Population genetic theory predicts that in small populations, random genetic drift will fix and accumulate slightly deleterious mutations, resulting in reduced reproductive output. This genetic load due to random drift (i.e., drift load) can increase the extinction risk of small populations. We studied the relationship between genetic variability (indicator of past population size) and reproduc...

To estimate isotopic changes caused by trematode parasites within a host, we investigated changes in the carbon and nitrogen isotope ratios of the freshwater snail Lymnaea stagnalis infected by trematode larvae. We measured carbon and nitrogen stable isotopes within the foot, gonad, and hepatopancreas of both infected and uninfected snails. There was no significant difference in the delta13C an...

A comparative assessment of physiological and cygotenetical parameters in Lymnaea stagnalis populations from Perstok lake and the inlet of Pripyat river with the highest in Belarus and moderate levels of radioactive contamination have been carried out. In 2004 f γ-activity of snails from river and lake amounted to 39.2 and 567.8 Bq kg, respectively, and β-activity – to 123.4 and 7055 Bq kg resp...

The phospholipid and protein compositions of mitochondrial membranes from hepatopancreas of active and estivating terrestrial snails ( Cepaea nemoralis) were compared. Mitochondria from estivating snails contained 82.7% less cardiolipin, and this was associated with an 83.9% reduction in cytochrome- c oxidase activity. Substantial changes also occurred in the proportional amounts of other indiv...

Natural infections of Galba truncatula with Haplometra cylindracea were followed from 2001 to 2009 to determine if their characteristics were similar when snails came from water collections frequented by Bufo bufo or by frogs and newts for their egg-laying. Snail samples were collected from both types of sites to count shed cercariae for three days and also free cercariae when snails were disse...

The California horn snail, Cerithideopsis californica, and the shore crabs, Pachygrapsus crassipes and Hemigrapsus oregonensis, compete for epibenthic microalgae, but the crabs also eat snails. Such intraguild predation is common in nature, despite models predicting instability. Using a series of manipulations and field surveys, we examined intraguild predation from several angles, including th...

OBJECTIVE To detect the species of larval trematodes (cercariae) in Melanopsis praemorsa snails from 5 different fresh water bodies in Palestine. METHODS A total of 1 880 Melanopsis praemorsa snails were collected from different fresh water bodies in Palestine from October, 2008 to November, 2010. Cercariae in Melanopsis praemorsa snails were obtained by lighting and crushing methods. The beh...

Experimental infections of Galba truncatula (two populations) with Fasciola hepatica or Paramphistomum daubneyi were carried out to study the effect of water temperature changes (3 h at a mean of 12 °C every week) on cercarial shedding during the patent period. The results were compared with those of control snails infected according to the same protocol and always maintained at 20 °C. Compared...

BACKGROUND Trematodes belonging to the genus Schistosoma cause schistosomiasis. The relationship between schistosomes and their intermediate hosts varies among snails. This study investigated the effects of S. japonicum on its snail host, Oncomelania hupensis, and cercarial release rythmicity of S. japonicum and the effects of light on it. METHODS Seven groups of O. hupensis (n = 40 each) wer...

The pond snail Lymnaea learns conditioned taste aversion (CTA) and remembers not to respond to food substances that initially cause a feeding response. The possible relationship between how well snails learn to follow taste-aversion training and brain dopamine contents is not known. We examined this relationship and found the following: first, snails in the act of eating just before the commenc...