Aim: The aim of the present study was to evaluate the differential beating rate of the parasite Leucochloridium within the tentacle of the infected snail Succinea daucina and Indosuccinea semiserica under different photoperiodic conditions. Methodology: In this study, the rhythmic beating pulse of sporocyst of the parasite invading the tentacle of the snail was recorded from multiple snails, periodically in light and dark hours. The numbers of beat per minute were subjected to univariate ANOVA using day and photoperiod as explanatory variables. A two-sample t-test was performed with the mean of pulse rate in light and dark phase to estimate the significant differences between the same. Results: The observations revealed that sporocyst brood sac of I. semiserica beat mean 99.23 ± 1.91 SE per minute ( 90 – 101) in day hours and mean 76.57 ± 4.64 SE per minute (48 – 88) in the night hours (n = 7 observations). In S. daucina, the sporocyst brood sac beat 65.85 ± 2.17 SE per minute (25 – 94) during day and 30.5 ± 3.55 SE per minute (0 – 80) in night (n = 9 separate observations). The beats of the sporocyst varied significantly diurnally and with the consecutive days revealed through t-test and ANOVA. Interpretation: Apparently, the colourful sporocyst broodsac of Leucochloridium faster beating rate under light may attract definite host, the insectivorous birds which prey on the Leucochloridium sporocycst disrupting the snail tentacle. Thus, the pulsating sporocyst inside the tentacle makes the infected host snail more conspicuous for the birds, linking the snail- Leucochloridium- bird cycle. Key words: Indosuccinea semiserica, Intermediate host, Land snail, Leucochloridium sp., Succinea daucina, Trematoda