Discrimination of red porgy Pagrus pagrus (Sparidae) potential stocks in the south‐western Atlantic by otolith shape analysis

Abstract

Otolith shape analysis is a powerful method for fish stock identification. We compared the otolith shape of Pagrus pagrus (Linnaeus 1758) along with its distribution in four south‐western Atlantic regions where it is commercially fished: Rio de Janeiro, Rio Grande do Sul in southern Brazil, the Argentine‐Uruguayan Common Fishing Zone (UA) and the Argentinian Exclusive Fishing Zone (AR). Otolith shapes were compared by Elliptical Fourier and Wavelet coefficients among specimens in a size range with similar otoliths, morphometric parameters and ages. Four potential stocks were identified: one in the AR, a second along the UA which included specimens from southern Brazil with well‐marked opaque bands in its otoliths (MRS), the third in southern Brazil with faint or absent opaque bands in its otoliths (FRS) and the fourth along Rio de Janeiro. The difference in the otolith shape among regions followed differences reported using other stock identification techniques. The similarity between otoliths from UA and MRS (ANOVA‐like, P > 0.01) can be explained by seasonal short‐range migrations. Otoliths shape differences between MRS and FRS (ANOVA‐like, P < 0.01) suggest that P. pagrus does not form a homogeneous group in southern Brazil.

Comparing otolith shape descriptors for population structure inferences in a small pelagic fish, the European sardineSardina pilchardus(Walbaum, 1792)

“…As a result, small features in specific areas of the shape can only be detected and considered in the DWd case, which may discriminate differently between locations. DWd has been increasingly used more recently, not only for stock determination Kikuchi García et al, 2021;Libungan et al, 2015aLibungan et al, , 2015bSadeghi et al, 2020;Sadighzadeh et al, 2014;Saltalamacchia et al, 2022;Song et al, 2018;Wiff et al, 2020) and the Adriatic and Ionian Seas together. Because no genetic population structure seems to exist for this species (see Kasapidis, 2014) and in these areas (Tinti et al, 2002), the lack of extensive migrations between feeding and spawning spots (Giannoulaki et al, 2011) Vignon & Morat, 2010).…”

“…As a result, small features in specific areas of the shape can only be detected and considered in the DWd case, which may discriminate differently between locations. DWd has been increasingly used more recently, not only for stock determination (Kikuchi, Cardoso et al ., 2021; Kikuchi García et al ., 2021; Libungan et al ., 2015a, 2015b; Sadeghi et al ., 2020; Sadighzadeh et al ., 2014; Saltalamacchia et al ., 2022; Song et al ., 2018; Wiff et al ., 2020) but also especially for species identification (Lin & Al‐Abdulkader, 2019; Parisi‐Baradad et al ., 2005, 2010; Sadighzadeh et al ., 2012; Ugrin et al ., 2021) and regional phenotypical variability studies (Tuset et al ., 2019). Although DWd and EFd effectively represent the overall characteristics of the otolith shape, which has already been verified in the present and previous works (Libungan & Pálsson, 2015a; Song et al ., 2018), due to the characteristics of these descriptors, Sadighzadeh et al .…”

Age, growth, and biomass projections of red porgy Pagrus pagrus (Teleostei, Sparidae) after the fishery collapse in southern Brazil

“…The red porgy is a target of commercial and recreational fisheries throughout its range, with more than half of global catches from the southwestern Atlantic (SWA), where it is fished from northern Argentina to southeastern Brazil with bottom trawls, gillnets, hook and line, and traps (FAO, 2019). Distribution of the red porgy in the SWA is not homogeneous, with several distinct groups or stocks proposed based on parasites (Soares et al., 2018), otolith shape (Kikuchi et al., 2021), body shape (Porrini et al., 2015), and growth (García & Déspos, 2015).…”