Folia Parasitologica 69:022 (2022) | DOI: 10.14411/fp.2022.022

Comparative exploration of the morphological plasticity of Trichodina centrostrigeata (Peritrichia: Mobilida), ectoparasite from the gills of two tilapia species (Oreochromis niloticus and O. mossambicus) in a global context

Alma Gabriela Islas-Ortega ORCID...^{1, 2}, Paula S. Marcotegui ORCID...³, Linda Basson ORCID...⁴, Gerhard P. de Jager ORCID...⁴, Rogelio Aguilar-Aguilar ORCID...¹

¹ Departamento de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México, México, D.F., Mexico;

² Posgrado en Ciencias Biológicas, Facultad de Ciencias, Universidad Nacional Autónoma de México, México, D.F., Mexico;

³ Instituto de Investigaciones Marinas y Costeras, Mar del Plata, Argentina;

⁴ Department of Zoology and Entomology, University of the Free State, Bloemfontein, South Africa

Trichodina centrostrigeata Basson, Van As et Paperna, 1983 from Oreochromis mossambicus (Peters) and O. niloticus (Linnaeus) from different host populations from Argentina, Mexico and South Africa was reviewed. Although T. centrostrigeata has a distinct denticle structure that makes morphological taxonomic inferences uncomplicated, variation of the denticles within and among individuals and populations were still observed. While traditional taxonomy of mobilines is heavily reliant on morphometrics, and recently even more so on molecular analysis, this paper proposes the use of geometric morphometry, specifically elliptical Fourier analysis, to address morphological conflicts that arise when comparing different populations. By applying this technique, combined with traditional taxonomy, it was found that T. centrostrigeata in this study can be grouped into two separate morphotypes, the first (type a) from aquaculture farms in Argentina and Mexico and the second (type b) from a natural habitat in Glen Alpine Dam, South Africa. This study supports the validity of geometric morphometry as an additional technique to distinguish not only between species but also evolutionary plasticity of the same species from different localities and habitats.

Keywords: Ciliates, geometric morphometry, Fourier analysis, Trichodinidae, morphology

Received: November 23, 2021; Revised: June 6, 2022; Accepted: July 4, 2022; Published online: October 13, 2022  Show citation