Parasitic infections of some freshwater ornamental fishes imported in Pakistan

This study was designed to investigate the parasitic infection in five species of freshwater ornamental fishes imported to pakistan. a total of 178 fishes; goldfish,carassius auratus l.; guppy,poecilia reticulata (peters); molly,poecilia sphenops (valemiemmes); platy,xiphophorus maculatus (gunther) and swordtail,xiphophorus helleri (heckel) were examined for parasitic infection. three monogenean species (gyrodactylus turnbulli harris 1986;,gyrodactylus vonnordmann,dactylogyrus extensus mueller and van cleave 1932); six protozoans (trichodina ehrenberg 1831,chilodonella stand,1928,ichthyophthirius multifiliis fouquet,1876,piscinoodinium pillulare schaperclaus 1954,tetrahymena sp.,epistylis ehrenberg,1830.); one digenean (metacercaria of cryptocotyle lube,1899.) and two copepod arthropods (lernaea cyprinacea l. and argulus foliaceus muller,1785) were recorded from these fishes. the overall parasitic infection in these fishes was 69.10%. the infection and mean intensity in these fishes were; goldfish (75%,31.24),molly (52%,24.69),platy (66.66%,22.25),swordtail (56.52%,17.4) and guppy (75%,15.86). monogenean and protozoan were recorded from each fish species. clinically the infected fishes were week,lethargic,with whitish to yellowish cysts on the skin. the scales were eroded and haemorrhages were present at the base of fins. the gills were damaged with hyperplasia on secondary lamellae. monogenean parasitic load on goldfish was higher (p < 0.01) than other fish species. the intensity of metacercaria of cryptocotyle sp. was higher (p < 0.05) in platy. the introduction of transmissible parasites through the import of ornamental fishes may cause serious disease problems in native fish species,which may have negative impact on emerging ornamental fish trade in pakistan. copyright © 2014 zoological society of pakistan.