Exploring carapace phenotypic variation in female Fiddler Crab Austruca annulipes (H. Milne Edwards, 1837): insights into adaptive strategies and ecological significance
DOI:
https://doi.org/10.11609/jott.9161.17.10.27754-27760Keywords:
Alternative reproductive tactics, behaviour, carapace pattern, colour variation, mangrove, morphology, moulting, Ocypodidae, polymorphism, sexual dimorphismAbstract
Fiddler crabs (Ocypodidae: Crustacea: Arthropoda) are globally documented but relatively understudied along the Indian coastline. Austruca annulipes, common across Indian mangrove habitats, remains insufficiently explored in terms of female morphology. While male fiddler crabs are recognized for their prominent chelae, females of A. annulipes exhibit notable polymorphism. In this short-term study conducted in the mangroves of Sauta Vaddo (Baga), Goa, we documented 14 distinct female morphs, alongside observations of male moulting. The study highlights the scope for future research into the adaptive significance of female phenotypic variation in this species.
References
Bouchard, J., J. Poupin, R. Cleva, J. Dumas & V. Dinhut (2013). Land, mangrove and freshwater decapod crustaceans of Mayotte region (Crustacea Decapoda). Atoll Research Bulletin 592: 1–60. https://doi.org/10.5479/si.00775630.592
Brown, F.A. & H.M. Webb (1949). Studies of the Daily Rhythmicity of the Fiddler Crab, Uca. Modifications by Light. Physiological Zoology 22(2): 136–148. https://doi.org/10.1086/physzool.22.2.30152036
Crane, J. (1944). On the colour changes of Fiddler crabs (Genus Uca) in the field. Zoologica Scientific Contributions of the New York Zoological Society 29(15): 161–168. https://doi.org/10.5962/p.203572
Crane, J. (1958). Aspects of social behavior in fiddler crabs, with special reference to Uca maracoani (Latreille). Zoologica Scientific Contributions of the New York Zoological Society 43(10): 113–130. https://doi.org/10.5962/p.203380
Crane, J. (2015). Fiddler Crabs of the World: Ocypodidae: Genus UCA. Princeton University Press, 766 pp.
Darnell, M.Z., P.R. Backwell & P. Munguia (2019). Frequency and latency of autotomy of a sexually selected fiddler crab appendage. Journal of Experimental Marine Biology and Ecology 523: 151255. https://doi.org/10.1016/j.jembe.2019.151255
Detto, T., J.M. Hemmi & P.R.Y. Backwell (2008). Colouration and colour changes of the fiddler crab, Uca capricornis: a descriptive study. PLoS ONE 3(2): e1629. https://doi.org/10.1371/journal.pone.0001629
Diamant, E.S., J.J. Falk & D.R. Rubenstein (2021). Male-like female morphs in hummingbirds: the evolution of a widespread sex-limited plumage polymorphism. Proceedings of the Royal Society B Biological Sciences 288(1945): 1–10. https://doi.org/10.1098/rspb.2020.3004
Fulmali, M., S. Kumaresan, A. Saravanakumar & R. Samuthirapandian (2021). Customisation of bioturbatory structure and spatio-temporal burrow density variations and allometric growth pattern by porcelain fiddler crab (Austruca annulipes H. Milne Edwards, 1837) in polluted and unpolluted habitats of Vellar Estuary, India. Thesis for Master of Science in Marine Biology and Oceanography. Annamalai University.
Hampton, K., M. Hopkins, J. McNamara & C. Thurman (2013). Intraspecific variation in carapace morphology among fiddler crabs (Genus Uca) from the Atlantic coast of Brazil. Aquatic Biology 20(1): 53–67. https://doi.org/10.3354/ab00545
Hemmi, J.M., J. Marshall, W. Pix, M. Vorobyev & J. Zeil (2006). The variable colours of the fiddler crabUca vomerisand their relation to background and predation. Journal of Experimental Biology 209(20): 4140–4153. https://doi.org/10.1242/jeb.02483
Oliveira, R.F., M. Taborsky & H.J. Brockmann (2008). Alternative Reproductive Tactics: An Integrative Approach. Cambridge University Press, 518 pp.
Peer, N., N.A. Miranda & R. Perissinotto (2015). A review of fiddler crabs (genusUcaLeach, 1814) in South Africa. African Zoology 50(3): 187–204. https://doi.org/10.1080/15627020.2015.1055700
Silva, D.J.A., M.F. Erickson & D.M.A. Pessoa (2024). The role of carapace colour in species recognition in a fiddler crab. Animal Behaviour 216: 37–44. https://doi.org/10.1016/j.anbehav.2024.07.016
Tate, G.J. & A. Amar (2017). Morph specific foraging behavior by a polymorphic raptor under variable light conditions. Scientific Reports 7(1): 1–12. https://doi.org/10.1038/s41598-017-07829-x
WoRMS World Register of Marine Species - Austruca annulipes (H. Milne Edwards, 1837). Accessed on 2.vi.2023. https://www.marinespecies.org/aphia.php?p=taxdetails&id=955178#:~:text=DecaNet%20eds.%20(2024).%20DecaNet.%20Austruca%20annulipes%20(H.%20Milne%20Edwards%2C%201837).%20Accessed%20through%3A%20World%20Register%20of%20Marine%20Species%20at%3A%20https%3A//www.marinespecies.org/aphia.php%3Fp%3Dtaxdetails%26id%3D955178%20on%202024%2D02%2D16
Yamaguchi, T. (1977). Studies on the handedness of the fiddler crab, Uca lactea. Biological Bulletin 152(3): 424–436. https://doi.org/10.2307/1540430
Published
Issue
Section
License
Copyright (c) 2025 Vaishnavi Bharti, Sagar Naik, Nitin Sawant

This work is licensed under a Creative Commons Attribution 4.0 International License.
Authors own the copyright to the articles published in JoTT. This is indicated explicitly in each publication. The authors grant permission to the publisher Wildlife Information Liaison Development (WILD) Society to publish the article in the Journal of Threatened Taxa. The authors recognize WILD as the original publisher, and to sell hard copies of the Journal and article to any buyer. JoTT is registered under the Creative Commons Attribution 4.0 International License (CC BY), which allows authors to retain copyright ownership. Under this license the authors allow anyone to download, cite, use the data, modify, reprint, copy and distribute provided the authors and source of publication are credited through appropriate citations (e.g., Son et al. (2016). Bats (Mammalia: Chiroptera) of the southeastern Truong Son Mountains, Quang Ngai Province, Vietnam. Journal of Threatened Taxa 8(7): 8953–8969. https://doi.org/10.11609/jott.2785.8.7.8953-8969). Users of the data do not require specific permission from the authors or the publisher.





