Eurythoe complanata (Polychaeta: Amphinomidae), the ‘cosmopolitan’ fireworm, consists of at least three cryptic species

• DOI: 10.1007/s00227-009-1296-9
• Publication Date: 2009-09-16T15:21:19Z
• Authors: Romulo Barroso; Michelle Klautau; Antonio M. Solé-Cava; Paulo C. Paiva
• Keywords: Parapatric speciation; Species complex; Hydrozoa; Cosmopolitan distribution; Genetic algorithm; Genetic divergence; Type locality

Eurythoe complanata (Pallas 1766) has been considered a cosmopolitan species with a great morpholog- ical similarity across its geographic range. To elucidate whether E. complanata is actually a single species, genetic (cytochrome oxidase subunit I and allozymes) and morpho- logical diVerences were compared among specimens from the PaciWc, Caribbean, and South Atlantic Oceans. Large levels of COI divergence (10-22%) and diagnostic allo- zyme loci identiWed three cryptic species: one in the eastern PaciWc and two in the Atlantic, with one being morphologi- cally diVerentiated and found only in islands. COI sequences between PaciWc and Atlantic lineages were much more divergent than those of other transisthmian inverte- brates, indicating their split before the Panama Isthmus closure or a faster evolutionary rate of COI for this species. The existence of two Atlantic species may be a conse- quence of parapatric speciation followed by a secondary invasion or even a sympatric speciation in the Atlantic oce- anic islands.