Visual Function in Variable Environments: Mantis Shrimps as Models for the Sensory Biology of Color and Polarization Signaling

University Of Maryland Baltimore County, Baltimore MD

Investigators

Abstract

All visual tasks that animals perform in nature occur within the contexts of specific light environments. General scene properties usually are not as critical as stimulus signals sent by other animals. Thus, signaling systems must adapt both to vision of intended receivers and properties of the background. Furthermore, neither the background nor the organism has constant appearance because of continuous variations in the patterns of illumination falling upon them. These changing conditions, which at present are poorly understood, strongly influence the visual appearances and detection of signals. This project considers the interrelationships among vision, natural lighting, and visual signals used by a group of marine invertebrates, the mantis shrimps (stomatopod crustaceans). Mantis shrimp vision is highly evolved and specialized, capable of outstanding color and polarization vision, and these animals use signals constantly in agonistic and mating behavior. Most importantly, many mantis shrimp species live in diverse habitats where both their vision and their visual signals, including both color and polarized light, change in ways that seem to be adaptive to the varied environment. Using mantis shrimps as models, this project examines (1) how colors (i.e. spectral reflectances) and patterns of animals are adapted for enhanced conspicuousness, and (2) how visual systems of animals are specialized or tuned to detect signals. Comparisons are made among a diverse selection of closely related animals, all of which face identical sensory challenges: the formation and recognition of biological signals in the photic constraints of diversity of marine habitats. The research is a pioneering effort to learn how systems of vision and signaling operate in a diverse, carefully chosen set of extremely colorful marine species in the specific contexts of their natural illuminants and backgrounds. Its strengths lie in the selection of species and habitats and in the consideration of recent major advances in understanding the properties of signals and natural scenes. The proposed research will contribute significantly to the fields of sensory biology, visual ecology, and sensory evolution, and will be of added interest to engineers and scientists working in photonics, remote sensing, machine vision, and artificial systems of object detection and recognition. The project includes substantial student training, international collaborations, and has an impact on the general public scientific interest in animal vision, color, and communication.