A study on Silver sharks has revealed three new species of gill parasite previously unknown by scientists.
According to a new study by Rehulkova and Gelnar of Masaryk University in the Czech Republic, which is due to be published shortly in the journal Systematic Parasitology, the three new species of Dactylogyrus fluke were found on Balantiocheilos melanopterus imported from aquarium fish suppliers in Thailand.
The new species have been named Dactylogyrus coartatus, D. melanopteri and D. macrocolpius and belong to the Monogenean fluke Order Monopisthocotylea.
Rehulkova and Gelnar claim that the new flukes can be distinguished by their striking morphology: "The double-bar species, D. coartatus n. sp. and D. melanopteri n. sp., are characterised by hooks that are markedly large in relation to the size of the anchors. Clip-like anchors with a sharply recurved, long point are a unique feature of D. coartatus n. sp.
"The single-bar species, D. macrocolpius n. sp., is characterised by having a copulatory organ composed of a spiral copulum and a medial accessory piece with thorns."
Gill flukes of the Dactylogyrus genus irritate the gills and may cause fish to become lethargic, or infected by secondary diseases, such as fungi or bacteria.
The parasites can be difficult, or impossible, to completely eradicate.
For more details on the new parasites see the paper: Rehulkov E, Gelnar M (2006) - Three new species of Dactylogyrus Diesing, 1850 (Monogenea: Dactylogyridae) from the gills of the bala sharkminnow Balantiocheilos melanopterus (Cyprinidae) from Thailand. Systematic Parasitology, 2006, May 5.