Lankesterella, a neglected avian blood parasite: phylogeny, host specificity, prevalence and its influencing factors

• Autores: Ashwin Kumar Saravana Bhavan Venkatachalam
• Directores de la Tesis: Milena Svobodová (dir. tes.)
• Lectura: En la Univerzita Karlovy v Praze = Charles University of Prague ( Chequia ) en 2025
• Idioma: inglés
• Número de páginas: 63
• Tribunal Calificador de la Tesis: Rodrigo Manuel Megía Palma (voc.), Alzbeta Sujanová (voc.), Jan Votýpka (voc.), Ivan Čepička (voc.)
• Enlaces
  • Tesis en acceso abierto en: dspace.cuni.cz
• Resumen

  • Blood parasites in songbirds are common and frequently studied, with one notable example being Lankesterella, a common but understudied genus of blood coccidians. The genus is known to commonly occur among reptiles and amphibians, but recent studies focus on infections among birds as well. This thesis summarises the results obtained while focusing on three main objectives: investigating avian Lankesterella phylogeny, host specificity, prevalence and the factors influencing it across multiple avian species, particularly in the families Paridae (Parus major, Cyanistes caeruleus, Poecile palustris) and Acrocephalidae (Acrocephalus schoenobaenus, A. palustris, A. scirpaceus), whose blood parasites are readily used as models for studying host-parasite interactions. The first study focused on the phylogeny of Lankesterella based on the molecular analysis of 18S rDNA gene from blood samples and revealed that the genus Lankesterella is monophyletic and the sequences obtained from amphibians, reptiles and birds form their own distinct clades and exhibit strong host specificity, often at the genus or species level. The second study focused on determining the prevalence of Lankesterella and the factors influencing it in passerine hosts. Prevalence varied significantly by study site, host species, age, and sex, with chronic infections driven by host age and sex. The third study focused on the differences in host specificity among Lankesterella and Isospora in avian species. A total of 36 Lankesterella and 33 Isospora haplotypes were identified. Isospora exhibited a different pattern of host specificity compared to avian Lankesterella, with identical sequences found in both blood and fecal samples of warblers and hawfinches. These findings significantly advance our understanding of Lankesterella phylogeny and the ecological factors shaping its prevalence, host specificity, and diversity. This thesis underscores the value of molecular tools in revealing these patterns across passerine hosts.