Host age and the growth and fecundity of Hymenolepis diminuta in the rat.
Five, 20, and 80 cysticercoid infections of Hymenolepis diminuta were established in 1-, 2- and 5-month-old male Wistar rats. Worm numbers, dry weights and egg outputs were determined on day 28 post infection. Worm recovery was found to be independent of cysticercoid dose in 1-month-old rats, but density-dependent in older rats. Density dependence affected both worm dry weight and egg production in all 3 age classes of host studied. However, at the highest dose both dry weight and egg production were significantly decreased in 2- and 5-month-old rats compared with 1-month-old rats. The results cannot be explained solely in terms of competition for a resource, and suggest that immunological mechanisms may have an important role in the "crowding effect".
Quinnell
R J
RJ
Department of Parasitology, Molteno Institute, Cambridge, UK.
D000375:Aging / Q000276:immunology*; D000818:Animals; D004040:Dietary Carbohydrates / Q000494:pharmacology; D006790:Host-Parasite Interactions; D006925:Hymenolepiasis / Q000469:parasitology*; D006926:Hymenolepis / Q000254:growth & development*; D007422:Intestines / Q000469:parasitology; D008297:Male; D010270:Parasite Egg Count; D011156:Population Density; D051381:Rats; D011919:Rats, Inbred Strains
D004040:Dietary Carbohydrates