Barraclough R.K. auteur aut IRD Duval L. auteur aut IRD Talman A.M. auteur aut IRD Ariey F. auteur aut IRD Robert Vincent auteur aut IRD text journalArticle eng text/pdf born digital access Understanding the breeding systems of Plasmodium, and the closely related Haemoproteus and Leucocytozoon (Apicomplexa: Haemosporida), is fundamental to virulence and transmission research. We report an unusual binding behaviour between gametocytes of Leucocytozoon toddi. This aggregative behaviour was notably characterised by a disparity in the likelihood of clustering by female and male gametocytes. Thus, indicating a possible difference in the 'stickiness' of gametocytes per sex. Overall, 12% of gametocytes in this high-parasitaemia infection (0.269 gametocytes per 100 red blood cells (RBCs)) were incorporated into aggregations involving substantial contact. The gametocyte sexual combinations within aggregations varied significantly from expected according to the background 0.49 sex ratio within this sample, with female-female contacts occurring more and male-male contacts occurring less frequently than expected. A second L. toddi (identical for 709 bp of the cyt b mitochondrial gene) with lower parasitemia (0.035 gametocytes per 100 RBCs) showed no significant binding. Interestingly, the ratios of male gametocytes in both of these parasites were greater than expected under sex-ratio theory and similar to the 50% observed in species with syzygy breeding strategies. We discuss the ramifications of this observation in terms of sex-ratio theory and breeding strategies and provide speculative explanations for this unusual gametocyte behaviour. specialized 052 102 6 1321-1327 2008 0932-0113 https://www.documentation.ird.fr/hor/fdi:010042563 10.1007/s00436-008-0913-8 0932-0113 [F B010042563] https://www.documentation.ird.fr/hor/fdi:010042563 https://www.documentation.ird.fr/intranet/publi/2008/05/010042563.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2008-05-30 2017-08-23 fdi:010042563 fre