This report is a summary of a study of the possible effect on larval flukes when their snail hosts are subjected to the stress of altering daylight hours. Some cercaria emerge from snails only during the late afternoon. The time of emergence is undoubtly correlated with the circadaian rhythms of their hosts. It would seem that shortening the number of daylight hours would result in a change in the numbers or cercariae released from a snail at any one time during the day. Project Number 103.
Noble, Glenn A.
"Stress and Snail Trematode Larvae,"
Jackson Hole Research Station Annual Report: Vol. 1972
, Article 29.
Available at: http://repository.uwyo.edu/jhrs_reports/vol1972/iss1/29