The curious case of Neotroglocarcinus dawydoffi (Decapoda, Cryptochiridae): unforeseen biogeographic patterns resulting from isolation

Abstract

Coral gall crabs form a commonly overlooked component of the associated fauna of shallow-water reef corals and therefore little is known about their ecology and biogeography. This study investigated the biogeography and phylogenetic position of the informal ‘Detocarcini’ species group within the Cryptochiridae. We used molecular data for two mitochondrial markers (COI and 16S) obtained from gall crabs covering (part of) a wide geographic range: the Red Sea, Malaysia, Indonesia and New Caledonia. Our phylogeny reconstructions portrayed the ‘Detocarcini’ as paraphyletic within the monophyletic Cryptochiridae. A phylogeographic clustering was noticed in Neotroglocarcinus dawydoffi that was absent in its sister species, N. hongkongensis, and the closely related species Pseudocryptochirus viridis. A Neighbour Network was estimated for the N. dawydoffi dataset to visualize the similarity between sequences from different biogeographic areas, resulting in three groupings: (1) New Caledonia with Lembeh/Ternate (eastern Indonesia), (2) Semporna/Kudat (eastern Malaysia), and (3) Red Sea (Saudi Arabia). Cryptic speciation rather than isolation is discussed and rejected as an alternative explanation for the observed biogeographic pattern.

Key words:

• 16S
• COI
• distribution records
• phylogeography
• Pseudocryptochirus
• speciation

Acknowledgements

The fieldwork in Raja Ampat (2007) and Ternate (2009) was organized by Naturalis and the Indonesian Institute of Sciences (LIPI), under the umbrella of Ekspedisi Widya Nusantara (E-Win). We thank Professor Farnis Boneka and Professor Markus Lasut (Universitas Sam Ratulangi) for their help during fieldwork in Bunaken (2008). The Marine Biodiversity Workshop in Lembeh Strait (2012) was organised by Naturalis, the Indonesian Institute of Sciences (LIPI), and Universitas Sam Ratulangi. We are grateful to LIPI and RISTEK for granting research permits. The 2010 Semporna Marine Ecological Expedition (SMEE) was jointly organized by WWF-Malaysia, Universiti Malaysia Sabah's Borneo Marine Research Institute, Universiti Malaya's Institute of Biological Sciences and Naturalis Biodiversity Center. The research permits for Malaysia were granted by the Prime Minister's Department, Economic Planning Unit Sabah, Sabah Parks and Department of Fisheries Sabah. The 2012 Tun Mustapha Park expedition (TMP) was jointly organized by WWF-Malaysia, Universiti Malaysia Sabah (UMS), Sabah Parks and Naturalis Biodiversity Center, the Netherlands. The research permits were granted by the Economic Planning Unit, Prime Minister's Department Malaysia and Sabah Biodiversity Centre. Fieldwork in the Red Sea (March 2013 Marine Biodiversity Cruise) was supported by the King Abdullah University of Science and Technology (KAUST) under the Biodiversity in the Saudi Arabian Red Sea programme, award number CRG-1-BER-002 to M.L. Berumen. Collecting in New Caledonia (2013) during the mission CORALCAL 4 by Bert Hoeksema (Naturalis) was possible thanks to IRD Noumea. Provinces Sud and Nord of New Caledonia provided sampling permits. We thank Dick Groenenberg and Charles Fransen (Naturalis) for discussions in an earlier stage of the manuscript. We gratefully acknowledge two anonymous reviewers for their remarks, which substantially improved the manuscript.

Associate Editor: Joanne S. Porter

Supplemental data

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Additional information

Funding

Funding for fieldwork in Indonesia was provided by the A.M. Buitendijkfonds, L.B. Holthuisfonds, J.J. ter Pelkwijkfonds (all Naturalis), Stichting Fonds Doctor Catharine van Tussenbroek (Nell Ongeboerfonds), Schure-Beijerinck-Poppingfonds (KNAW) and the Van Tienhoven Foundation for International Nature Protection. SMEE2010 was funded through WWF-Malaysia. TMP2012 was funded by the Malaysian Ministry of Science, Technology and Innovation and USAID Coral Triangle Support Partnership. The fieldwork in the Red Sea was sponsored by KAUST. The COI sequences were produced as part of the Naturalis Barcoding project.