Geographical differences and their relationship with sea surface temperature of trace elements in the eye lenses of Jumbo flying squid (Dosidicus gigas)

Samples of Jumbo flying squid (Dosidicus gigas) were collected from Chinese squid jigging vessels in the high seas of Ecuador, Peru and Chile in the southeast Pacific Ocean in 2015 and 2017. The trace elements in the eye lenses of D. gigas were measured to study the geographical differences and their relationship with sea surface temperature. The results showed that elements such as Mg²⁵, Ni⁶⁰, Cu⁶³, Sr⁸⁸ and Ba¹³⁷ in the peripheral part of eye lenses of D. gigas in the high seas of Ecuador, Peru and Chile were significant difference, while there were no significant differences between each two sea areas in the elements of Na, Al, Si, P, Ca, Mn, Zn and Pb. Except for Sr⁸⁸, Ba¹³⁷, Fe⁵⁷ and Ni⁶⁰, which showed significantly linear negative correlations with SST (p<0.05), there were no significant correlations with SST in the other elements (p>0.05). Sr⁸⁸, Ba¹³⁷, Fe⁵⁷ and Ni⁶⁰ could be regarded as indicator elements of the ambient temperature of D. gigas, and Ba¹³⁷ could also be regarded as indicator element of the water depth and upwelling. Consequently, trace elements in eye lenses could be used to reconstruct the habitat environment of cephalopod.