Biometric relationships between body size and otolith size in 15 demersal marine fish species from the northern Brazilian coast

Rory Romero De Sena Oliveira,Fabiola Seabra Machado,Marcelo Costa Andrade,Flaviane Souto De Freitas,Élida Jesana Santana Cunha,Ulrich Saint-Paul,Alex Garcia Cavalleiro De Macedo Klautau,Tommaso Giarrizzo

doi:10.1590/1809-4392201900571

Abstract

ABSTRACT The relationships between fish size and sagitta otolith measurements were calculated for the first time for 15 species belonging to six families from the northern Brazilian coast. A total of 220 fish were sampled from the bycatch landed by the bottom-trawl industrial shrimp-fishing fleet between August and September 2016. All species had strong relationships between otolith measurements and fish total length with the coefficient of determination (r 2) ranging between 0.71 and 0.99. The variable most strongly related to fish total length was found to be the sagittal otolith length (OL) with 98% of the variability. These relationships are a useful tool to estimate length and mass of preyed fish from otoliths found in stomach contents of marine predators.

Highlights

Otoliths are structures composed mainly of calcium carbonate, located in the inner ear of Osteichthyes, which have body balancing and hearing as main functions (Campana 2004). These structures are arranged in pairs, called sagitta, asteriscus, and lapillus in bony fish, and vary widely in size and shape among species (Campana 2004; Popper et al 2005)
Due to its largest size in the majority of bone fishes, sagittae otoliths are the most suitable for systematic and ecological studies, for taxon identification, age estimation, and life history tracking (Harvey et al 2000; De La Cruz-Agüero et al 2016; Assis et al 2018). Their nondigestible calcified structure has allowed them to be widely used to identify fishes ingested by different predators such as aquatic mammals, seabirds and fishes (Battaglia et al 2010; Tuset et al 2010)
Samples were randomly collected from the bottom trawl of industrial shrimp trawlers using a 30 x 21 mm mesh bottom trawl of 22.4 m length towed at velocity of ~2.5 knots at 35 ‒ 49 m depth

Summary

Introduction

Otoliths are structures composed mainly of calcium carbonate, located in the inner ear of Osteichthyes, which have body balancing and hearing as main functions (Campana 2004) These structures are arranged in pairs, called sagitta, asteriscus, and lapillus in bony fish, and vary widely in size and shape among species (Campana 2004; Popper et al 2005). Due to its largest size in the majority of bone fishes, sagittae otoliths are the most suitable for systematic and ecological studies, for taxon identification, age estimation, and life history tracking (Harvey et al 2000; De La Cruz-Agüero et al 2016; Assis et al 2018) Their nondigestible calcified structure has allowed them to be widely used to identify fishes ingested by different predators such as aquatic mammals, seabirds and fishes (Battaglia et al 2010; Tuset et al 2010). Relationships between fish size and otolith measures are useful to elucidate the feeding behavior of piscivorous fauna, providing subsidies for the management of these species (De Pierrepont et al 2005; Lombarte et al 2006; Battaglia et al 2010).

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Conclusion