From commensalism to parasitism in Carapidae (Ophidiiformes): heterochronic modes of development?

PeerJ

article

Eric Parmentier¹  Déborah Lanterbecq²  Igor Eeckhaut² 

[1] Laboratory of Functional & Evolutionary Morphology, AFFISH-RC, University of Liège;Biology of Marine Organisms and Biomimetics, University of Mons;Laboratoire de Biotechnologie et Biologie Appliquée, Haute Ecole Provinciale de Hainaut-Condorcet

关键词: Molecular phylogeny;    Character evolution;    Symbiosis;    Pearlfish;    Echinoderms;    Carapus;    Encheliophis;    Sound production;    Ontogeny;   

DOI  :  10.7717/peerj.1786

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Phenotypic variations allow a lineage to move into new regions of the adaptive landscape. The purpose of this study is to analyse the life history of the pearlfishes (Carapinae) in a phylogenetic framework and particularly to highlight the evolution of parasite and commensal ways of life. Furthermore, we investigate the skull anatomy of parasites and commensals and discuss the developmental process that would explain the passage from one form to the other. The genus Carapus forms a paraphyletic grouping in contrast to the genus Encheliophis, which forms a monophyletic cluster. The combination of phylogenetic, morphologic and ontogenetic data clearly indicates that parasitic species derive from commensal species and do not constitute an iterative evolution from free-living forms. Although the head morphology of Carapus species differs completely from Encheliophis, C. homei is the sister group of the parasites. Interestingly, morphological characteristics allowing the establishment of the relation between Carapus homei and Encheliophis spp. concern the sound-producing mechanism, which can explain the diversification of the taxon but not the acquisition of the parasite morphotype. Carapus homei already has the sound-producing mechanism typically found in the parasite form but still has a commensal way of life and the corresponding head structure. Moreover, comparisons between the larval and adult Carapini highlight that the adult morphotype “Encheliophis” is obtained by going beyond the adult stage reached by Carapus. The entrance into the new adaptive landscape could have been realised by at least two processes: paedomorphosis and allometric repatterning.

【 授权许可】

CC BY