DEVAERE, S; JANSEN, G; ADRIAENS, D*; WEEKERS, PHH; Ghent University, Belgium; University of Helsinki, Finland; Ghent University, Belgium; Ghent University, Belgium: Clariid catfish: an extreme case of convergent evolution on a low taxonomical level

Clariids represent an impressive range between fusiform and anguilliform morphs. Although this has been observed in other families of teleosts or amphibians and reptiles, it is rarely as extreme as within the Clariidae. Although originally the Clariidae were thought to have undergone an anagenetic evolution, more recent studies provide evidence that supports the hypothesis that anguilliformity evolved several times independently through a process of cladogenesis. Our combined morphological and molecular phylogenetic analyses suggest the derived nature of body elongation. The corresponding morphological changes that co�occur with this elongation, e.g. increase of the number or size of vertebrae, skull length reduction, limblessness, reduction of the eyes, and/or increasing rigidity of the skull, can as such be regarded as an extreme case of convergent evolution at the genus level. Many of these morphological specialisations can be linked to the specialised life style of these anguilliform morphs.