&lt;b&gt;Lapillus otoliths of the &lt;i&gt;Cathorops spixii&lt;/i&gt; (Spix &amp; Agassiz, 1829) and &lt;i&gt;Genidens genidens&lt;/i&gt; (Cuvier, 1829) (Actinopterygii - Ariidae)

Barbara Maichak De Carvalho,Alejandra Volpedo,Marco Fábio Maia Corrêa

doi:10.4025/actascibiolsci.v36i3.21117

Lapillus otoliths of the Cathorops spixii (Spix & Agassiz, 1829) and Genidens genidens (Cuvier, 1829) (Actinopterygii - Ariidae)

Barbara Maichak De Carvalho, Alejandra Volpedo + Show 1 more

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https://doi.org/10.4025/actascibiolsci.v36i3.21117

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Abstract

The aim of this study was to analyze the morphology and morphometry of lapillus otoliths of the catfishes Cathorops spixii and Genidens genidens from the coast of Parana State, Brazil. We used 147 lapillus from C. spixii and 96 from G. genidens, of different size classes. Otoliths were characterized with smooth margins for both species but with different shapes: oblong for C. spixii and oval for G. genidens. The morphological differentiation between the two species is in the anterior region: rounded for C. spixii and pointed for G. genidens. The t-test results for otolith measurements were: length (t value = -2.88; p = 0.0042), height (t value = -6.87; p < 0.000001), anterior angle (t value= 9.84; p = 0.000001) and posterior angle (t value =0.41; p = 0.68). The results show that lapillus otoliths of C. spixii and G. genidens differ in the shape of the anterior region and in the anterior angle, which facilitate the differentiation between the two species in trophic ecology studies on ichthyophagous.

Highlights

Otoliths are endogenous calcareous structures usually made up of aragonite, and located in the inner ear of bony fish (POPPER et al, 2005)
The present study aimed to describe the morphology and morphometry of the lapillus otolith of Cathorops spixii and Genidens genidens (BARLETTA et al, 2008; FÁVARO et al, 2005), in order to facilitate the identification of these species and the estimation of the size of fish in stomach contents of ichthyophagous animals
Were show the means and standard deviations of the measurements of otoliths. The lapillus of both species was characterized by smooth margins and absent sulcus acusticus, oblong shaped for C. spixii and oval shaped for G. genidens (Figure 3)

Summary

Introduction

Otoliths are endogenous calcareous structures usually made up of aragonite, and located in the inner ear of bony fish (POPPER et al, 2005). Bony fish have three otolith pairs, sagitta, lapillus and asteriscus, named according to their shape and position relative to the inner ear. They are important structures used to estimate the age of fish by counting the rings (CORREA; VIANNA, 1992; FRANCIS; CAMPANA, 2004; NIELSEN; JOHNSON, 1983). Otoliths are used in studies on fish stock determination (AVIGLIANO; VOLPEDO, 2013; AVIGLIANO et al, 2014; VOLPEDO; FERNANDEZ-CIRELLI, 2006)

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