An investigation on fish parasites in Hanna Wetland, Semirom, Isfahan Province

As a part of a major ecological study of Hanna Wetland, Semirum Region, Isfahan
Province, parasitic infestation of 3 native and one introduced fish species were investigated. A
total of 120 fish specimens were collected by both cast net and a series of gillnets between fall
and winter 2007, and spring and summer 2008. Some of the observed parasites are reported
for the first time as new host records of: Trichodina perforata on gill and skin of Carassius
auratus auratus and three species of leeches namely: Glossiphonia heteroclite, Thromyzon
tessulatum and Hemiclepsis marginata on the skin and fin bases of Capoeta damascina.
Moreover, 14 internal and external parasites including: one protozoan Ichthyophthirius
multifiliis and two myxosporeans Myxobolus varicorhini, Myxobolus sp., three monogeneans
Dactylogyrus lenkoran, Dactylogyrus intermedius and Gyrodactylus sp., two immature
digeneans Diplostomum spathaceum, Tylodephys sp., two mature digeneans Allocreadium
isoporum and A. layman, one unknown cyst, one Acanthocephalan
Acanthocephalorhynchoides sp., one cestoda Khawia armeniaca. The highest prevalence of
Diplostomum spathaceum (100%) was observed in Aphanius isfahanensis and Alburnus sp.
However, the lowest prevalence was related to A. layman in Capoeta damascina in winter
(0%), and autumn and spring (11%). Leeches infection were only observed in Capoeta
damascina and Alburnus sp. in winter and summer, respectively. The maximum average
(±SD) infection intensity belonged to K. armeniaca in intestine of C. damascina in spring
(12.50±3.40, range: 8-16). Among the parasites identified in the region, D. spathaceum
showed the highest mean (±SD) abundance (41.67±11.79) in C. auratus auratus in spring. In
general, a relatively high diversity of fish parasitic fauna exists in this water body which could
jeopardize fish populations and the whole ecosystem if the ecological status of the Hanna
Wetland is neglected.