Vaterite Sagittal Otoliths in Hatchery-Reared Juvenile Red Drums

Aberrant otoliths, although uncommon, have been reported in many fish species. We examined sagittae, lapilli, and asterisci from 1,140 wild and 1,723 hatchery-reared juvenile red drums (Sciaenops ocellatus). Aberrant sagittae were found in 20 hatchery-reared fish. These otoliths, which appeared to be formed from a conglomeration of small spheres, were composed of the vaterite polymorph of calcium carbonate instead of the aragonite polymorph normally found in sagittae. No internal ring structure was present; however, gross external morphological features were similar to normal sagittae. Affected red drums had one normal sagitta, and all lapilli and asterisci were normal. No abnormal sagittae were found in wild fish.