Development of Standard Weight Equations for Caribbean and Gulf of Mexico Amphidromous Fishes

Abstract

We collected and compiled length and weight information from four countries and one commonwealth to develop standard weight (W_s ) equations for three amphidromous fish species native to the Caribbean and Gulf of Mexico regions: mountain mullet Agonostomus monticola (N = 9,768 individuals, 52 populations), river goby Awaous banana (N = 1,847 individuals, 62 populations), and bigmouth sleeper Gobiomorus dormitor (N = 2,983 individuals, 53 populations). Linear and quadratic W_s equations for three quartiles (25%, median, 75%) are presented for these three species. The length–weight relationship from eight lentic bigmouth sleeper populations was significantly different from that of lotic populations, reflecting higher weights of juvenile fish (<70 mm total length) in lentic environments. Thus, independent W_s equations were developed for lotic populations of bigmouth sleepers. W_s equations were not developed from lentic bigmouth sleeper populations alone due to the low number of applicable populations caused by life history constraints; the equation from combined lentic and lotic populations is suggested for application to lentic bigmouth sleeper populations. These morphometric relationships for amphidromous fishes may improve the ability to assess existing and potential sport fisheries and allow ecological assessment based on fish condition.