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

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.

Population structure and dynamics of the Mediterranean Pond Turtle Mauremys leprosa (Schweigger, 1812) in contrasted polluted aquatic environments

“…In addition, the sex ratio was male-biased downstream of the WWTP. Our results thus supported our first hypothesis, i.e., the primary driver of the population structure and dynamics of the study population is WWTP-induced resources, consistent with previous findings (El Hassani et al, 2019;Gahmous et al, 2022;Naimi et…”

“…The densest recorded populations are mostly located in heavily degraded environments, where turtles appear to benefit from water, organic matter, and macroinvertebrate supplies provided by the pollution sources (El Hassani et al, 2019). Because J o u r n a l P r e -p r o o f the body size and reproductive output of M. leprosa are enhanced in environments degraded by organic waste and pollutants coming from industrial, agricultural, and urban sources, this species appears to be well adapted to pollution (Da Silva, 1995;El Hassani et al, 2019;Gahmous et al, 2022;Naimi et al, 2012). As a result of its tolerance to high levels of pollution and eutrophication of its habitat, M. leprosa has been proposed as a biological indicator of pollution (El Hassani et al, 2019).…”

Distribution and Conservation Status of European Pond Turtles Emys orbicularis (L., 1758) in Algeria

“…The European pond turtle, Emys orbicularis (Linnaeus, 1758) (Emydidae Rafineque, 1815), is one of three native chelonians to Algeria, the second being the Mediterranean stripe-necked turtle Mauremys leprosa (Schweigger, 1812), and the third being the terrestrial spur-thighed tortoise Testudo graeca Linnaeus, 1758 [1][2][3][4]. Morocco, Tunisia, and Algeria are the southernmost areas where E. orbicularis occurs [5].…”