]; Alcock 1900: 361; Chhapgar 1957: 510, pl. 14a–f; Chandy 1973: 402.

Gelasimus acutus – Alcock 1900: 360.

Gelasimus urvillei – Alcock 1900: 362.

Uca (Deltuca) [coarctata] urvillei – Crane 1975: 35, 58–61, figs. 8B, 9E, pl. 9C, D [part].

Uca (Deltuca) urvillei – Hogarth 1986: 222; Price et al. 1987: 456, 464; Krishnan 1992: 471.

Uca (Deltuca) dussumieri – Krishnan 1992: 471.

Uca urvillei – Tirmizi and Ghani 1996: 103, fig. 39; Saher 2008: 21, fig. 2.2, pl. 2.1; Odhano et al. 2015: 170, figs. 1, 2.

Uca (Tubuca) urvillei – Beinlich and von Hagen 2006: 10, 14, 25, fig. 7f, k; Ng et al. 2008: 242.

Uca dussumieri – Trivedi et al. 2012: 17, 20, fig. 3e; Beleem et al. 2014: 422.

Uca (Tubuca) acuta – Trivedi et al. 2015: 27.

Uca (Tubuca) dussumieri – Trivedi et al. 2015: 27.

Tubuca urvillei – Shih et al. 2016: 159, 174 [part], fig. 12A; Baakdah 2018: 51; AAJ Kumar 2019: 54.

Tubuca alcocki Shih, Chan & Ng, 2018: 49 , figs. 3, 4A, C, 5A–D, 6, 7A, C, E, G (type locality: Ranong, Thailand); Beleem et al. 2019: 15; Sasaki 2019: 12507.

Tubuca dussumieri – Beleem et al. 2019: 15; Pati et al. 2022: 529.

Tubuca acuta – Beleem et al. 2019: 15.

Tubuca (Tubuca) alcocki – Rosenberg 2019: 735.

Material examined: Holotype: ò ( CW 30.1 mm, CL 17.9 mm; PL 58.2 mm) ( ZRC 2017.1278 ), Ranong mangroves, Thailand, coll. H.- T. Shih et al., 27 May 2012 . Paratypes: 2 òò ( CW 22.4–29.9 mm), 1 ñ ( CW 25.1 mm) (NCHUZOOL 13661), 1 ò ( CW 29.5 mm) (NCHUZOOL 14896), 13 òò ( CW 14.7–31.2 mm), 4 ññ ( CW 19.9–24.1 mm), 1 ovig. ñ ( CW 25.7 mm) (NCHUZOOL 14905), same data as holotype; 1 ò ( CW 24.6 mm), 1 ovig. ñ ( CW 14.8 mm) ( ZRC 2017.1279), Kamphuan mangroves, Ranong, Thailand, 9 Sep. 2000; 1 ò ( CW 24.0 mm) ( ZRC 2001.2347), Ranong, Thailand, coll. P. Clark, 7 Nov. 2001.

Saudi Arabia: 2 òò (19.1, 22.9 mm) (NCHUZOOL 14904), Al Darb (17°26'53.4"N; 17°26' 53.4"N), coll. A. J. Kumar, 25 Apr. 2017. Pakistan: 2 òò (32.6, 33.9 mm), 1 ò (broken) (NCHUZOOL 15097), Sandspit, Karachi, coll. N. U. Saher, 10 Dec. 2020. India: 1 ò ( CW 17.7 mm) (NCHUZOOL 14925), 1 ò ( CW 19.0 mm) (NCHUZOOL 14899), 1 ò ( CW 12.6 mm) (NCHUZOOL 14901), 1 ñ ( CW 17.5 mm) (NCHUZOOL 14902), 13 òò ( CW 9.9–18.2 mm), 3 ññ ( CW 11.4–17.9 mm), 1 ovig. ñ ( CW 19.9 mm) (NCHUZOOL 14903), Mumbai, coll. H.-N. Chen et al., 17 Mar. 2010; 1 ñ ( CW 22.6 mm) (NCHUZOOL 14900), Diu mangroves, coll. K. Wong, 20 Mar. 2010; 3 òò (13.4–14.4 mm) (NCHUZOOL 15098), 1 ò (16.2 mm) (NCHUZOOL 15099), 2 òò (16.5– 13.1 mm), 2ññ (14.5– 9.8 mm), (CASAU- CR-1014), Sunkeri mangroves, Karwar, Karnataka, coll. M. Prema, 4 Feb. 2021.

Distribution: Western Saudi Arabia, Pakistan, India, Bangladesh and western Thailand.

Remarks: The two species of Tubuca recorded from the WIO, T. urvillei and T. alcocki , are sister species with allopatric distributions. The former is restricted to the southwestern Indian Ocean , while the latter ranges widely in the northern Indian Ocean ( Shih et al. 2018) , their ranges are separated around the Somali Peninsula. COI data shows genetic homogeneity across the range of this species from the Red Sea to Thailand ( Fig. 4 ).

A key to the genera and species of fiddler crabs in northwestern Indian Sea

1. Front narrow; outer surface of major cheliped manus with tubercles ..................................................................................... 2

- Front wide; outer surface of major cheliped manus smooth ...... 4

2. Outer major cheliped dactylus with groove; major carpus with delimited anterodorsal area flattened; major chela equally likely to be left or right; orbital floor often with tubercles, ridge or mound ............................................................ Tubuca ( T. alcocki )

- Outer major cheliped dactylus without groove; major carpus without delimited anterodorsal area flattened; major chela on right side> 90% of the time; orbital floor without sculpture ........ ................................................................................. 3 ( Gelasimus )

3. Outer surface of major cheliped manus with small tubercles; fingers narrow and thick; outer pollex without groove; female with carapace sides pilose toward posterior ........... G. tetragonon

- Outer surface of major cheliped manus with large tubercles; fingers broad and flat; outer pollex with one groove; female carapace sides lacking pile ....................................... G. hesperiae

4. Major cheliped with large subdistal tooth on cutting edge of dactylus ....................................................... Cranuca ( C. inversa )

- Major cheliped without large subdistal tooth on cutting edge of dactylus ..................................................................... 5 ( Austruca )

5. Major cheliped without oblique granular ridge on inner surface of palm; immovable finger without subdistal tooth on cutting edge ..................................................................................................... 6

- Major cheliped with oblique granular ridge on inner surface of palm; immovable finger with distinct subdistal tooth on cutting edge ............................................................................................ 7

6. Anterolateral angles of carapace acute, directed laterally; major cheliped with fingers slender, without large proximal tooth on cutting margin of fingers ........................................... A. sindensis

- Anterolateral angles of carapace broadly triangular, directed anteriorly; major cheliped with fingers broad, large proximal tooth on each cutting margin of finger ..................... A. variegata

7. Major chela with supramarginal groove adjacent to lower border on outer surface of palm ........................................... A. annulipes

- Major chela without supramarginal groove adjacent to lower margin of palm ........................................................................... 8

8. Carapace with lateral margins nearly straight; major chela without large proximal tooth on cutting margin of fingers ........... ....................................................................................... A. iranica

- Carapace with lateral margins slightly converging distally; major chela with large proximal tooth on each cutting margin of finger .................................................................................... A. albimana

Figures

Fig. 3. Dorsal view of carapace and frontal view of major cheliped. Cranuca inversa (A, B, NCHUZOOL 15093, CW 19.9 mm, 18.7 mm, Saudi Arabia); Gelasimus hesperiae (C, D, MNHN-IU-2011-5608, CW 20.3 mm, Djibouti); G. tetragonon (E, F, NCHUZOOL 15096, CW 32.5 mm, Egypt); Tubuca alcocki (G, NCHUZOOL 14904, CW 19.1 mm, Saudi Arabia; H, NCHUZOOL 15097, CW 33.9 mm, Pakistan).

Fig. 4. COI neighbor-joining tree for fiddler crabs studied, with bootstrap support values (only> 50% shown).