Infection patterns of Nile tilapia (Oreochromis niloticus L.) by two helminth species with contrasting life styles
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Date
2012
Journal Title
Journal ISSN
Volume Title
Publisher
Parasitology research
Abstract
The larval stages of Bolbophorus sp. (digenean)
and Amirthalingamia macracantha (cestode) are frequently
reported in Oreochromis niloticus in Uganda. Little,
however, is known about their infection patterns. This
study examined the influence of habitat type, host size, and
sex and weather patterns on the parasite populations in
Uganda. A total of 650 fish were collected between January
and November 2008 from a reservoir, cages, fishponds and
a stream. The prevalence and intensity of A. macracantha
and the prevalence of Bolbophorus sp. differed across the
water bodies reflecting the effect of habitat characteristics
on parasite transmission. Host sex did not significantly
influence the infection patterns, although female fish were
slightly more parasitized than male and sexually undifferentiated
individuals. The fish size was positively correlated
with helminth infections demonstrating accumulation and
prolonged exposure of larger (older) fish to the parasites.
The metacercariae population did not vary significantly
across months, while monthly A. macracantha infection
fluctuated markedly. With regard to rain seasons, higher
prevalence and intensity of A. macracantha were recorded
in wet season. For Bolbophorus sp., only the prevalence
varied with seasons, with higher prevalence recorded in the
dry season than in wet season. Generally, Bolbophorus sp.
responded weakly to changes in water body, host sex and
size and weather patterns. Rainfall appears to be an
essential cue for coracidia hatching.
Description
Keywords
Infection patterns, Nile tilapia (Oreochromis niloticus L.), Helminth species, Life styles
Citation
Akoll, P., Konecny, R., Mwanja, W. W., & Schiemer, F. (2012). Infection patterns of Nile tilapia (Oreochromis niloticus L.) by two helminth species with contrasting life styles. Parasitology research, 110(4), 1461-1472. DOI 10.1007/s00436-011-2649-0