Ecological Studies on Some Land Gastropod Species at Zagazig District, Sharkia Governorate

Abstract

Survey, population structure of some land snails' species in five different localities at Zagazig district, Sharkia Governorate were studied. A field survey was carried out at Sharkia Governorate in Sheeba, Banayous, El-Aslogy, Kafr El-Hosor and Kafer El-Zagazig villages during the period from November 2013 to May 2014. Results revealed that only two species of terrestrial snail were found, Monacha cartusiana that showed a very wide distribution range in all surveyed villages than Succinia putris which appeared only in Kafer El-Zagazig. Highly dense population of snails were found on the Egyptian clover, followed by lettuce, cabbage while wheat, maize and rice showed less numbers. The initial infestation of the Egyptian clover with M. cartusiana was appeared in September with low numbers (1.33 and 4.33 snails) per quadrate sample, reaching its maximum in April with values of 64.80 and75.80 per quadrate sampleduring the growing season of 2013/2014 and 2014/2015, respectively. Population dynamics of adults and juveniles M. cartusiana fluctuated during the different seasons, whereas population density remained at partially low numbers during winter months, gradually increased during spring till reached a peak of 40.40 and45.80 snails/0.25m2 by the beginning of April for juveniles and of 37.80 and43.20 snails/0.25m2 for adults in mid-April during 2013/2014 and 2014/2015, respectively. It declined thereafter during Sept. and Oct.(0.0,1.3 and 0.0, 4.3)and (0.0,6.67and0.0, 11.33 snails/0.25m2), for juvenile and adult snails during 2013/2014 and 2014/2015 respectively. In addition, there is no definite correlation between temperature or relative humidity and population density of M. cartusiana during the two successive growing seasons.