Diversity and phylogenetic positioning of freshwater lineages of Rhinebotrhium Linton, 1890 (Eucestoda: Rhinebothriidea) from lake Maracaibo and Orinoco basin, Venezuela

Abstract

The study of the phylogenetic relationships is essential to understand biological phenomena from an evolutionary standpoint. Host-parasite systems can be used as biological models for the study of historical associations. Neotropical stingrays and their parasites are an interesting model system because it should reflect the biogeographical history of the host and parasites into the Neotropical freshwater environment. Several authors have devoted efforts to understand the diversification of parasites of stingrays in South America. Rhinebothrium is genus of parasitic cestods of freshwater stingrays. The systematics of this genus was revised in 2011, but the authors of this study had no specimens from the region of Lake Maracaibo and Orinoco, which are essential for understanding the diversification of this group. This study aims to include specimens of these regions in order to obtain a more complete picture of the composition of this genus. Nucleotide sequences of the CO I gene along with morphological cohesion will be used to propose a phylogenetic hypothesis for freshwater lineages of the genus Rhinebothrium. The boundaries between species will be tested using the phylogenetic and morphological congruence with statistical support, provided by the program SPLITS.