Tubuca typhoni ( Crane, 1975 )

Shih, Hsi-Te, Wong, Kingsley J. H., Chan, Benny K. K., Nguyen, Thanh Son, Do, Van Tu, Ngo, Xuan Quang & Hsu, Pei-Yi, 2022, Branchipolynoe onnuriensis Kim & Choi & Eyun & Kim & Yu 2022, sp. nov., Zoological Studies 61 (66), pp. 1-24 : 16-17

Tubuca typhoni ( Crane, 1975) ( Fig. 6C, D )

Uca (Deltuca) demani typhoni Crane, 1975: 41 , 593, fig. 61C, pl. 4E– H (type locality: Manila, Luzon).

Uca typhoni – Do 2003: 8; Shih et al. 2010b: 13, figs. 4A, B, 5A, C.

Uca (Tubuca) typhoni – Ng et al. 2008: 242.

Tubuca typhoni – Shih et al. 2016b: 159, 174; Sasaki 2019: 12525.

Tubuca (Tubuca) typhoni – Rosenberg 2019: 735.

Material examined: Binh Thuan: 1 ò (23.0 mm) (NCHUZOOL 15150), Nguyen Thong, Phu Hai, Phan Thiet, coll. I-H. Chen et al. 26 Nov. 2010. Ho Chi Minh: 1 ò (17.5 mm) (NCHUZOOL 15151), Rung Sac, Long Hoa, Can Gio, coll. H.- T. Shih and P.-Y. Hsu, 12 Oct. 2017.

Distribution: Northern Philippines, South China (Hainan) and southern Vietnam.

Remarks: Tubuca typhoni is distributed sporadically in northern Philippines, southern Hainan in China and the Mekong Delta in southern Vietnam ( Crane 1975; Shih et al. 2010b; this study). This species has been included in the list of brachyuran fauna collected from southern Vietnam, albeit the lack of illustrations ( Do 2003). With both morphological and molecular evidence, our report confirms the presence of this species from southern Vietnam.

A key to the genera and species of fiddler crabs in Vietnam

1. Front narrow; outer major manus tubercular .............................. 2

- Front wide; outer major manus smooth .................................... 11

2. Outer major dactylus without groove; major carpus without delimited anterodorsal area flattened; more than 90% of males with major chela on the right; orbital floor without any elevations ................................................................................. 3 ( Gelasimus )

- Outer major dactylus with 1 to 2 grooves; major carpus with delimited anterodorsal area flattened; roughly 50% of males with major chela on either side; orbital floor often with tubercles, ridge or mound ..................................................................... 5 ( Tubuca )

3. Outer major manus with small tubercles; fingers narrow and thick; outer pollex without groove; female with pile posteriorly on carapace sides .................................................... G. tetragonon

- Outer surface of major manus with large tubercles; fingers broad and flat; outer pollex with one groove; female without pile posteriorly on carapace sides ...................................................... 4

4. Major pollex with shallow or without distal depression in gape, dactyl deeper than pollex only in young; oblique ridge of inner major manus low ........................................................ G. borealis

- Major pollex with both deep proximal and distal depressions in gape, dactyl not deeper than pollex; oblique ridge of inner major manus high ................................................................... G. vocans

5. Meri of first 3 ambulatory legs broad ......................................... 6

- Meri of first 3 ambulatory legs slender .................................... 10

6. Floor of orbit with a row of tubercles; anterolateral margin shorter ........................................................................... T. typhoni

- Floor of orbit without a row of tubercles; anterolateral margin longer .......................................................................................... 7

7. Carapace strongly arched; large size (up to CW ~ 37 mm); major manus with large tubercles, fingers with a series of slightly enlarged predistal teeth (<1/4 length of inner margins of fingers) in pollex and dactyl, or absent; young male with short fingers .. 8

- Carapace not strongly arched; small size (up to CW ~ 20 mm); major manus with small tubercles, fingers slender, with a series of slightly enlarged predistal teeth (near 1/2 length of inner margins of fingers) in pollex and dactyl ..................................... 9

8. Ambulatory legs broader; major manus with large tubercles covering entire surface; G1 with relatively narrower genital opening and broad posterior flanges ............................. T. arcuata

- Ambulatory legs narrower; major manus with large tubercles covering upper surface; G1 with relatively wider genital opening and vestigial flanges ................................................... T. forcipata

9. Groove of front broader, with sides not convergent distally; suborbital granules detectable; tubercles on outer manus larger ... .......................................................................................... T. acuta

- Groove of front narrower, with sides convergent distally; suborbital granules absent; tubercles on outer manus smaller ...... ................................................................................ T. rhizophorae

10. Front with distinct narrow median groove; G1 with distal tuberculate chitinous process; female without large tooth on either finger in gape; large size (up to CW ~ 38 mm) .................... .......................................................................... T. paradussumieri

- Front almost without discernible median groove, but clearly separated; G1 with distal blunt chitinous process; female always with a large tooth on both fingers in gape; medium size (up to CW ~ 27 mm) ........................................................... T. dussumieri

11. A shallow, triangular depression outside major pollex base; fourth ambulatory merus broad, its dorsal margin convex ...................... ............................................................ Paraleptuca ( P. splendida )

- No triangular depression outside major pollex base; fourth ambulatory merus slender, its dorsal margin straight .................... ................................................................................. 12 ( Austruca )

12. Anterolateral angles triangular; major pollex without or with small predistal triangular tooth in gape; major dactyl arched throughout; G1 with thumb long, reaching well beyond flange base, flange wider than long ........................................... A. lactea

- Anterolateral angles moderately acute; major pollex with moderate to large predistal triangular tooth in gape; major dactyl arched only distally; G1 with thumb moderately long, reaching flange base, flange wider than long ............................ A. perplexa

- Anterolateral angles strongly acute; major pollex with small to moderate predistal triangular tooth in gape; major dactyl arched throughout; G1 with thumb short, not reaching flange base, flange remarkably long ........................................................ A. annulipes

Figures

Fig. 6. Dorsal view of carapace and frontal view of major cheliped. Tubuca rhizophorae (A, B, NCHUZOOL 15148, CW 15.4 mm, Can Gio, Ho Chi Minh City); T. typhoni (C, D, NCHUZOOL 15151, CW 17.5 mm, Can Gio, Ho Chi Minh City).