Contributions to the taxonomy, zoogeography and phylogeny of Laophonte philippi, 1840 (Copepoda, Harpacticoida, Laophontidae)

Laophonte cornuta which is the type species of the genus Laophonte was redescribed based on female neotype that was newly collected from the terra typica in Italy in order to stabilise the taxonomy of the species. On the other hand, the morphological examination of the cornuta material collected from localities far from the Mediterranean Sea has clearly demonstrated that the previously established limit of variation within the species in the existing literature is not correct and L. cornuta populations reported from other parts of the world represent different species and therefore 12 species new to the science have been proposed. A comprehensive phylogenetic analysis was carried out to test the monophyletic status of the genus Laophonte. For this purpose, 46 morphological characters of 118 species belonging to 74 genera of the family Laophontidae were evaluated by using parsimony approach and all results unambiguously revealed that the genus is not monophyletic but polyphyletic. In addition, 18S rDNA sequences of four species (L. cornuta, L. sp12, Heterolaophonte sp. and Paralaophonte sp.) and COI sequences of two species (L. cornuta ve L. sp12) were obtained. These data combined with 18S rDNA and COI data for Laophontidae obtained from NCBI GenBank were used to construct maxsimum likelihood tree which also supported the polyphyletic status of the genus Laophonte. On the other hand, the monophyly of cornuta group of 19 species was supported in all phylogenetic analysis and therefore it has been proposed that the genus Laophonte must be restricted to L. cornuta group of 19 species. A new diagnosis for the genus was provided and all other species assigned to the genus Laophonte were placed as incertae sedis in Laophontidae. The developmental stages of Laophonte sp12 was described based on cultured material for the first time in order to contribute to the taxonomy of the genus. Detailed descriptions, drawings, and confocal images of all six nauplii and six copepodite stages were presented. It has been shown that the sexual dimorphism is first appeared at the copepodid IV stage. The distribution of supposed cosmopolitan species L. cornuta was re-evaluated on the basis of examined material and reliable published records. The known distribution of all Laophonte species were summarised.