Inter-annual variability in otolith chemistry of catfish Genidens barbus from South-western Atlantic estuaries

Abstract

The catfish Genidens barbus is a commercial species from South America. The aim of the present study was to examine the inter-annual variability in estuary-specific chemical signatures of otolith cores (Ba:Ca, Mg:Ca, Mn:Ca, Sr:Ca and Zn:Ca ratios) for three estuaries from Argentina and Brazil where adults were collected over multiple years. Secondarily, we evaluated whether the percentages of classification of individuals to their natal origin place are affected by the grouping of several cohorts. Most element:Ca ratios were not significantly different among year cohorts. Results from PERMANOVA revealed significant differences in the multi-element signatures of the otolith core between cohorts for the Plata River estuary (PR) (P = 0.006) and the Patos Lagoon (PL) (P = 0.03), while no significant differences (P = 0.9) were found for Paranaguá Bay (PB). The percentages of spatial classification (discriminant function analyses) decreased to between 15.5 and 25% for PR and PL when cohorts were grouped. This work makes it clear that the temporal variation in the chemical signature of the adult catfish otolith core can greatly affect the percentages of spatial classification.

Systematic Review of Fish Ecology and Anthropogenic Impacts in South American Estuaries: Setting Priorities for Ecosystem Conservation

“…Description of growth parameters using length and age data (Velasco et al, 2007) and the use of estuarine carbon sources revealed by isotope analyses (Pereyra et al, 2016) report biological aspects for the species. Ecological aspects were revealed by otolith microchemistry and patterns of estuarine uses (Avigliano et al, 2015), inter-annual variability (Avigliano et al, 2017a), freshwater residence times (Avigliano et al, 2017b), nursery grounds and connectivity (Avigliano et al, 2016) are available for the species.…”

Fin spine metals by LA-ICP-MS as a method for fish stock discrimination of Genidens barbus in anthropized estuaries

“…Annuli were counted in transmitted light using a stereomicroscope (Leica® EZ4-HD, Singapore) at 40X magnification while otoliths were immersed in ultrapure water. In terms of age criteria, the protocol previously reported by Avigliano et al (2017a) for G. barbus was used to ageing the specimens. Mean age ± SD and range (in years) were 7.3 ± 1.17 (6-10) for PEC, 9.5 ± 0.97 (7-10) for PRD, for NR.…”

Temporal stability in the otolith Sr:Ca ratio of the yellow croaker, Larimichthys polyactis (Actinopterygii, Perciformes, Sciaenidae), from the southern Yellow Sea

“…There has been considerable research on the geographical variation of natal geochemical signatures, but limited studies have examined the temporal stability of otolith chemistry. Studies that examined temporal variation in otolith chemical composition found substantial variations within (Thorrold and Shuttleworth 2000;Reis-Santos et al 2012) and among years (Campana et al 2000;Gillanders 2002;Walther and Thorrold 2009;Pruell et al 2012), which could lead to misinterpretation of spatial variability in otolith signatures (Reis-Santos et al 2012;Avigliano et al 2018). For instance, in Platichthys flesus (Linnaeus, 1758) and Dicentrarchus labrax (Linnaeus, 1758), collected from several estuaries along the Portuguese coast in two years and three seasons within a year, significant differences were observed in the majority of otolith elements among estuaries and sampling times, which were likely to be a reflection of the observed variability in environmental conditions, incorporating seasonal variation, which resulted in an 11% increase in the correct classification of individual estuaries (Reis-Santos et al 2012).…”

“…There was some overlap in elemental fingerprints among years for different estuaries for juvenile snapper Pagrus auratus (Forster, 1801), which was likely to have consequences in the assignment of adult fish to recruitment estuaries, especially if juvenile fish were collected from different estuaries in different years and adult fish were not assigned to recruitment estuaries using elemental fingerprints from the year class of recruits in which they were juveniles (Gillanders 2002). Furthermore, the long-term stability of otolith chemical signatures has been less frequently investigated (Avigliano et al 2018), suggesting that chemical signatures may serve only as shortterm natural tags (1-3 y) (Rooker et al 2001;Walther and Thorrold 2009;Pruell et al 2012).…”