THE OCCURRENCE OF LARVAL DIGENEA IN SOME SNAILS IN KUWAIT BAY

Between February and March 1986, 18 species of snails were collected from different habitats in Kuwait Bay; 2.9 % were infected. A total of 16 species of cercariae were recovered representing the following morphological types: brevifurcate-apharyngeate (1), cotylomicrocercous (2), furcocystocercous (2), gymnocephalous (1), longifurcate-pharyngeate (1), megalurous (3), oculate trichocercous (1), parapleurolophocercous (1), and xiphidiocercaria (4). Of the mature cercarial infections, 19.5 % were furcocystocercous cercariae infecting Clypeomorus bifasciatus, followed by xiphidiocercaria (10.1 %) in 4 host species. Snails harboring immature infections were encountered 142 times, mainly in the limpet Siphonaria rosea, and accounted for 52.8 % of all infections. Metacercarial infection was found only in Planaxis sulcatus (1.11 %). The larger variety of cerariae were recovered from the mud snail Cerithidea cingulata which contributed 6 of the species encountered. Snails from muddy and sandy habitats had higher infection rates and diversity of cercarial types than those from rocky habitats. This is possibly due to differences in the abundance of birds and fish definitive hosts in the two habitats.