Vignon M. auteur aut IRD Pariselle Antoine auteur aut IRD Vanhove M. P. M. auteur aut IRD text journalArticle eng text/pdf born digital access Cichlidogyrus spp. (Monogenea, Ancyrocephalidae) are common parasites of cichlid fishes from Africa and the Levant. They display important morphological variation in their attachment apparatus and infect a broad host spectrum throughout a wide geographic range. Thus, they offer an interesting model to investigate to what extent the phenotypic variability of the attachment organ among congeners is related to host specificity, geographic/environmental components, or phylogeny. A geometric morphometric approach was carried out to analyse the shape variation of sclerotized structures of the attachment organ within 66 African species of the genus Cichlidogyrus. The interspecific shape comparison supports the presence of three main morphological configurations, each consisting of a given combination of particular sclerite shapes. Moreover, data emphasize strong coordination and integration (shape co-variation) among the different sclerites jointly forming the attachment organ. Although attachment apparatuses are usually considered to be the result of adaptive processes and must be adapted to the hosts and local environmental conditions, we found no relationship between these clusters and host specificity or geographical distribution. Nevertheless, groups are partially congruent with those obtained with the molecular phylogeny of a subset of species, suggesting a phylogenetic constraint rather than an adaptation to either hosts or environment. Because of the necessity to form a functional entity, modularity within attachment organ imposes important evolutionary constraint. This provides new insights into the evolvability of attachment organs, as well as into the morphological basis of host specificity and host-parasite co-evolutionary interaction in helminth parasites. specialized adaptation - biogeography - Cichlidae - constraints - evolution - geometric morphometrics - haptor - parasite 034 080 102 3 694-706 2011 0024-4066 https://www.documentation.ird.fr/hor/fdi:010053131 10.1111/j.1095-8312.2010.01607.x 0024-4066 [F B010053131] https://www.documentation.ird.fr/hor/fdi:010053131 https://www.documentation.ird.fr/intranet/publi/2011/03/010053131.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2011-04-07 2017-08-23 fdi:010053131 fre