Reproduction and sexual dimorphism in two populations of Sceloporus minor of the Guadalcázar Region, San Luis Potosí, Mexico

Abstract

We studied the reproduction and sexual dimorphism of Sceloporus minor in two populations, El Oro and Las Lagunas, in the municipality of Guadalcazar, San Luis Potosi, Mexico. Males were larger and had larger heads and tibias than females. Males and females from El Oro were larger than those from Las Lagunas. Reproductive activity of males and females was asynchronous in both populations. Testes of the males from El Oro and Las Lagunas increased in size from July to September, reaching maximum size in October and regressing in November. Vitellogenesis occurred in September in both populations, with ovulation occurring in November-December. Embryonic development was observed from December to March in both populations. Parturition in the El Oro population occurred from late March to early July, whereas in Las Lagunas it occurred from mid-March to late May. Litter size for both populations was similar (El Oro: 6.6, Las Lagunas: 6.2). Litter size was positively related to female SVL in the El Oro population but not in the Las Lagunas population. These two populations show some similarities, but also show differences, possibly due to elevation.