Acknowledgements
We are indebted to the members of the Giribet lab, especially to Shahan Derkarabetian for his advice during lab work and UCEs assembly. We are also grateful to the Bauer Core and the RC Computing team. We are especially thankful to Tauana J. Cunha and the MaRHE Center staff for their help while collecting in the Maldives and for providing photographs of live specimens. We appreciate the samples donated from the GROC Association (https://opistobranquis.org/en/home) and M. A. E. Malaquias (University Museum of Bergen). Specimen collection was funded by a Putnam Expedition Grant from the Museum of Comparative Zoology to JM. Lab and analytical work were supported by internal funds from the Faculty of Arts and Sciences, Harvard University, to GG. JM postdoctoral fellowships were supported by the Ramón Areces (Spain) and the Alexander von Humboldt (Germany) Foundations.