Histological and biochemical responses of biomphalaria Alexandrina to tributyltin and the plants dodonaea viscosa and haplophyllum tuberculatum

Tribulyltin and methanol extract of Dodonaea Viscosa and Haplophyllum tuberculatum plants were tested as molluscicidal agents against Biomphalaria alexandrina snails. In addition, the effect of tributyltin and the two tested plants on the survival rate, egg production, the hatchability of eggs and hermaphrodite glands of B. alexandrina snails was carried out. The results indicated that exposure of B. alexandrina to tributyltin and the tested plants led to a significant reduction in their survival rate, egg production and hatchability of their eggs. This was confirmed by histological examination that showed a severe damage in the hermaphrodite gland cells of treated snails. In addition, tributyltin and methanol extract of D. Viscosa and H. tuberculatum had qualitative and quantitative effect on the protein patterns of snail's hermaphrodite gland. The electrophoretic pattern of the native proteins revealed difference in the number and molecular weights of protein bands compared to the control snails. It was concluded that tribulyltin and the tested plants might be helpful in snail control as they interfere with the snail's biology and physiology

Effect of non target snails on some biological of lymnaea natalensis snails and their infection to fasciola gigantica

The influence of non-target freshwater snails [Melanoides tuberculata and planorbis planorbis] on the capacity of Fas-ciola egg production F. gigantica miracidia to infect Lymnaea natalensis and their affect on mortality and growth rates showed that the snails exhibited a competitive ability against L. natalen-sis The mortality rate existed in mixed cultures with snails was greatly increased, and increased with increase of snails number. The egg production and growth rate were negatively affected by the presence of M. tuberculata and p. planorbis which was more pronounced when snails were at higher ratio 1L:10D.Also, the snails showed significant degree of reduction in infection rate of L. natalensis with F.gigantica miracidia.

Effect of water plants and non-target snails on the infectivity of bulinus truncatus with schistosoma haematobium

The application of the water plant [Ceratophyllum demersum, Eichhornia crassipes and Lemna gibba] and/or non-target snails [Planorbis planorbis, Physa acuta and Melanoides tuberculata] gave a significant degree of reduction in the infection rate of B. truncatus subjected to S. haematobium miracidia. The data also indicated a reduction in mean total number of cercarial production/snail. However, no significant difference was detected in the prepatent period and duration of cercarial shedding of the parasite when compared with the control group. So, the results revealed that the snails exhibited a competitive ability against B. truncatus. Both survival rate and egg production of B. truncatus were greatly reduced when existed in mixed cultures with non-target snails and the magnitude of this reduction increased by increasing the number of the non-target snails

Molluscicidal effect of fungicide herbicide and plant extract on some biological and physiological parameters of Biomphalaria alexandrina

It was found that the exposure of B. alexandrina to LC25 of fungicide [Isoprothiolane], herbicide [Anilofos] and plant extract [Euphorbia lactea] led to a highly significantly elevation in the number of abnormal egg masses laid by treated snails in comparison with the control ones. The LC25 caused reduction in infection rate of B. alexandrina. It caused reduction in number of cercariae per snail during the patent period and reduction in the period of cercarial shedding. The results showed that adenosine triphosphatase [ATPase] activity of tissue of snails was significantly increased in response to tested substances. The activity level of lactate dehydrogenase [LDH], pyruvate kinase [PK] and phosphoenolpyruvate carboxy kinase [PEPCK] was significantly reduced in response to the treatment. This reduction did not reflect on both D. lactate and pyruvate concentrations