Fatty acid composition of Biomphalaria glabrata (Gastropoda: planorbidae) experimentally infected with the intramolluscan stages of Echinostoma caproni (Trematoda)

Effects of Nonschistosome Larval Trematodes on Biomphalaria Snails

“…Various chromatography techniques (thin-layer and gas-liquid chromatographies) have been used to study the effects of E. caproni infection on different biochemical components of the digestive gland-gonad complex of B. glabrata, and the results are different depending on the biological substance studied. Fried et al ( , 1993 and Shetty et al (1992) noted significant reduction in the concentration of various lipids, and Perez et al (1994) and Wagner et al (2001) reported similar reductions in several carbohydrates. However, Perez et al (1995) showed significant phospholipid elevation in infected snails and Beers et al (1995) observed that the digestive gland-gonad of infected snails maintained on a yolk diet showed a significant increase in free sterols and a significant decrease in triacylglycerols compared with uninfected snails maintained on a lettuce-Tetramin diet.…”

The role of trematode parasites as a nutritional food source for higher trophic level consumers

“…Infected body tissue had the highest mass fraction of 22:6n-3 (DHA) than infected foot, uninfected body and uninfected head/foot. The observed increase in the lipid content of infected hosts suggests that trematode infections have patho-biochemical effects on the lipid composition of their hosts or are perhaps driven by lipid secretions from the parasites (Southgate 1970;Lunetta and Vernberg 1971;Fried et al 1993a, b;Fried et al 1998c). The role(s) of lipids in larval trematode parasites (rediae and cercariae) are still somewhat speculative, and therefore further investigations into the mechanisms and role of lipids in the parasite-host relationship, as well as within parasites themselves, are required.…”

“…Consequently, cercariae derive all of their nutrients, from their snail hosts, during the rediae or sporocyst stage ). The presence of these infections within gastropods induces patho-biochemical changes in the composition of host tissue and hemolymph; however, the effects of trematode infection on snail lipid composition have been contradictory (Fried et al 1989(Fried et al , 1993a(Fried et al ,b, 1998. Among these changes are parasite-induced alterations to the lipid composition of the snail host (Fried et al 1989(Fried et al , 2001.…”

“…However, as noted above, the results have varied based on snail and infection type, with reports of both increased and decreased levels of the triacylglycerol fractions (TAG) in the snails. Fried et al (1989Fried et al ( , 1993a, Shetty et al (1992) and Bandstra (2006) reported significant reductions in the TAG fraction of the digestive gland-gonad (DGG) complex (the snail tissue structure in which rediae and sporocysts develop), while others have reported significant increases in the TAG fraction (Thompson 1987;Fried et al 1998c;). These differences indicate that trematode infections markedly influence the lipid composition of snail bodies but are likely dependent on the species involved .…”

Studies of echinostomes using chromatography and atomic spectrometry.

“…Both populations contained the phytosterols desmosterol, campesterol, stigmasterol, and beta-sitosterol, but the percentage composition was reduced in the infected snails. Fried et al (1993a) did GLC studies to determine the fatty acid composition of B. glabrata snails experimentally infected with the intramolluskan stages of E. caproni . The infection was found to reduce the amounts of saturated fatty acids in whole snail bodies, but increased the amounts of these acids in the DGG complex of the snails.…”