Age and growth of the undulate ray, Raja undulata, in the Algarve (Southern Portugal)

Aspects of the population dynamics of the undulate ray, Raja undulata (Chondrichthyes: Rajidae), one of the more abundant elasmobranch ¢shes captured along the Portuguese south coast (Algarve), were studied for the ¢rst time. Some traditional elasmobranch vertebral enhancing techniques were compared and the most precise for this species determined to be the cedar wood oil immersion and the alizarin red S stain. The sample consisted of 14 age classes, with age classes 3 to 8 being the most represented. Evidence of an annual deposition pattern of a pair of bands (one opaque and one translucent) was found by marginal increment analyses.Von Bertalan¡y growth parameters were estimated and no di¡erences found between males and females (all data: Linf1⁄4110.22 cm, K1⁄40.11 year71 and t01⁄471.58 year).