Torres-Palacios et al.: Age and growth parameters of Urotrygon aspidura 
177 
its abundance, analyses of the reproductive biology and 
demography of the Panamic stingray are necessary to 
define its real vulnerability to fisheries activities. 
Acknowledgments 
Funding for this study was provided by Colciencias- 
Colombia (RC 156-2010), Padi Foundation, and Inicia- 
tiva de Especies Amenazadas. We thank H. Paredes, F. 
Cuero, and SQUALL'S staff for support with field work. 
The senior author was funded by scholarships from the 
Consejo Nacional de Ciencia y Tecnologia (Mexico) and 
Instituto Politecnico Nacional (IPN) for studies toward 
her master’s degree. C. Quinonez and V. Cruz were sup¬ 
ported by IPN programs, Estfmulos al Desempeno de los 
Investigadores and Comision de Operacion y Fomento de 
Actividades Academicas. 
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