Reproductive Traits Demonstrate How Well the Mediterranean Stripe-Necked Turtle Mauremys leprosa Can Flourish under Highly Degraded–Polluted Conditions

SIMPLE SUMMARY: The Mediterranean stripe-necked turtle Mauremys leprosa is known to possess physiological mechanisms allowing it to adapt without particular signs of physiological disorder or stress in habitats with high pollution. Nevertheless, we were uncertain about the costs of this adaptation and its impact on reproduction. The reproductive traits measured in this study suggest the adaptation of M. leprosa to flourish well in highly degraded–polluted areas compared to undisturbed habitats. M. leprosa was so well adapted to the pollution that the exposed population actually increased its reproductive capacity. Females living in the highly degraded–polluted habitat exhibited record body sizes for the species, which allowed them to carry both more and larger eggs. In comparison, the corresponding reproductive traits measured in the intact habitat ranged within the limits reported in previous studies. ABSTRACT: We measured and compared the reproductive traits of the Mediterranean stripe-necked turtles Mauremys leprosa living in highly degraded–polluted vs. intact natural habitats in Algeria. Data on reproduction were obtained by using X-ray examination of gravid females and examination of nests. The results were opposite to the negative trend confirmed in most freshwater turtles exposed to pollution and suggested the ability of this species to flourish instead in highly degraded–polluted habitats. An optimum development was recorded for several reproductive patterns of the studied freshwater turtle under conditions considered uninhabitable for other vertebrates. Females exhibited record body sizes among conspecifics, which allowed them to carry significantly larger clutches, exceeding by up to 3 eggs the previously largest reported clutch. The mean clutch size (8.79 ± 2.70 eggs) was also higher than findings from previous studies, except for in some other polluted habitats. Furthermore, large females even with large clutches carried large eggs. Egg measurements in the disturbed habitat revealed new records exceeding those previously noted; in egg length (by 3.0 mm), egg width (by 2.8 mm), egg mass (by 1.8 g), and clutch mass (by 18.6 g). In comparison, the usual reproductive performances were observed in the intact natural habitat; female body sizes were significantly smaller and carried fewer eggs of smaller size.