Résumé:
The current study represents a demographic study of "the black limpet" Cymbula safiana (lamarck 1819) on Mostaganem coasts.
A comparison has been committed with anterior data of two different zones (Kharouba and port of Salamandre) in order to compare them with the data collected in Sidi Medjdoub station.
Ten transects of 10m were used, at the level of the station of Sidi Medjdoub revealing the presence of 298 individuals.
An ANOVA was carried out in order to study the effect of "geographical distance" between the three stations, while a Student's test was used for the effect of "nature of the substratum" (natural or artificial).
The results of this work reveal that there is a much higher population density of Cymbula safiana on artificial substratum (breakwaters) than on natural ones. This indicates that the breakwaters of Salamandre and Sidi Medjdoub can act as a preferred environment for C. safiana.
On the other hand, no effect of distance between the Kharouba, Sidi Medjdoub and Salamandre stations was detected. Finnaly, a study in much wider areas could give a more conclusive result in the future.
