title: Investigating photoreceptor densities, potential visual acuity, and cone mosaics of shallow water, temperate fish species.
abstract: The eye is an important sense organ for teleost species but can vary greatly depending on the adaption to the habitat, environment during ontogeny and developmental stage of the fish. The eye and retinal morphology of eight commonly caught trawl bycatch species were described: Lepidotrigla mulhalli; Lophonectes gallus; Platycephalus bassensis; Sillago flindersi; Neoplatycephalus richardsoni; Thamnaconus degeni; Parequula melbournensis; and Trachurus declivis. The cone densities ranged from 38 cones per 0.01 mm(2) for S. flindersi to 235 cones per 0.01 mm(2) for P. melbournensis. The rod densities ranged from 22800 cells per 0.01 mm(2) for L. mulhalli to 76634 cells per 0.01 mm(2) for T. declivis and potential visual acuity (based on anatomical measures) ranged from 0.08 in L. gallus to 0.31 in P. melbournensis. Higher rod densities were correlated with maximum habitat depths. Six species had the regular pattern of four double cones arranged around a single cone in the photoreceptor mosaic, while T. declivis had only rows of double cones. P. melbournensis had the greatest potential ability for detecting fine detail based on eye anatomy. The potential visual acuity estimates and rod densities can be applied to suggest the relative detection ability of different species in a commercial fishing context, since vision is a critical sense in an illuminated environment for perceiving an oncoming trawl.
authors: Northern Hub, Institute for Marine and Antarctic Studies, University of Tasmania, Locked Bag 1370, Launceston, TAS 7250, Australia. Electronic address: darcieh@amc.edu.au.
authors: D E
authors: DE
authors: Hunt
authors: Northern Hub, Institute for Marine and Antarctic Studies, University of Tasmania, Locked Bag 1370, Launceston, TAS 7250, Australia.
authors: N J F
authors: NJ
authors: Rawlinson
authors: University College London, Torrington Place, London WC1E 7JE, United Kingdom.
authors: G A
authors: GA
authors: Thomas
authors: Fisheries and Aquaculture Centre, Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 49, Hobart, TAS 7001, Australia; University of the Sunshine Coast, Locked Bag 4, Maroochydore DC, Queensland 4558, Australia.
authors: J M
authors: JM
authors: Cobcroft
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002452:Cell Count; D005123:Eye / Q000033:anatomy & histology; D005399:Fishes / Q000502:physiology*; D007908:Lens, Crystalline / Q000033:anatomy & histology; D017949:Retinal Cone Photoreceptor Cells / Q000166:cytology*; D017948:Retinal Rod Photoreceptor Cells / Q000166:cytology*; D014785:Vision, Ocular; D014792:Visual Acuity / Q000502:physiology*
keywords: Cone density; Cone mosaic; Minimum separable angle; Potential visual acuity; Rod density