Work

A novel function for a carotenoid: astaxanthin used as a polarizer for visual signalling in a mantis shrimp

Year: 2012

Type: article

Abstract: Biological signals based on color patterns are well known, but some animals communicate by producing patterns of polarized light. Known biological polarizers are all based on physical interactions with light such as birefringence, differential reflection or scattering. We describe a novel biological polarizer in a marine crustacean based on linear dichroism of a carotenoid molecule. The red-colored, dichroic ketocarotenoid pigment astaxanthin is deposited in the antennal scale of a stomatopod crustacean, Odontodactylus scyllarus. Positive correlation between partial polarization and the presence of astaxanthin indicates that the antennal scale polarizes light with astaxanthin. Both the optical properties and the fine structure of the polarizationally active cuticle suggest that the dipole axes of the astaxanthin molecules are oriented nearly normal to the surface of the antennal scale. While dichroic retinoids are used as visual pigment chromophores to absorb and detect polarized light, this is the first demonstration of the use of a carotenoid to produce a polarizing signal. By using the intrinsic dichroism of the carotenoid molecule and orienting the molecule in tissue, nature has engineered a previously undescribed form of biological polarizer.

Source: Journal of Experimental Biology

DOI: 10.1242/jeb.066019

Authors: Tsyr-Huei Chiou, Allen R. Place, Roy L. Caldwell, N. Justin Marshall, Thomas W. Cronin

Institutions: The University of Queensland, University of Maryland, Baltimore County, University of Maryland, Baltimore, University of Maryland Biotechnology Institute, University of California, Berkeley

Language: English

Topic: Crustacean biology and ecology

Subfield: Ecology

Field: Environmental Science

Domain: Physical Sciences

Open Access status: bronze

Funders: National Science Foundation, Asian Office of Aerospace Research and Development, Air Force Office of Scientific Research

Award: Opsin Evolution in Stomatopod Crustaceans: Molecular Investigations of a Complex Visual System