Resumen:
Clutch size (CS) and relative clutch mass (RCM) are considered important features in life history descriptions of species within Squamata. Variations in these two characteristics are caused by both biotic and abiotic factors. The present study provides the first account related to CS and RCM of Basiliscus vittatus in Mexico within a population that inhabits an open riverbed juxtapositioned to tropical rainforest habitat in Catemaco, Veracruz, Mexico (170 m a.s.l.). Twenty-nine gravid females were collected and kept in captivity under favorable conditions that promote oviposition. The CS within this population was 6.2 ± 0.2 and was correlated posi- tively with snout vent-length (SVL); while the RCM was 0.17 ± 0.006 and was correlated positively with both CS and width of egg. Factors, such as female morphology and environmental conditions, should influence these reproductive traits in B. vittatus. The data collected in this study could provide a framework for comparisons of the life history traits across populations of B. vittatus in Mexico and within other species of the family Corytophanidae and provide a model for testing how abiotic and biotic factors may influence the CS and RCM in basilisk lizards throughout their range.