Jaw malformation in cultured yellowtail kingfish (Seriola lalandi) larvae

Several jaw malformations are common in cultured finfish larvae. Hatchery‐reared yellowtail kingfish (Seriola lalandi) larvae were cleared and stained to examine cartilage and bone structure of the jaw. One malformation, characterised by a lowered hyoid arch, was present in kingfish larvae on days 4 and 8 post‐hatching, but not on day 12. A different malformation was present in larvae on day 16, typified by abnormal positioning of the lower jaw and hyoid arch, and breakage of the Meckel’ s cartilage. Evidence of jaw malformations as early as day 4 suggests that broodstock nutrition may be a factor in the jaw malformation of kingfish larvae, but other potential causes are environmental factors in culture and larval nutrition.