Identification of Mollusca Species along the Karaj River in Alborz Province

In the course of the survey of mollusk fauna associated with the Karaj River in Alborz province of Iran and the collections made in the period 2015-2016, the fauna of snails was investigated. Specimens were mainly collected and studied using conventional methods such as sampling nets and direct collection by hand from aquatic plants, rotten substrates, shrubs, and weeds along the river. A total of 19 species of snails were identified for the first time from the Karaj River in Alborz Province, which belonged to 11 genera from 8 families and based on morphometric characteristics (including shape, size of shell, the dextral and sinistral position of the shell, operculum, aperture, radula, mucus color, respiratory pore, keel, renal ridge, and reproduction system). The most and least distribution among the identified snail species were 15 and 7 species belonging to Stations 2 and 7 of the Karaj River, respectively. The most commonly-distributed family was Lymnaeidae with 4 species of Lymnaea truncatula, Lymnaea gedrosiana, Lymnaea palustris, and Lymnaea pereger. Also, among the identified species, Lymnaea truncatula was the most frequent and had medical applications in the transmission of parasitic diseases in humans and Lymnaea truncatula. Gyraulus chinensi species was reported for the first time from Iran. All samples along with all relevant spatial and temporal information are available in the Museum of Agricultural Zoology Research Department of the Iranian Plant Protection Research Institute.