Length–weight relations (LWR) are presented herewith for 15 fish species from shallow waters of three sandy beaches in the lower Guanabara Bay estuary, south-eastern Brazil. The following species were examined: Albula vulpes (Linnaeus, 1758); Harengula clupeola (Cuvier, 1829); Brevoortia aurea (Spix et Agassiz, 1829); Anchoa lyolepis (Evermann et Marsh, 1900); Umbrina coroides Cuvier, 1830; Menticirrhus littoralis (Holbrook, 1847); Menticirrhus americanus (Linnaeus, 1758);  Trachinotus carolinus (Linnaeus, 1766); Trachinotus falcatus (Linnaeus, 1758); Diplodus argenteus (Valenciennes, 1830); Polydactylus virginicus (Linnaeus, 1758);  Mugil curema Valenciennes, 1836; Haemulon aurolineatum Cuvier, 1830; Haemulon steindachneri (Jordan et Gilbert, 1882); Sphoeroides testudineus (Linnaeus, 1758). Specimens were sampled monthly over a four-year period between January 2012 and December 2015. This study presents the first length–weight relation of Diplodus argenteus for Brazil. The LWRs for all taxa included juveniles and sub-adults within size ranges commonly found in shallow waters of tropical sandy beaches. Only the adults (TL > L50) of Harengula clupeola and Sphoeroides testudineus were recorded in the area. The length–weight parameter b for all species ranged from 2.66 to 3.32, with regression coefficients (r2) between 0.97 and 0.99.

ichthyofauna, sandy beach, south-eastern Brazil, growth