Age, growth, and latitudinal patterns of two Rajidae species in the northwestern Atlantic: Little skate (Leucoraja erinacea) and winter skate (Leucoraja ocellata)

Vertebral samples of little skate (Leucoraja erinacea) and winter skate (Leucoraja ocellata) were collected from Cape Hatteras, USA, to Canadian waters to estimate age, growth, and length at weight relationships for both species throughout this range. Maximum observed age was 12.5 and 20.5 years for little skate and winter skate, respectively. Significant length at weight relationships were found for both species, von Bertalanffy growth curves for the northwestern Atlantic were estimated for little skate (k = 0.19, L_∞ = 56.1 cm, t₀ = -1.17, p < 0.0001, n = 236) and winter skate (k = 0.07, L_∞ = 122.1 cm, t₀ = -2.07, p < 0.0001, n = 229). Additionally, latitudinal patterns in size and growth were observed in little skate, with individuals in northern regions growing slower and reaching a larger asymptotic size: von Bertalanffy growth estimates (mid-Atlantic, k = 0.22, L_∞ = 53.26 cm, t₀ = -1.04, p < 0.0001; southern New England - Georges Bank, k = 0.20, L_∞ = 54.34 cm, t ₀ = -1.22, p < 0.0001; Gulf of Maine, k = 0.18, L _∞ = 59.31 cm, t₀ = -1.15, p < 0.0001). Although differences were observed for sex-specific growth curves for both species, only winter skate curves were significantly different.