Differences in olfactory system between wild and cultured black sea bream, Acanthopagrus schlegeli (Sparidae, Teleostei)

Observation of black sea bream artificially propagated and reared in mariculture facility revealed that ∼40% of fish possess a deformed single olfactory nasal opening as compared with a normal fish with an anterior and a posterior nares at both olfactory organs. Of these deformed fish, their densities of microvillous olfactory receptor neurons are remarkably reduced (P<0.001) when compared with wild fish. Olfactory sensitivity in both fish stocks are similar when tested with amino acids. However, the concentration-response curves and response effectiveness to amino acids in wild and cultured fish showed some variations. Differences in olfactory-mediated behaviors in wild and cultured sea breams are discussed.