Leptuca Bott, 1973

Shih, Hsi-Te, Ng, Peter K. L., Davie, Peter J. F., Schubart, Christoph D., Türkay, Michael, Naderloo, Reza, Jones, Diana & Liu, Min-Yun, 2016, Systematics of the family Ocypodidae Rafinesque, 1815 (Crustacea: Brachyura), based on phylogenetic relationships, with a reorganization of subfamily rankings and a review of the taxonomic status of Uca Leach, 1814, sensu lato and its subgenera, Raffles Bulletin of Zoology 64, pp. 139-175 : 153-154

Leptuca Bott, 1973 , status nov.

( Fig. 9B–F )

Leptuca Bott, 1973b: 324 . Type species: Gelasimus stenodactylus H. Milne Edwards & Lucas, 1843 , by original designation. Gender feminine.

Celuca Crane, 1975: 211 . Type species: Uca deichmani Rathbun, 1935 , by original designation. Gender feminine.

Planuca Bott, 1973b: 324 . Type species: Uca thayeri Rathbun, 1900 , by original designation. Gender feminine.

Boboruca Crane, 1975: 109 . Type species: Uca thayeri Rathbun, 1900 , by original designation. Gender feminine.

Diagnosi s. Small- to large-sized species (carapace width about 5–25 mm in adults); anterolateral margins short; 0–2 posterolateral striae on dorsal carapace surface; front broad; cornea round; eyestalks slender; adult male major cheliped very large, right- or left-handed, pollex sometimes with ventral carina, outer surface of major manus smooth; male pleonites free or somites 4–6 partly or fully fused; pleonal locking mechanism absent; gastric mill with 2 large brownish setae at base of posterior tooth plate. Confined to the Atlantic and East Pacific coasts of the Americas.

Species included:

1. Leptuca batuenta ( Crane, 1941)

2. Leptuca beebei ( Crane, 1941)

3. Leptuca coloradensis ( Rathbun, 1893)

4. Leptuca crenulata ( Lockington, 1877)

= Gelasimus gracilis Rathbun, 1893

5. Leptuca cumulanta ( Crane, 1943)

6. Leptuca deichmanni ( Rathbun, 1935)

7. Leptuca dorotheae ( von Hagen, 1968)

8. Leptuca festae ( Nobili, 1902)

= Uca guayaquilensis Rathbun, 1935

= Uca orthomana Bott, 1954

= Uca leptochela Bott, 1954

= Uca leptochela eibli Bott, 1958

9. Leptuca helleri ( Rathbun, 1902)

10. Leptuca inaequalis ( Rathbun, 1935)

11. Leptuca latimanus ( Rathbun, 1893)

12. Leptuca leptodactyla (Rathbun, in Rankin, 1898)*

13. Leptuca limicola ( Crane, 1941)

14. Leptuca musica ( Rathbun, 1914)

15. Leptuca oerstedi ( Rathbun, 1904)

16. Leptuca panacea ( Novak & Salmon, 1974)

17. Leptuca pugilator (Bosc, 1802)

= Ocypode citharoedicus Say, 1817 (unavailable name)

18. Leptuca pygmaea ( Crane, 1941)

19. Leptuca saltitanta ( Crane, 1941)

20. Leptuca speciosa ( Ives, 1891)

21. Leptuca spinicarpa ( Rathbun, 1900)

22. Leptuca stenodactylus (H. Milne Edwards & Lucas, 1843)

= Gelasimus gibbosus Smith, 1870

23. Leptuca subcylindrica ( Stimpson, 1859)

24. Leptuca tallanica ( von Hagen, 1968)

25. Leptuca tenuipedis ( Crane, 1941)

26. Leptuca terpsichores ( Crane, 1941)

27. Leptuca thayeri ( Rathbun, 1900)

28. Leptuca tomentosa ( Crane, 1941)

= Uca mertensi Bott, 1954

29. Leptuca umbratila ( Crane, 1941)

= Uca thayeri zilchi Bott, 1954

30. Leptuca uruguayensis (Nobili, 1901)

= Uca olympioi Oliveira, 1939

* This name has been sometimes spelt as ‘ leptodactylus ’ following the original unpublished manuscript name of Guérin (see Ng et al., 2008). Rathbun’s original spelling, however, was “ leptodactyla ”, and this should be followed (see Chace & Hobbs, 1969: 212; Crane, 1975: 306; ICZN, 1999: Article 31.2.2).

Remarks. The results of the present genetic analyses show two distinct clades for the American BF genera Leptuca and Minuca , thus supporting their validity. These two genera (including U. thayeri and U. umbratila , see below) can, for the most part, be separated morphologically with the characters stated in the diagnosis. However, the placement of some species has proven problematic (see examples in Beinlich & von Hagen, 2006). The species constitution of Leptuca has been partially discussed by Shih et al. (2015), and noteworthy is the transfer from Minuca to Leptuca of L. subcylindrica , L. thayeri and L. umbratila ; the close relationships between L. panacea and L. pugilator , and between L. thayeri , L. umbratila and L. spinicarpa ; as well as the establishment of Petruca for Gelasimus panamensis (see Remarks under Petruca ).

Several authors have tried to separate Leptuca and Minuca by characters such as the shape of the anterolateral margins and number of posterolateral striae on the carapace, the degree of fusion of pleonites 4–6, the presence of a ventral carina on the major pollex, and the shapes of the G1 ( Crane, 1975; Rosenberg, 2001; Beinlich & von Hagen, 2006; Bezerra, 2012). Despite this, there are still no consistently useful characters to reliably define the genera. Similarly, earlier 16S genetic analyses were unable to resolve their relationships ( Levinton et al., 1996; Sturmbauer et al., 1996). Minuca has been considered a smaller “homogeneous” group, compared to the more speciose “heterogeneous” Leptuca ( Barnwell & Thurman, 1984; Beinlich & von Hagen, 2006; Ng et al., 2008).

There are presently 30 species within Leptuca which makes it the most diverse genus within the family. Leptuca species are more widely distributed in the Americas than those of Minuca and Uca ( Fig. 4 ). Because fewer than half (14) species of Leptuca were analysed for this study, it is vital that more species are examined and sequenced in the future to confirm their generic position, and to further clarify their relationships within the genus. This is an aspect which will need further study.

Figures

Fig. 9. Photographs of some species of the genera Cranuca, Leptuca and Minuca. A, C. inversa (East Africa); B, L. deichmanni (Panama); C, L. speciosa (Bahamas); D, L. terpsichores (Panama); E, L. thayeri (Brazil); F, L. umbratila (Panama); G, M. brevifrons (Costa Rica); H, M. burgersi (Bahamas). A, courtesy of S. Cannicci.

Fig. 4. The distribution of 11 genera of fiddler crabs, mainly based on Crane (1975) and the website (http://www.fiddlercrab.info/index. html; Rosenberg, 2014).