Trace elements in statoliths of Sthenoteuthis oualaniensis in Nansha Islands of the South China Sea

In order to explore the trace element composition characteristics of Sthenoteuthis oualaniensis, the composition and distribution of trace elements in 17 statoliths of S. oualaniensis collected in the Nansha islands waters of the South China Sea during March to May by light falling-net vessels in 2017 were analyzed with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The results showed that the statolith of S. oualaniensis contained 56 elements, and calcium (Ca), strontium (Sr), sodium (Na), phosphorus (P), silicon (Si), potassium (K), magnesium (Mg), iron (Fe), barium (Ba) and boron (B) were the ten most abundant elements. The analysis of variance (ANOVA) showed that there was no significant difference in the distribution of all ten most abundant elements between different sexes and hatching groups. There were significant differences in the contents of Ca, Sr, Na, P, Mg, Ba and B, but no significant difference in the contents of Si, K and Fe between different areas of the statolith. The study showed that the trace element composition of S. oualaniensis varied in different habitats and in different growth stages, but the trace element composition of S. oualaniensis of different sexes was basically the same, which further confirmed the feasibility of using trace element distribution characteristics to identify cephalopod populations and study migratory routes.