The diversity on coral reefs has long captivated observers. We examine the mechanisms of speciation, role of ecology in speciation, and patterns of species distribution in a typical reef-associated clade—the diverse and colorful Calcinus hermit crabs—to address the origin of tropical marine diversity.
We sequenced COI, 16S, and H3 gene regions for ∼90% of 56 putative species, including
nine undescribed, “cryptic” taxa, and mapped their distributions.