Length-Weight and Length-Length Relationships of 39 Demersal Fish Species of an Estuarine-Coastal Ecosystem from the Northwestern of the Baja California Peninsula, Mexico

The length-weight (LW) and length-length (LL) relationships of 39 demersal fish species belonging to 19 families were calculated. Fish samples were collected monthly during the open (September–February) and close (March–August) shrimp fishing seasons from 2014 to 2022 by the artisanal fishery in the Bahía Magdalena-Almejas lagoon system (BMA), using small boats and a shrimp bottom trawl with 16–17 m top rope and 38 mm mesh opening. Total (TL) and standard (SL) lengths and total weight (TW) were measured for all fish specimens. The b parameter of the LW relationship ranged from the minimum of 2.483 for Cynoscion parvipinnis to 3.775 as the maximum for Bagre panamensis while, for the LL relationship, the parameter b ranged from 0.685 for Balistes polylepis to 0.994 for Orthopristis cantharinus. Both LW and LL relationships were highly correlated (r² > 0.95; P < 0.05). The parameter b of the LW relationship indicated that 59% of the fish species showed isometric and 41% allometric growth. Information on LW and LL relationships is updated for thirteen species, and four are reported for the first time: Citharichthys xanthostigma, Ophidion galeoides, Pleuronichthys guttulatus, and P. ritteri. This study will be useful to update the LW relationship parameters for data-poor fish species and contribute to the accuracy of fish stock assessment in the BMA fisheries.