Determination of visual acuity and visual axis of brown-marbled grouper, epinephelus fuscoguttatus to develop a demand feeding system

Han Tan, Nai and Mukai, Yukinori and Firdaus, Rian Freddie (2013) Determination of visual acuity and visual axis of brown-marbled grouper, epinephelus fuscoguttatus to develop a demand feeding system. Malaysian Journal of Science, 32 (1). pp. 24-28. ISSN 1394-3065

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Abstract

The visual acuity and visual axis of juvenile brown-marbled grouper, Epinephelus fuscoguttatus were determined to get the understanding of their vision in order to develop a demand feeding system. Three juveniles were anaesthetised with MS222 and fixed in Bouin’s solution. The left retina of each juvenile was cut into nine regions – the dorso-nasal (DN), dorsal (D), dorso-temporal (DT), nasal (N), bottom (B), temporal (T), ventro-nasal (VN), ventral (V), and ventro-temporal (VT). The specimens were embedded in paraffin, cut into 6 μm thick tangential sections, and stained with haematoxylin-eosin. The density of cone cells (0.01 mm2) in each region was counted in the stained sections. Visual acuity was calculated using cone cell densities and lens diameter. The highest cone cell densities of each of the juveniles were 359 (bottom, B), 394 (temporal, T), and 380 cells/0.01 mm2 (temporal, T), respectively. The estimated visual acuities were 0.068-0.081 in those regions, respectively. These results showed that the visual axis of brown-marbled grouper juveniles was forward. Therefore, the position of the target switch of demand feeding system was set at 2 cm below the water surface.

Item Type:	Article (Journal)
Additional Information:	6616/33677
Uncontrolled Keywords:	Brown-marbled grouper;Epinephelus fuscoguttatus ; visual acuity; visual axis; demand feeding system )
Subjects:	S Agriculture > SH Aquaculture. Fisheries. Angling
Kulliyyahs/Centres/Divisions/Institutes (Can select more than one option. Press CONTROL button):	Kulliyyah of Science > Department of Biotechnology
Depositing User:	Dr. Yukinori Mukai
Date Deposited:	24 Dec 2013 14:21
Last Modified:	24 Dec 2013 14:21
URI:	http://irep.iium.edu.my/id/eprint/33677

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