Tagging the next generation: validation of trans-generational chemical tagging for an endangered fish

摘要

In this study we validated marking offspring through peritoneal injection of ripe females using two concentrations of strontium (strontium chloride hexahydrate). Larvae from treatments were monitored for condition morphometrics and tested for chemical mark incorporation in their otoliths via laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) to quantify the strontium concentration (Sr/Ca) and laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICPMS) to measure the strontium isotope ratios (87Sr:86Sr) of otoliths. Otolith strontium concentrations and strontium isotopes ratios were elevated in the high-concentration treatment, while the low-concentration and control treatments were not significantly different from each other. Larval size and eye diameter at hatch were similar among treatments; however, yolk and oil globule diameters were significantly reduced in the high-concentration treatment. Moreover, growth rates after 60 days post-hatch were significantly reduced in the high-concentration treatment relative to the low-concentration and control treatments, suggesting trans-generational tagging can have deleterious effects on offspring. Our study provides evidence for the efficacy of artificially marking offspring via injection of strontium into ripe females and could provide new tools for managing endangered fish populations; however, careful consideration of chemical concentrations and dosages may be required prior to its application in a fisheries management experiment.