Main Content

The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Ref ID : 3574

Krzysztof Wiackowski and Malgorzata Szkarlat; Effects of food availability on predator-induced morphological defence in the ciliate Euplotes octocarinatus (Protista). Hydrobiologia 321:47-52, 1996

Reprint

In File

Notes

The effect of a prey's food resource on predator-induced morphological transformation was studied in two ciliate species: Euplotes octocarinatus (prey) and Stylonychia mytilus (predator). The ability to produce defence in Euplotes was much reduced by the prolonged starvation. The extent of prey morphological transformation and therefore the effectiveness of the defence was inversely related to the length of time without food. The results suggests that the defence involves an energetic cost which may be a significant part of the whole cell budget, at least when food is in short supply. Not only the morphological transformation but also the maintenance of the anti-predator phenotype were energetically costly for Euplotes, the cost being proportional to the defence level. The morphological transformation was affected by the kind of food (algae) provided to the prey. Ciliates fed Chlorogonium elongatum attained their maximum width sooner than those fed Chlamydomonas. Thus, both the quantity and the quality of the food available may significantly affect the magnitude of response and therefore the potential success of an induced defence.