Length-weight and length-length relationships for three small tuna species (Scombridae) from Portuguese waters including curved fork length and eviscerated weight relationships

This study reports length-weight (LWRs) and length-length (LLRs) relationships for three small tuna species, Scombridae: Bullet tuna [BLT], Auxis rochei (Risso, 1810); Atlantic bonito [BON], Sarda sarda (Bloch, 1793); and Little tunny [LTA], Euthynnus alletteratus (Rafinesque, 1810) from Portuguese waters. Specimens were captured by tuna trap, trawl nets and gill nets. A total of 1035 individuals were sampled and the sex was identified in 662. This study provides the first LLRs using the curved fork length (CFL) for these three species and the first LWRs using the eviscerated weight (We) for Bullet tuna. Additionally, in relation to the available information on sexed LWRs and LLRs in FishBase, this study is a first report for Bullet tuna and Little tunny and a first report for Atlantic bonito in the Atlantic Ocean. This work also improves data available for the north-eastern Atlantic and Portuguese waters for these three species.