Bat-Sheva Shevy Rothman | Israel Taxonomy Initiative

The phylogeny of Monogenea (Platyhelminth) fish parasites

The Monogenea is one of the largest classes of parasitic flatworms (Platyhelminthes) with between 3,000 to 4,000 described species, inhabiting marine, brackish and freshwater environments. The number of species is estimated to be at least 25,000, similar to the number of teleost species. Monogenea have a direct life cycle and a high degree of host and site specificity: the vast majority of species is ectoparasitic on the gills, skin, fins, nostrils and oral cavity of freshwater or marine fish. Cases of large scale mortalities, due to monogenean infestations, were documented particularly, but not exclusively, in cultured fish. Accordingly, the economic importance of the group is considerable.
Monogenean diversity of the Mediterranean coast of Israel is poorly studied. Considering the high number of alien fish species in our region it may be assumed that some of them would be accompanied with monogeneans. However, just a few records of monogenean invasions are known.
The identification and description of Monogenea is ordinarily based on morphological differences. Molecular and morphological methods are applied on both the parasite and its host to study cospeciation and coevolutionary interactions.
This study will aim: (1) to use morphological and molecular means to classify monogenean species infecting fish species along the Mediterranean coast of Israel; (2) to investigate host-parasite coevolution by reconstructing phylogenies for monogeneans, and respectively compare them to the phylogenetic tree of their fish hosts; (3) to compare the monogeneans species found on alien fish hosts in both new and native populations.