Abstract
The present study was the first investigation of digenetic trematode parasites of
Saurida tumbil
, a commercially important fish species of the Red Sea, during the period from January to December 2011. Thirty-nine out of 103 (37.8 %) of the examined fish were found to harbor the digenetic trematode
Lecithochirium grandiporum
(family: Hemiuridae) infecting the pyloric portion of stomach and middle part of intestines of the lizard fish. The morphology and morphometric characterizations of this digenetic trematode were described by light and scanning electron microscopy. The parasite possessed a body which was elongated and rounded anteriorly, but truncated posteriorly, and its body measured 1.63 ± 0.20 (1.2–1.93) mm (invaginated ecsoma), 2.11 ± 0.20 (1.83–2.35) mm (evaginated ecsoma) in length with a maximum width of 0.4 ± 0.02 (0.31–0.52) mm at ovarian level. They were characterized by a subterminal oral sucker which measured 0.15 ± 0.02 (0.12–0.18) mm in diameter and was smaller than the ventral sucker which was circular and large with a wide aperture, hence the specific name
grandiporum
. A multilobated digitiform vitellarium which was a distinctive feature for this species was also observed. The number of parasite per fish was one to six. Prevalence and intensity of infection were positively correlated with host size (increasing with host size increasing). Host sex does not seem to affect the prevalence of infection. The present study was considered as a first record from the Red Sea in Egypt.