• Korean Journal of Ichthyology
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• v.17 no.4
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• pp.248-254
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• 2005

Integumentary structure of the amberjack, Seriola dumerili, was examined by light and transmission electron microscopy. Integument of the amberjack consists of epidermal and dermal layers. The epidermal thickness is about $28.32{\mu}m$. The epidermal layer could be classified into superficial, intermediate, and basal layers by morphology and position of the supporting cells. Secretory cells of the epidermal layer were classified into mucous cells and club cells in the amberjack. Mucous cells contained acidic mucous and were alcian-blue positive with AB-PAS (pH 2.5) reaction. The club cells contained well-developed rough endoplasmic reticula and large central vacuole. Also, filament-rich cells were identified in the epidermal layer. The dermal layer consists mainly of collagenous fiber, and it contains fibrocytes and pigment cells. The cytoplasm of fibrocyte had a well-developed rough endoplasmic reticulum. The pigment cells contained electron-dense melanin granules.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.4
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• pp.269-275
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• 2003

In this paper, We examined auditory threshold and critical ratio of amberjack seriola dumerili, in the Jeju Island coastal waters, to find out hearing ability of the fish. The auditory threshold level, critical ratio and hearing index of amberjack were determinded by conditioning method using a sound coupled with electric shock in the condition of ambient noise or white noise in an experimental water tank. The audio-signals of pure tone and electric shock were from 80 HZ to 800 Hz and DC 7 V, respectively. Values for the critical ratios were calculated in terms of the masked thresholds using the noise projected to stable spectrum levels at all measurement frequencies of background noise. Masking noises were in the spectrum level range of 65 dB∼75 dB $(re 1{\mu}Pa\sqrt{Hz})$. The auditory thresholds of amberjack within the test the frequencies were most sensitive at 300HZ as 94.5 dB. The critical ratios of fishes ranged from 36.4 to 52.8 dB. The noise spectrum level that started masking was about 58∼72 dB within frequencies.