Publication details

ULTRASTRUCTURAL OBSERVATIONS ON REPRESENTATIVES FROM FAMILY DIPLOZOIDAE (MONOGENEA)

Authors

KONSTANZOVÁ Veronika KOUBKOVÁ Božena GELNAR Milan

Year of publication 2017
Type Conference abstract
MU Faculty or unit

Faculty of Science

Citation
Description Diplozoons are blood-feeding ectoparasites with specific life-cycle, parasitizing mainly on gills of cyprinid fish, where they can cause mechanical damage to the gill filaments, initiating the development of secondary infections (bacterial, mycotic) and anemia. During the diplozoon life cycle two larvae, the diporpae, pair and subsequently fuse permanently producing the typical X-shaped diplozoon body arrangement, this is a unique character for Diplozoidae. Although these worms have been the subject of numerous taxonomical, phylogenetic, and ecological studies, the detailed studies of their inner systems have remained relatively neglected. This presentation is based in comprehensive study focusing on diplozoids morphology and ultrastructure, looking for phylogenetic and functional indicators of their specific life strategy. The samples of several diplozoon species were collected from the gills of different species of host fish D. paradoxum (A. brama), E. nipponicum (C. carpio), P. homoion (A. alburnus) and P. bliccae (B. bjoerkna), which were caught in the littoral zone of the Mušov lowland reservoir. The fish gills were extracted and checked for the presence of all diplozoid ontogenetic stages. Parasites intended for transmission electron microscopy (TEM) were washed in freshwater to remove any remaining mucus and then fixed in 2% osmium tetroxide and dehydrated through an ascending acetone series. The dehydrated samples were embedded in Spurr resin. In order to obtain a better orientation in basic diplozoon morphology several semi-thin sections (0.5 µm) of whole worm bodies were cut using a Leica EM UC6i. Sections were stained with toluidine blue. Ultrathin sections were contrasted with uranyl acetate, followed by citrate, and examined using a JEOL JEM-1010 TEM. The presentation focusses on the morphological and ultrastructural features of different body structures such as neodermal surface, gastrointestinal tract, excretory system and attachment clamps.
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