Biphasic Geographic Variation in Sexual Size Dimorphism of Turtle (Mauremys leprosa) Populations Along an Environmental Gradient in Morocco

• DOI: 10.2744/ccb-0788.1
• Publication Date: 2010-06-18T20:14:35Z
• Authors: Jeffrey E. Lovich; Mohammed Znari; Moulay Abdeljalil...; Mohamed Naimi; Abdelouahab Mostalih
• Keywords: Sexual dimorphism

The varying influences of selective forces throughout a species' range can result in geographic variation sexual size dimorphism (SSD). Moroccan turtle, Mauremys leprosa, occupies an extremely wide variety ecoregions and habitats, including coastal rivers, mountain streams, oases, intermittent rivers the northern fringe Sahara Desert. To assess SSD, we collected specimens along environmental gradient central Morocco, Oued (River) Ksob on Atlantic coast, Zat High Atlas Mountain foothills, Drâa Only turtles with conspicuous secondary characteristics were included our analysis. We calculated index (SDI) using mean larger sex divided by smaller subtracted one from that ratio. direction SSD was biphasic: population males females exhibited same body size, whereas, two other populations, than males. Mean straight-line carapace lengths not statistically different at (SDI = 0.08), relatively small. In contrast, significantly 0.56) those Ksob. most dramatic 0.92) much greater any value previously reported for species, exhibiting length 2 rivers. A × 3 factorial analysis variance compared sexes among sites yielded significant SEX LOCALITY interaction (p < 0.001), which demonstrated SSD. Geographic appears to represent natural selection growth rates maturity schedules environments.