Sequence divergence of mitochondrial DNA indicates cryptic biodiversity in Octopus vulgaris and supports the taxonomic distinctiveness of Octopus mimus (Cephalopoda: Octopodidae)

• Published in: Marine biology 2000-01, Vol.136 (1), p.29-35
• Main Authors: SÖLLER, R, WARNKE, K, SAINT-PAUL, U, BLOHM, D
• Format: Article
• Language: English
• Subjects: Biodiversity; Biological and medical sciences; Brazil; Caribbean Sea; Coastal waters; Cryptic species; cytochrome oxidase III; Deoxyribonucleic acid; DNA; Ethanol; France; Fundamental and applied biological sciences. Psychology; Haplotypes; Invertebrates; Marine; Marine biology; Mitochondrial DNA; Mollusca; Octopus bimaculatus; Octopus bimaculoides; Octopus californicus; Octopus dofleini; Octopus mimus; Octopus rubescens; Octopus vulgaris; Scaeurgus unicirrhus; Systematics. Geographical distribution
• ISSN: 0025-3162; 1432-1793
• DOI: 10.1007/s002270050004

DNA sequence diversity of octopods was investigated using the mitochondrial cytochrome oxidase III gene (mtCOIII). DNA was obtained from ethanol- or formalin-fixed tissue of 15 specimens belonging to Octopus mimus Gould, 1852, Octopus vulgaris Cuvier, 1797 and Scaeurgus unicirrhus d'Orbigny, 1840, from coastal waters of the Mediterranean (France), the southwestern Atlantic (Brazil), the Caribbean (Costa Rica) and the southeastern/tropical Pacific (north Chile/Costa Rica). A 612 bp fragment of the mtCOIII gene was sequenced and aligned to the orthologous sequences available from northeastern Pacific Octopus species. Possible phylogenetic relationships were reconstructed. The mtCOIII gene tree revealed two main clusters, one comprised O. rubescens, O. dofleini and O. californicus, while the other included all O. vulgaris specimens, O. bimaculatus, O. bimaculoides and O. mimus. With one exception all South American haplotypes including O. bimaculatus and O. bimaculoides appeared as the sister group of the Mediterranean haplotype of O. vulgaris, indicating that most of the South American O. vulgaris specimens investigated would not belong to the recently redescribed species O. vulgaris restricted to the Mediterranean and eastern Atlantic. The treatment of O. mimus as a species distinct from Mediterranean O. vulgaris is supported by a high nucleotide divergence of 12.7%. Based on the mtCOIII gene tree the existence of cryptic species among O. vulgaris-like octopods is suggested.