ABSTRACT Population structure of the unionicolid mite _Unionicola anodontae _is polymodal and continued during two years of collection (October 1992 to September 1994). The population was composed of three components. The density of adults (females and males) of the population was recorded monthly, with annual peaks in autumn, winter and summer. Most ecological factors have no clear effect on the ... Read more

ABSTRACT The sex ratio of water mite _Unionicola anodontae_ fluctuated around 50% with biased value to the females. The female reproductive system consists of two different functional parts. The first part is designed for production of ova, formation of egg chorion and releasing of ova and embryos to the exterior. The second part functions in mating, sperm storage and sperm ... Read more

Abstract The parasitic mite _Unionicola anodontae_ is collected from the molluscan host _Anodonta rubens_, described and identified by Ramadan (1995). It displays parental care for its embryos, extended beyond brood protection. This parasite has an asynchronous type of develop­ment. There is no seasonality in reproduction or brooding of embryos. Brooding of embryos is common in the middle classes of the ... Read more

Unlike other assemblages of class Arachnida, many representative groups of the Acari are not predators. Some are exclusively phytophagous, while others include external and internal parasites of both the vertebrates and invertebrates (Krantz, 1970). Molluscans are an interesting group of invertebrates, that are parasitized by a variety of organisms, ranging from viruses to arthropods. Accordingly, a number of pathological changes ... Read more

Adults of four water mite species belonging to genus _Linobia_ Family Linobiidae, Canestrinioidea, Astigmata were collected from the roots of the common floating plant _Eichhornia crassipes_ in the Nile. Three of the four collected species were identified, classified as new species to the genus and named _Linobia nilotica, L.__replacementica_ and _L_. _eichhornia_. The collected species are described in detail and ... Read more