Present address: Faculty of Marine Science and Fishery, Hasanuddin University, Makassar, 90245, Indonesia.
Visual acuity of Pacific Saury Cololabis saira for understanding capture process
Article first published online: 2 JUN 2008
© 2008 Japanese Society of Fisheries Science
Volume 74, Issue 3, pages 461–468, June 2008
How to Cite
HAJAR, M. A. I., INADA, H., HASOBE, M. and ARIMOTO, T. (2008), Visual acuity of Pacific Saury Cololabis saira for understanding capture process. Fisheries Science, 74: 461–468. doi: 10.1111/j.1444-2906.2008.01547.x
- Issue published online: 2 JUN 2008
- Article first published online: 2 JUN 2008
- Received 29 June 2007. Accepted 4 December 2007.
- behavioral response;
- capture process;
- cone density;
- maximum sighting distance;
- Pacific saury;
- retinal histology;
- visual acuity;
- visual axis
ABSTRACT: To understand the mechanism of the behavioral response in the capture process of how fish recognize fishing gear and then how they can avoid the gear, the visual acuity of Pacific saury Cololabis saira was investigated by histological examination of the retina of individuals in the size range of 75–365 mm fork length (FL). The contour map of cone density distribution shows that the highest cone density is located in the temporal area of the retina, which indicated the visual axis as the forward direction. The visual acuity (VA) depends both on the focal length of the lens and the number of cones in the retina. The lens diameter increased linearly from 1.40 to 4.73 mm with fish growth, while the cone density decreased gradually from 765 to 378 cells/0.01 mm2. Our results show that the visual acuity increases proportionately from 0.057 to 0.140 for individuals ranging in FL from 75 to 365 mm as expressed by the equation VA = 0.0065 × FL0.5271 (r2 = 0.9624).