Prevalence and Densities of Contracaecum sp. Larvae in Liza abu (Heckel, 1843) from Different Iraqi Water Bodies

Abstract

In monthly samples of Liza abu collected, June 2001-May 2002 from three localities (Hilla river, Al-Furat fish farm and Al-Mahaweel drain), Babylon province in the middle of Iraq. Fishes were infected with the third larval stage of the nematode Contracaecum sp. The infection of Contracaecum sp. larvae were analyzed according to the season, sex, host length, and sampling localities. Its prevalence and intensity was 11.9% and 1.1 larvae per fish respectively for the Winter, and the Summer had 47.6% and 3.5 larvae per fish respectively. The incidences were increased greatly during the Summer season, being higher in the females than the males for both the seasons of the year. There were slightly significant differences (p < 0.01) between the infection of male and female fishes in the cases of the monthly variations of infection with Contracaecum sp. Infection with Contracaecum sp. larvae were positively correlated according to fish length, increased gradually in the larger fishes. Infection rates and mean intensity also varied with sampling stations (p < 0.05). Generally, the changes in the percentage prevalence coincided with the changes in the mean intensity of infection.

Distribution of Contracaecum (Nematoda: Anisakidae) larvae in freshwater fish from the northern regions of South Africa

“…Boomker (1994a) and Bergmann and Motta (2004) reported that nematode burden increases via ontogenic changes with infection being absent in juveniles but present in adults. Reasons for a greater presence of worms in larger individuals are attributed to a larger body cavity and/or the feeding preference of the second intermediate host (Aloo 1999;Al-Zubaidy 2009). These assumptions are supported by previous studies done on Barbus spp.…”

Parasite infection in Serranus cabrilla (Perciformes, Serranidae): histopathological aspects and new host record for nematode genus Philometra from Aegean Sea, Turkey

“…The fact that both values of prevalence and mean intensity in nematode infections increase with the body length of the host has been noticed before by various authors who suggested that as fish growth, chances of infection are higher either due to the exposure time or the increase of the internal organs of the fish that a parasite can use to attach itself (Moravec and Scholz, 1995;Al-Zubaidy, 2009;Ahmad et al, 2018). Our data are also consistent with some studies that revealed the relation between the sexually mature fish and occurrence of nematodes, younger fish being less infected or even not infected at all than older fish (Bergmann and Motta, 2004;Szostakowska et al, 2005;Perez et al, 2009).…”

Seasonal occurrence of metazoan parasites in Tigerfish, Hydrocynus vittatus Castelnau, 1861 (Characiformes: Alestidae) from Sanyati Basin, Lake Kariba, Zimbabwe

“…Contracaecum sp. is not host-specific in the larval stage (Al-Zubaidy 2009) and the larvae usually occur in the body cavity of the fish (Whitfield & Heeg 1977). They showed a variation in prevalence and reached a peak in winter, but this was not statistically significant.…”