“…To a lesser extent, other structures such as pelvic or dorsal spines (DeFaveri et al, ; Gambling & Reimchen, ; Reimchen, ) and gill covers (Mukhomediarov, ; Patimar et al, ; Yershov & Sukhotin, ) have also been used for aging G. aculeatus . Worryingly, studies conducted in other fish species have shown that there may be large discrepancies in age estimates depending on which structure was used for the analysis (Baudouin et al, ; Elzey et al, ; Hüssy et al, ; Khan et al, ; Sotola et al, ; van der Meulen et al, ; Watkins et al, ; Zhu et al, ; Zymonas & McMahon, ). Two recent G. aculeatus studies have analysed several structures (DeFaveri & Merilä, ; DeFaveri et al, ), but no study has formally compared the age estimates from different structures and their reliability in G. aculeatus .…”