Water mites of the genus Unionicola are the most common symbionts of freshwater bivalves. During the current investigation, a total of 120 live freshwater mussels representing 5 species, Corbicula fluminea (Veneroida), Coelatura aegyptiaca (Unionoidea), Mutela rostrata, and Chambardia rubens (Mutelidae), were collected from 2 localities in Tura (Helwan Governorate) and El Kanater (Qaluobiya Governorate), Egypt. Only 3 of the 4 bivalve species listed are considered freshwater bivalves (members of Unionoidea). Corbicula fluminea belong to the family Cyrenidae within Veneroida. Collected mussels were dissected and examined for the presence of unionicolid mites. It was found that 30.83% (37/120) were infected with a single mite species, Unionicola tetrafurcatus (Unionicolidae). The highest prevalence was observed during the summer with 83.33% (25/30) whereas the least was observed in autumn, i.e., 33.33% (10/30). Mites were recovered from the gills, gonads, and visceral mass of mussel hosts. Gills of host mussels were the primary site of oviposition for Unionicola mites. Smaller bivalves in size had significantly greater numbers of mites than did larger ones in size. Numbers of mites per host species was variable and the highest prevalence level of 83.33% (25/30) was recorded in Cor. fluminea while the lowest one of 16.66% (5/30) was found in Ch. rubens. Morphological and morphometric characterizations of mites revealed some differences between the present species and other related Unionicola. Histopathological responses of host mussels to the eggs, larvae, and cuticular remnants of U. tetrafurcatus were also studied. Therefore, the present study demonstrated that freshwater bivalves have a new host and locality records for infection with U. tetrafurcatus. Future studies are recommended to include advanced molecular characteristics for these mites.

In the present study, A cestode parasite was recovered from the intestine of the domestic sheep, Ovis aries (Bovidae) from the main slaughterhouse of Cairo, Egypt during the year of 2015. The parasite was observed attached to the wall of the host intestine by unarmed scolex with suckers only. Five out of 10 gastrointestinal tracts (50%) were found to be infected. Light microscopic examination showed that the adult worm of this species was whitish in color measured 421-492 (470±0.4) cm in length and 4.2-6.99 (5.6±0.7) mm in width. The scolex was with prominent four suckers measured 0.38-0.42mm in diameter. The scolex led into a long neck followed by segments. The mature segment was broader than longer, each proglottid measured 3.23-5.29 (4.6± 0.2) mm in width and 1.0-1.64 (1.4±0.02) mm in width and showed a two set of genital organs. The ovaries and the vitelline glands formed a ring on either side, median to the longitudinal excretory canals, while the testes were distributed throughout the central field or they may be concentrated toward the sides. Each ovary was of ovoid shape, measured about 0.16-0.19 (0.14±0.01) × 0.12-0.15 (0.13±0.02) mm and was located 0.8± 0.1 mm apart from the lateral side. The testes were concentrated on both sides. At the posterior border of each proglottid, a row of interproglotidal glands was arranged around small pits. Gravid segments measured 0.022-0.076 (0.048±0.2) mm in length and 2.10-5.02 (3.05±0.02) mm in width. The present parasite was compared with the previous species of the same host which showed that the parasite isolated is Monezia expansa.

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Background Schistosomiasis is a major, but generally overlooked, tropical disease carried by snails of the genus Biomphalaria, which have a large distribution in Egypt. Control of the intermediate host snail is critical in limiting schistosomiasis spread. On the topic of snails’ management, nanotechnology has gained more interest. Results Copper oxide nanoparticles, characterised by transmission electron microscopy and X-ray diffraction, showed a single crystal structure with an average crystallite size around 40 nm by X-ray diffraction and typical transmission electron microscopy (TEM) image. Also, the UV–VIS spectrophotometer displayed a sharp absorption band of CuO NPs. Molluscicidal activity of copper oxide nanoparticles against B. alexandrina snails was observed. Following exposure to CuO NPs (LC50 and LC90 was 40 and 64.3 mg/l, respectively), there was a reduction in the growth and reproductive rates of treated B. alexandrina at the sub-lethal concentrations, as well as, a drop in egg viability. Moreover, CuO NPs exhibited a toxic effect on miracidiae and cercariae of S. mansoni. Scanning electron microscopy (SEM) investigations of the head-foot and mantle of control and treated snails to the sub-lethal concentrations of CuO NPs (LC10 15.6 mg\l–LC25 27.18 mg\l) indicated morphological alterations in the ultrastructure. Conclusions CuO NPs caused a significant effect against the intermediate hosts of S. mansoni and provide a considerable scope in exploiting local indigenous resources as snail molluscicidal agents.

Background Land snails, especially the chocolate banded snails, Eobania vermiculata (Muller 1774) are destructive pests of a wide range of field and vegetable crops, and biological treatment appears to be better alternative to the chemical snail control. Therefore, the goal of this work was to assess the molluscicidal activity of chitosan extracted from the crawfish Procambarus clarkii against E. vermiculata using oxidative stress, histopathological and genotoxic biomarkers. Results Exposure of snails to LC50 (222.4 mg/l) chitosan for 1, 3 and 7 days induced a significant increase in glutathione S-transferase and catalase levels then decline in reduced glutathione content after 1 and 3 days as well as a slight decrease in CAT levels, GSH content and GST of the treated snails after 7 days exposure. Histologically, the stress induced by chitosan exposure leads to deformation of cells, dilatation of the intertubular spaces, and destruction of tubules with increase in lumen size, necrosis of digestive cells with rise in vacuoles number and increase in calcium cells number. Considerably, a great damage was observed with increasing time of exposure. Furthermore, genotoxicity was assessed using RAPD-PCR technique and the results revealed that change in RAPD profiles of E. vermiculata following chitosan treatment included loss of normal DNA bands and appearance of new one compared to control snails. The genomic template stability was 63.6, 36.4 and 18.2% 1, 3 and 7 days of exposure, respectively. The apparent of new bands increased as time of exposure decreased, while GTS values decreased confirming the effect of chitosan-induced DNA damage. Conclusion Chitosan may be an ecofriendly acceptable alternative pesticide for snail control.