Variations saisonnières comparées de l’activité sexuelle (données pondérales) chez deux espèces de Rongeurs (Psammomys obesus et Gerbillus gerbillus) du Sahara occidental algérien

Abstract

In the same western Algerian Sahara area, the sand rat (P. obesus) and the gerbil (G. gerbillus) presented important seasonal weight variations of their reproductive systems, but these vatiations were different for the 2 rodents. The most important development of the testes and seminal vesicles was in autumn and winter, and in the beginning of spring for P. obesus; it was limited to spring for G. gerbilus. The weight regression of these organs was earlier for the sand rat (March-April) than for the gerbil (May-June). If the lowest weight occurred in July for Psammomys the regression, although very important in this same period, continued until the beginning of Nov. in a very few gerbils. Weight changes started in Sept. in the sand rat, while in Feb. in the gerbil. Pregnancies lasted from Oct.-May in P. obesus and from mid Feb.-mid July in G. gerbillus. There was an important differences between these 2 spp. which live in the same geographical area but have different rhythms of activity and diet: from autumn to the beginning of spring P. obesus was in sexual activity while the reproductive system of G. gerbilus was in a period of regression or atrophy.