title: Do you see what I see? Optical morphology and visual capability of 'disco' clams (Ctenoides ales).
abstract: The 'disco' clamCtenoides ales(Finlay, 1927) is a marine bivalve that has a unique, vivid flashing display that is a result of light scattering by silica nanospheres and rapid mantle movement. The eyes ofC. aleswere examined to determine their visual capabilities and whether the clams can see the flashing of conspecifics. Similar to the congenerC. scaber,C. alesexhibits an off-response (shadow reflex) and an on-response (light reflex). In field observations, a shadow caused a significant increase in flash rate from a mean of 3.9 Hz to 4.7 Hz (P=0.0016). In laboratory trials, a looming stimulus, which increased light intensity, caused a significant increase in flash rate from a median of 1.8 Hz to 2.2 Hz (P=0.0001). Morphological analysis of the eyes ofC. alesrevealed coarsely-packed photoreceptors lacking sophisticated structure, resulting in visual resolution that is likely too low to detect the flashing of conspecifics. As the eyes ofC. alesare incapable of perceiving conspecific flashing, it is likely that their vision is instead used to detect predators.
authors.affiliation: Department of Integrative Biology, University of California Berkeley, 3040 VLSB #3140, Berkeley, CA 94720, USA lindsey.dougherty@colorado.edu.|Department of Ecology and Evolutionary Biology, University of Colorado Boulder, 334 UCB, Boulder, CO 80309, USA.|Museum of Natural History, University of Colorado Boulder, 265 UCB, Boulder, CO 80302, USA.
authors.forename: Lindsey F
authors.identifier: http://orcid.org/0000-0002-9286-0651
authors.initials: LF
authors.lastname: Dougherty
authors.affiliation: Pathobiological Sciences Department School of Veterinary Medicine, University of Wisconsin, Madison, 2015 Linden Drive, Madison, WI 53706, USA.
authors.forename: Richard R
authors.initials: RR
authors.lastname: Dubielzig
authors.affiliation: Pathobiological Sciences Department School of Veterinary Medicine, University of Wisconsin, Madison, 2015 Linden Drive, Madison, WI 53706, USA.
authors.forename: Charles S
authors.initials: CS
authors.lastname: Schobert
authors.affiliation: Pathobiological Sciences Department School of Veterinary Medicine, University of Wisconsin, Madison, 2015 Linden Drive, Madison, WI 53706, USA.
authors.forename: Leandro B
authors.initials: LB
authors.lastname: Teixeira
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Colorado Boulder, 334 UCB, Boulder, CO 80309, USA.|Museum of Natural History, University of Colorado Boulder, 265 UCB, Boulder, CO 80302, USA.
authors.forename: Jingchun
authors.initials: J
authors.lastname: Li
keywords: Bivalve; Eyes; Flashing; Signal; Vision