Scales of variability in fin ray counts of flounder, Platichthys flesus L. on Irish and welsh coasts

Meristic variation within a fish species can arise due to environmental factors and can aid investigation between fish stocks and closely related juvenile fish species. The aim of this study was to investigate the spatial variation in meristic characteristics for juvenile flounder Platichthys flesus from Irish and Welsh coasts. Five meristic fin ray counts were taken from 120 fish from nursery grounds in three regions (west Irish coast, east Irish coast and Welsh coast). Statistical analysis revealed regional variability for two of the meristic counts (dorsal and anal fin rays). A discriminant function analysis revealed a weak separation of the three regions. This separation improved when samples from the east Irish region were eliminated, with 65% of the fish from the Irish west coast and 73% of the fish from Wales correctly classified.