This study was carried out to throw some light on the effect of different
photoperiod levels, 6, 12 and 24 hours as well as natural light on the rate of food
consumption by the glassy clover snail Monacha cartusiana (Maller) under laboratory
conditions to know its feeding capacity. Data indicated that the rate of food
consumption differs according to photoperiod and season of activity. This snail during
the end of its season activity (May & June months 2005) fed in light and dark with
slightly differs rate of food consumption during the photoperiod 6 or 12 or 24 hour and
without any significant as well as the range of food consumption in different
treatments approximately similar. It was found that the rate of food consumption of the
same snails' group averaged 113 & 113.5 mm² during feeding under six hours dark
and light from 6.0 a.m. to 12.0 a.m. respectively; while this rate averaged 118.5 &
102.7 mm² under the same six hours dark and light from 6.0 p.m. to 12.0 p.m.
respectively. At 12.0 hour dark and light this rate averaged 134.2 & 121.5 mm² from
6.0 a.m. to 6.0 p.m. respectively; while it averaged at the same period 153.0 & 107.2
mm² from 6.0 p.m. to 6.0 a.m. respectively. On the other hand, the daily rate of food
consumption averaged 73.5 & 45.4 mm² under 24 hour complete dark and natural
light respectively; while it averaged 157.8 & 57.2 mm² under 24 hour complete light
and natural light respectively. While during its active season (November & December
months 2005), this snail consumed on rate averaged 328.0 & 161.7 mm² when
feeding during 24 hour of complete light and complete dark (day after day). On the
other hand this rate averaged 174.0 mm² during natural light.