• Korean Journal of Ichthyology
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• v.36 no.3
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• pp.230-239
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• 2024

This study was carried out the anatomical and histological investigation of the olfactory organ on a land-locked and an amphidromous Plecoglossus altivelis in Deokam-ri, Shinpyeong-myeon, Imsil-gun, Jeollabuk-do and Daeduk-ri, Gojeon-myeon, Hadong-gun, Gyeongsangnam-do, August, 2021, Korea. The external morphology of the two types of P. altivelis was indistinguishable, featuring a pair of the elliptical anterior nostrils, the semicircular posterior nostrils, and the nasal flaps on the snout. The olfactory organ consisted of 20 to 22 olfactory lamellae forming a rosette structure in the nasal chamber. The secondary folds appeared on the lamellae. The histological results were also uniform. The sensory epithelium was a continuous type, consisting of olfactory receptor neurons, supporting cells, basal cells, cilia, and an unidentified cell. The non-sensory epithelium found only in the terminal part of lamellae, consist of stratified epithelial cells, basal cells, and mucous cells. For the olfactory organ between a land-lock type and an amphidromous type, no difference was observed in external and histological structure between amphidromous and land-locked type. However, it is considered that P. altivelis has higher olfactory sensitivity than other anadromous fish due to more number of olfactory lamellae and the presence of the secondary folds.