Squat lobsters (Decapoda: Chirostyloidea and Galatheoidea) from Saya de Malha Bank, SW Indian Ocean, with the descriptions of three new species
Abstract
Specimens of galatheoid and chirostyloid squat lobsters were collected during a scientific cruise to the Saya de Malha Bank in the southwestern Indian Ocean. Nineteen species were identified, including three new species belonging to the genera Coralliogalathea Baba & Javed, 1974, Galathea Fabricius, 1793 and Trapezionida Macpherson & Baba, 2022. The present paper provides systematic accounts of the three new species, along with new locality records of other species. Molecular data are provided to support the identification and differentiation of each new species.
References
Baba K. 1990. Chirostylid and galatheid crustaceans of Madagascar (Decapoda, Anomura). Bulletin du Muséum national d’Histoire naturelle, (4e série) Section A 11: 921–975. https://doi.org/10.5962/p.288276
Baba K., Macpherson E., Poore G.C.B., Ahyong S.T., Bermudez A., Cabezas P., Lin C.W., Nizinski M., Rodrigues C. & Schnabel K.E. 2008. Catalogue of squat lobsters of the world (Crustacea: Decapoda: Anomura – families Chirostylidae, Galatheidae and Kiwaidae). Zootaxa 1905: 1–220. https://doi.org/10.11646/zootaxa.1905.1.1
Baba K., Macpherson E., Lin C.W. & Chan T.-Y. 2009. Crustacean Fauna of Taiwan. Squat Lobsters (Chirostylidae and Galatheidae). National Taiwan Ocean University, Keelung.
Baba K., Ahyong S.T. & Macpherson E. 2011. Morphology of the marine squat lobsters. In: Poore G.C.B., Ahyong S.T. & Taylor J. (eds) The Biology of Squat Lobsters: 1–37. CSIRO Publishing, Melbourne and CRC Press, Boca Raton.
Baba K., Corbari L. & Macpherson E. 2024. Chirostylidae of the western Indian Ocean (Crustacea: Decapoda: Anomura). In: Tropical Deep-Sea Benthos, vol 34: Deep-Sea Chirostylids and Stylasterids from South-West Indian Ocean. Mémoires du Muséum national d’Histoire naturelle 218: 13–221. https://doi.org/10.5852/mem218
Bergstad O.A., Tabachnick K., Rybakova E., Gendron G., Souffre A., Bhagooli R., Ramah S., Olsen M., Hoines A.S. & Dautova T. 2021. Macro-and megafauna on the slopes of the Saya de Malha Bank of the Mascarene Plateau. Western Indian Ocean Journal of Marine Science 2/2021: 129–158. https://doi.org/10.4314/wiojms.si2021.2.10
Bhagooli R., Ramah S., Gendron G., Kaullysing D., Caussy L. & Mostarda E. 2024. Marine Biodiversity of the Saya de Malha Bank Shallows: A Photographic Catalogue. FAO, Rome. https://doi.org/10.4060/cd3735en
Borradaile L.A. 1910. Penaeidea, Stenopidea, and Reptantia from the Western Indian Ocean. In: The Percy Sladen Trust Expedition to the Indian Ocean in 1905, under the leadership of Mr. J. Stanley Gardiner. Volume 2, no. 10. Transactions of the Linnean Society of London, Zoology, Series 2 13: 257–264. https://doi.org/10.1111/j.1096-3642.1910.tb00517.x
Botha T.P.A., Griffiths C.L., Atkinson L.J. & Macpherson E. 2025. The Galatheidae (Anomura: Galatheoidea) of South Africa, with a description of a new species. Zootaxa 5661 (3): 330–350. https://doi.org/10.11646/zootaxa.5661.3.2
Burukovsky R.N. 1993. Shrimps of the Saya de Malha Bank (the Indian Ocean). Zoologicheskii Zhurnal 72: 20–28. [In Russian.]
Cabezas P., Macpherson E. & Machordom A. 2011. Allogalathea (Decapoda: Galatheidae): A monospecific genus of squat lobsters? Zoological Journal of the Linnean Society 156: 465–493. https://doi.org/10.1111/j.1096-3642.2008.00492.x
Cabezas P., Sanmartín I., Paulay G., Macpherson E. & Machordom A. 2012. Deep under the sea: Unraveling the evolutionary history of the deep-sea squat lobster Paramunida (Decapoda, Munididae). Evolution 66: 1878–1896. https://doi.org/10.1111/j.1558-5646.2011.01560.x
Chen C.L. & Chan T.Y. 2023. The use of three-dimensional μCT imaging technique in the description of a new species of Stenopus Latreille, 1819 (Decapoda: Stenopodidea: Stenopodidae), with a revised key to the species of Stenopus. Journal of Crustacean Biology 43: ruad041. https://doi.org/10.1093/jcbiol/ruad041
Corbari L., Bouchet P., Le Gall L., Hourdez S., Frutos I., Gouillieux B., Vassard E., Moutardier G., Chen W.-J., Ng S.-L., Bhagooli R., Ramah S., Kaullysing D., Munbodhe V., Labonte C., Boone R. & Bender S. 2025. New insights in benthic biodiversity of the Saya de Malha Bank. Deep Sea Research Part II 222: 105500. https://doi.org/10.1016/j.dsr2.2025.105500
Fabricius J.C. 1793. Entomologia systematica emendata et aucta. Secundum classes, ordines, genera, species adjectis synonymis, locis; observatiosnibus, descriptionibus. Impensis Christ. Gottl. Proft., Kopenhagen [Hafniae]. https://doi.org/10.5962/bhl.title.122153
Folmer O., Black M., Hoeh W., Lutz R. & Vrijenhoek R. 1994. DNA primers for amplification of mitochondrial cytochrome c oxidase subunit I from diverse metazoan invertebrates. Molecular Marine Biology and Biotechnology 3: 294–299.
Galil B.S. 2025. Long time no see – 117 years after its first and only record Praebebalia extensiva Rathbun 1911 (Decapoda, Lecosiidae) was collected from Saya de Malha. Western Indian Ocean Journal of Marine Science 24 (1): 39–42. https://doi.org/10.4314/wiojms.v24i1.5
Machordom A., Ahyong S.T., Andreakis N., Baba K., Buckley D., García-Giménez R., McCallum A.W., Rodríguez-Flores P.C. & Macpherson E. 2022. Deconstructing the crustacean squat lobster genus Munida to reconstruct the evolutionary history and taxonomy of the family Munididae (Crustacea, Anomura, Galatheoidea). Invertebrate Systematics 36: 926–970. https://doi.org/10.1071/IS22013
Macpherson E. 1994. Crustacea Decapoda: Studies on the genus Munida Leach, 1820 (Galatheidae) in New Caledonia and adjacent waters with descriptions of 56 new species. In: Crosnier A. (ed.) Résultats des Campagnes MUSORSTOM, Vol. 12. Mémoires du Muséum national d’Histoire naturelle 161: 421–569.
Macpherson E. & Baba K. 2011. Taxonomy of squat lobsters. In: Poore G.C.B., Ahyong S.T. & Taylor J. (eds) The Biology of Squat Lobsters: 39–71. CSIRO Publishing, Melbourne and CRC Press, Boca Raton.
Macpherson E. & Robainas-Barcia A. 2015. Species of the genus Galathea Fabricius, 1793 (Crustacea, Decapoda, Galatheidae) from the Indian and Pacific Oceans, with descriptions of 92 new species. Zootaxa 3913: 1–335. https://doi.org/10.11646/zootaxa.3913.1.1
Macpherson E., Rodríguez-Flores P.C. & Machordom A. 2017. New sibling species and new occurrences of squat lobsters (Crustacea, Decapoda) from the western Indian Ocean. European Journal of Taxonomy 343: 1–61. https://doi.org/10.5852/ejt.2017.343
Macpherson E., Rodríguez-Flores P.C. & Machordom A. 2023. A checklist of the Galatheoid squat lobsters from the South–West Indian Ocean (Decapoda: Anomura: Galatheoidea), with the description of four new species. In: Corbari L., Richers de Forges B. & Macpherson E. (eds) Tropical Deep–Benthos, Vol. 33. Mémoires du Muséum national d’Histoire naturelle 217: 351–392.
Macpherson E., Rodríguez-Flores P.C. & Machordom A. 2025. New species of Galathea Fabricius, 1793 and Nanogalathea Tirmizi & Javed, 1980 (Crustacea: Decapoda, Galatheidae) from the Western Pacific. Zootaxa 5570: 447–483. https://doi.org/10.11646/zootaxa.5570.3.2
Obura D.O., Church J.E. & Gabrié C. 2012. Assessing Marine World Heritage from an Ecosystem Perspective: The Western Indian Ocean. World Heritage Centre, United Nations Education, Science and Cultural Organization (UNESCO).
Puillandre N., Macpherson E., Lambourdière J., Cruaud C., Boisselier-Dubayle M.C. & Samadi S. 2011. Barcoding type specimens helps to identify synonyms and an unnamed new species in Eumunida Smith, 1883 (Decapoda, Eumunididae). Invertebrate Systematics 25: 322–333. https://doi.org/10.1071/IS11022
Ramah S., Gendron G., Bhagooli R., Soondur M., Souffre A., Melanie R., Coopen P., Caussy L., Bissessur D. & Bergstad O.A. 2021. Diversity and distribution of the shallow water (23–50 m) benthic habitats on the Saya de Malha Bank, Mascarene Plateau. Western Indian Ocean Journal of Marine Science 2/2021: 69–80. https://doi.org/10.4314/wiojms.si2021.2.5
Rathbun M.J. 1911. Marine Brachyura. In: The Percy Sladen Trust expedition to the Indian Ocean in 1905, under the leadership of Mr. J. Stanley Gardiner. Volume III. No. XI. Transactions of the Linnean Society of London, Zoology, Series 2 14 (2): 191–261. Available from https://www.biodiversitylibrary.org/page/16422294 [accessed 23 Jul. 2025].
Rodríguez-Flores P.C., Macpherson E., Buckley D. & Machordom A. 2018. High morphological similarity coupled with high genetic differentiation in new sympatric species of coral-reef squat lobsters (Crustacea: Decapoda: Galatheidae). Zoological Journal of the Linnean Society 185: 984–1017. https://doi.org/10.1093/zoolinnean/zly074
Rodríguez-Flores P.C., Macpherson E., Schnabel K., Ahyong S.T., Corbari L. & Machordom A. 2022. Depth as a driver of evolution and diversification of ancient squat lobsters (Decapoda, Galatheoidea, Phylladiorhynchus). Molecular Phylogenetics and Evolution 171: e107467. https://doi.org/10.1016/j.ympev.2022.107467
Rodríguez-Flores P.C., Torrado H., Combosch D. &. Giribet G. 2024. Diversity of squat lobsters on coral reefs in Guam, Mariana Islands, with the description of two new species and notes on their natural history. Marine Biodiversity 54: 57. https://doi.org/10.1007/s12526-024-01446-4
Schnabel K.E., Cabezas P., McCallum A., Macpherson E., Ahyong S.T. & Baba K. 2011. World-wide distribution patterns of squat lobsters. In: Poore G.C.B., Ahyong S.T. & Taylor J. (eds) The Biology of Squat Lobsters: 149–182. CSIRO Publishing: Melbourne and CRC Press: Boca Raton.
Spiridonov V.A. & Türkay M. 2001. Deep sea swimming crabs of the Charybdis miles species group in the western Indian Ocean (Crustacea: Decapoda: Portunidae). Journal of Natural History 35: 439–469. https://doi.org/10.1080/002229301300009649
Swofford D.L. 2004. PAUP 4.0 for Macintosh: Phylogenetic Analysis Using Parsimony (software and user’s book for Macintosh).
Vortsepneva E. 2008. Saya de Malha Bank – An invisible island in the Indian Ocean. Available from https://lighthouse-foundation.org/Binaries/Binary1070/Saya-de-Malha-report-final.pdf [accessed 23 Jul. 2025].
Watling L. 1989. A classification system for crustacean setae based on the homology concept. In: Felgenhauer B.E., Thistle A.B. & Watling L. (eds) Functional Morphology of Feeding and Grooming in Crustacea: 15–26. CRC Press, London. https://doi.org/10.1201/9781003079354
Zuccon D., Brisset J., Corbari L., Puillandre N., Utge J. & Samadi S. 2012. An optimised protocol for barcoding museum collections of decapod crustaceans: A case-study for a 10–40-years-old collection. Invertebrate Systematics 26: 592–600. https://doi.org/10.1071/IS12027
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