Length–weight relationships for 22 crustaceans and cephalopods from the Gulf of Cadiz (SW Spain)

Life history traits are available for many fish species in different regions, but less so for invertebrates such as cephalopods and crustaceans, though, they are increasingly needed for implementing an ecosystem-based approach. Recent food web modelling in the Gulf of Cadiz has identified invertebrates as keystone groups. However, information on life history traits of such groups remains incomplete in this region. To fill this knowledge gap, we report length-weight relationships for 12 cephalopods and 10 crustaceans collected in the Gulf of Cadiz from 2009 to 2013. This study reports, for the first time, life history traits of nine species in the area (Chlorotocus crassicornis, Pasiphaea sivado, Plesionika heterocarpus, Plesionika martia, Processa canaliculata, Solenocera membranacea, Allotheutis media, Sepia orbignyana and Sepietta oweniana). For each species, length-weight relationships, minimum and maximum lengths, mean weights, and depth ranges are presented. Overall, the results revealed that all species showed negative allometric growth (hypoallometry), except P. sivado, the only species showing an isometric growth pattern. We expect that this study will contribute to link sustainable fisheries with biodiversity conservation goals enabling the implementation of operational ecosystem-based management in the Gulf of Cadiz.