Lipid synthesis is an important process in most organisms, including helminths. Current observations include the cestode, Raillietina (Fuhrmannetta) echinobothrida; nematode, Ascaridia galli and their host, the common country fowl, Gallus domesticus. Total lipids (TL), neutral lipids (NL), glycolipids (GL), phospholipids (PL) and their cestodes, nematodes and fatty acids of liver and intestinal fluids were analyzed by thin layer chromatography and gas liquid chromatography, respectively. The results show that the liver takes up more TL, PL, and GL except for NL. Comparison of gut fluid lipid consumption among parasites revealed that cestodes had higher TL and PL content than nematodes, while nematodes absorbed more NL and GL than cestodes. The percentage of cholesterol in cestodes is higher than in nematodes. Palmitic, stearic, oleic, and linoleic were the predominant fatty acids among all samples. This study suggests that large-surface cestodes are more opportunistic in resource utilization than nematodes and hosts.
Key words: Cestodes, Nematodes, Total lipids, Neutral lipids, Glycolipids, Phospholipids, TLC, GLC, Cholesterol
The metabolic dependence of parasites makes interactions with their hosts inevitable, and the study of host-parasite interactions can be considered an important topic (Bush et al. 2001). Parasites are now interpreted as engaging in an exploitative trophic interaction with their host, in which the latter is somehow disadvantaged or harmed. This is what Dawkins (1986) calls an evolutionary “arms race”. Parasites obtain their nutritional requirements directly from stored nutrients (Cheng 1986) or from ingested or partially digested food material by the host. The nutritional relationship of organisms has given rise to animal associations. Parasite–parasite competition for food may be a major selection pressure driving host–parasite associations. A parasite’s dependence on food is not important unless it can use the food it obtains.