Dimorfismo sexual y relaciones morfométricas de Atlantoraja platana (Günther, 1880) en aguas del golfo San Matías, Patagonia

the skate atlantoraja platana, commonly known in argentina as "raya platana", is endemic to the southwest atlantic. it is distributed from brasil (24°s) to north patagonian waters (42°11's). in this study the morphometric aspects of this skate were described. in the san matías gulf (41°-42°s y 64°-65°w), a total of 778 females and 709 males were sampled from different sources between 2004 and 2006. the total length ranged was 19 to 89 cm for females and 19 to 79 cm for males. atlantoraja platana was sexually dimorphic in total length-weight and total length-disc width relationships. since 41 cm onwards the females are being heavier than males. the total length-weight relationship was pt= 0.0132 x lt2.91 for females and pt= 0.0222 x lt2.77 for males. the total length-disc width relationship was dw= 7.27 + 0.762lt for females and dw= 7.768 + 0.798lt for males. this is the first report of morphometric relationships of this species in the argentinean sea and they should be used for comparison purpose between different latitudinal localizations of this skate.