You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
Vertical Distribution of an Estuarine Snail Altered by a Parasite
Lawrence A. Curtis
New Series, Vol. 235, No. 4795 (Mar. 20, 1987), pp. 1509-1511
Published by: American Association for the Advancement of Science
Stable URL: http://www.jstor.org/stable/1699055
Page Count: 3
Preview not available
Estuarine snails Ilyanassa obsoleta bearing larvae of the trematode Gynaecotyla adunca behave singularly in comparison with conspecifics lacking this parasite. Following high tides, and especially at night, infected snails were found stranded high on beaches and sandbars. Semiterrestrial crustaceans living well up on the shore serve as the next host, and the modified (induced) snail behavior is apparently a parasite adaptation facilitating cercarial transmission to these crustaceans. The altered behavior is unusual because of its apparent enhancement of host-to-host transmission by cercariae rather than predation, the process commonly recognized as being enhanced by parasitic modification of host behavior.
Science © 1987 American Association for the Advancement of Science