Ecological observations on two species of Gastropoda (Family Hygromiidae) : Monacha cantiana and Candidula gigaxii In three central Iraq provinces

This study was carried out on two species of the Hygromiidae family Monacha cantiana and Candidula gigaxii collected from six sites in three central Iraq provinces (Baghdad , Babylon and Karbala) . A total of 1318 individuals of Monacha cantiana and 173 of Candidula gigaxii have been examined during the study period from October 2013 to July 2014.The study included estimation of species relative abundance, population density and relationship with some physico- chemical properties of the soil; temperature, moisture and pH. The Monacha cantiana was present at all sites but with varying numbers, while Candidula gigaxii was confined to only three sites: Aljadiriyah and Zafaraniya at Baghdad, and Hindiya dam at Babylon. Results showed that the highest relative abundance of Monacha cantiana was 60.8% in April 2014 at Al-Al-Hussainia, Karbala and the lowest was 12.6% in January 2014 at Zafaraniya, Baghdad. The highest value of relative abundance of Candidula gigaxii was 51.9 % in January 2014 at the Zafaraniya , Baghdad and the lowest value was 7.3 % in March 2014 at Hindiya dam , Babylon. Population density of Monacha cantiana showed that highest value was 12.5 individual / m^2 in January 2014 at Al-Al-Hussainia, Karbala and the lowest value was 0.8 individual / m^2 in October 2013 at Aljadiriyah , Baghdad. Highest population density of Candidula gigaxii was 13.6 individual / m^2 in December 2013 at Zafaraniya, Baghdad, and the lowest was 0.4 individual / m^2 in October 2013 in Aljadiriyah, Baghdad. Soil temperature varied between 7and 30 C° in January and July 2014 at Twereje, Karbala, and Aljadiriyah at Baghdad respectively. Moisture values were between 9 and 33% in July and January 2014 at Alexandria and Hindiya dam, Babylon, respectively. Values of pH varied from 7.31 to 7.96 in December 2013 and July 2014 at Alexandria, Babylon and Zafaraniya, Baghdad respectively. These results showed that ecological factors may have affected abundance and population density of the snails at all of the study sites .