A cryptic radiation of Caribbean sea slugs revealed by integrative analysis: Cyerce ' antillensis ' (Sacoglossa: Caliphyllidae) is six distinct species

• Published in: Zoological journal of the Linnean Society Vol. 200; no. 4; pp. 940 - 979
• Main Authors: Moreno, Karina, Rico, Diane M, Middlebrooks, Michael, Medrano, Sabrina, Valdés, Ángel A, Krug, Patrick J
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.04.2024
• Subjects: Original; heterobranch; species delimitation; gastropod; Caribbean phylogeography; cryptic species
• ISSN: 0024-4082; 1096-3642
• DOI: 10.1093/zoolinnean/zlad111

Integrative studies have revealed cryptic radiations in several Caribbean lineages of heterobranch sea slugs, raising questions about the evolutionary mechanisms that promote speciation within the tropical Western Atlantic. Bergh, 1871 is a genus comprising 12 named species in the family Caliphyllidae that lack the photosynthetic ability of other sacoglossans but are noted for vibrant colours on the large cerata (dorsal leaf-like appendages) that characterize many species. Two species are widely reported from the Caribbean: (Trinchese, 1881) and Engel, 1927. Here, we present an integrative assessment of diversity in Caribbean . Four methods of molecular species delimitation supported seven species in samples from the Caribbean and adjacent subtropical Western Atlantic. Six delimited species formed a monophyletic lineage in phylogenetic analyses but were > 9% divergent at the barcoding locus and could be differentiated using ecological, reproductive and/or morphological traits. We redescribe , a senior synonym for the poorly known Ortea & Templado, 1988, and describe five new species. Evolutionary shifts in algal host use, penial armature and larval life history might have acted synergistically to promote the rapid divergence of endemic species with restricted distributions in this radiation, substantially increasing global diversity of the genus.