Elemental composition of illicia and otoliths and their potential application to age validation in white anglerfish (Lophius piscatorius linnaeus, 1758)

Abstract

The incorporation of trace elements into the calcified structures of fish can vary seasonally. Interpretation of these seasonal signals can provide information about fish age. This approach offers great promise for objectively estimating age and corroborating other methods of age estimation for fish stock assessment. This study investigated seasonal variation in trace element composition of otoliths and illicia from white anglerfish (Lophius piscatorius L.), a species that is very difficult to age using visual interpretation of growth bands in their calcified structures. A suite of trace elements (Na, Mg, Zn, Sr, Ba in illicia and Na, Mg, K, Sr, Ba in otoliths) was measured with LA-ICPMS using discrete ablations and continuous line scans. A method is presented to obtain reliable measurements of microchemical composition from illicia. Variation in elemental concentrations at the edge of the illicium was primarily related to fish length and no differences were detected between fish collected at different times of the year. In otoliths, Sr concentrations at the edge (0-100 μm) were highest in anglerfish collected during wintertime (quarter 1). Seasonal differences in Sr were statistically significant but small; a larger proportion of the explained variance was attributed to length and individual variability. Nonetheless, the seasonal pattern was consistently detected across all size classes, indicating that the analysis of cycles in otolith Sr could potentially provide a tool to support age estimation in white anglerfish.

Reading the biomineralized book of life: expanding otolith biogeochemical research and applications for fisheries and ecosystem-based management

“…Minima often correlate with visually identified translucent winter growth zones (Friedrich & Halden 2010;Halden et al 2000;Halden & Friedrich 2008;Hüssy et al 2016b;Limburg & Elfman 2010) or occur during the coldest months of the year (Hüssy et al 2021a). Seasonal differences have also been described in Sr (Brophy et al 2021;Siskey et al 2016;Tzeng et al 1999), though this element is often considered a proxy for environmental salinity.…”

Using seasonal oscillations in fin ray microchemistry to chemically age Lake Sturgeon

“…2020; Brophy et al. 2021; Frey 2022). This technique has been referred to as “chemical aging” and involves interpretation of areas of high and low elemental concentrations (Hüssy et al.…”

“…Elemental concentrations have been observed to oscillate seasonally in various fish species, with (1) high elemental concentrations occurring within the broader sections of annuli associated with high growth during warm summer months and (2) minimum concentrations present within the narrow winter zones of the structure (e.g., Arctic Char Salvelinus alpinus: Halden et al 2000;Brown Trout Salmo trutta and Atlantic Salmon Salmo salar: Limburg et al 2001; Lake Trout Salvelinus namaycush: Halden and Friedrich 2008; Northern Pike Esox lucius : Friedrich and Halden 2010). Using this information, the microchemistry within hard structures has been utilized to assist in aging fish that are difficult to age by traditional methods (Hüssy et al 2015(Hüssy et al , 2021Siskey et al 2016; Executive Agency for Small and Medium-sized Enterprises 2020; Heimbrand et al 2020;Brophy et al 2021;Frey 2022). This technique has been referred to as "chemical aging" and involves interpretation of areas of high and low elemental concentrations (Hüssy et al 2015).…”

“…2015, 2021; Siskey et al. 2016; Executive Agency for Small and Medium‐sized Enterprises 2020; Heimbrand et al. 2020; Brophy et al.…”