Species of Padina (Dictyotales, Phaeophyceae) in tropical Mexican waters based on molecular-assisted taxonomy

Abstract:

Molecular-assisted alpha taxonomy has provided novel ways of exploring biodiversity, and is of great help in taxa where morphology alone is not sufficient to ensure accurate species recognition or delimit species boundaries. Here, we use this approach to assess the taxonomy of Padina Adanson (Dictyotales, Phaeophyceae), a common brown algal genus in Mexican waters. Numerous individuals of Padina from Pacific and Atlantic tropical coasts were analysed using sequences of psbA, cytochrome c oxidase subunit I, and cox3 to determine evolutionary significant units or putative species. Then, cox3 sequences of some individuals of each group were analysed with a large number of sequences available in Genbank using the generalized mixed Yule coalescent and Poisson tree processes models for species delimitation. Each sample was identified using the original and the most common descriptions in the region. Last, the results were evaluated looking for correlations between the molecular and morphological data. We concluded that at least 12 Padina species occurred in Mexican waters, 10 from samples here revised and 2 inferred from Genbank sequences. The study not only revealed the existence of well-identified species, but also the existence of cryptic and polymorphic species, confirming the importance of reassessing type material for proper delimitation and nomenclature. Finally, the evidence supported the independent status of Padina ramonribae Avila-Ortiz, Pedroche & Díaz-Martínez, which is validated here.

Key Words::

• COI
• cox3
• Dictyotales
• GMYC
• Mexican Atlantic coast
• Mexican Pacific coast
• psbA
• PTP
• Species delimitation

ACKNOWLEDGEMENTS

This work was supported by Programa de Apoya a Proyectos de Investigación e Innovación Technológica (PAPIIT) founding IN211505-3 and IN222910 (Universidad Nacional Autonóma de Mexico [UNAM]). The molecular work was done at Molecular Systematics Laboratory (Instituto de Biología, UNAM). We thank Drs. Ángela Catalina Mendoza-González and Luz Elena Mateo-Cid from Escuela Nacional de Ciencias Biológicas (ENCB) for the specimens provided. S.D.-M. benefited from a scholarship during Masters' from the Mexican Consejo Nacional de Ciencia y Tecnología. To Ulices Garcia, Arturo Ubaldo-Fuentes, and Lisandro Hernandez-Anaya for their help taking slide photographs. We thank Editor David Garbary and two anonymous reviewers for the critical comments and corrections.

SUPPLEMENTARY DATA

Supplementary data associated with this article can be found online at http://dx.doi.org/10.2216/16-15.1.s1.