The present study examined otolith characteristics at hatch in the lesser sandeel, Ammodytes marinus and assessed the efficacy of using these characteristics to reflect larval characteristics important to early survivorship in this species. Otoliths were examined from hatched larvae incubated at different temperatures representative of that experienced in the wild. Firstly, daily periodicity of otolith increment deposition was validated, and check formation confirmed to be synchronous with hatching. Secondly, relationships between otolith and body size at hatch, embryonic duration and incubation temperature were examined. Embryonic duration appeared the strongest determinant of otolith size at hatch, with only a weak effect of fish size at hatch. Given the inherent difficulties in accounting for variations in embryonic duration and incubation temperature in the field, otolith size at hatch is unlikely to be of general use as a proxy for larval characteristics in species, like sandeel, with an extended embryonic period and subject to varying temperature. © 2020