Accession Number : ADA613381

Title :   Modular Organization of Dynamic Camouflage Body Patterning in Cuttlefish

Descriptive Note : Final rept. 28 Feb 2013-19 Sep 2014


Personal Author(s) : Chiao, Chuan-Chin

Full Text :

Report Date : 28 Nov 2014

Pagination or Media Count : 19

Abstract : Cephalopods (octopus, squid, and cuttlefish) can camouflage themselves against almost any background. Yet their ability to quickly alter their body patterns on different visual backgrounds has posed a research challenge: how they are able to pick the correct pattern amongst their repertoire. In cuttlefish, these studies and others have demonstrated that their ability to change skin coloration appropriately requires a visual system that can rapidly assess complex visual scenes and produce the motor output - the neutrally controlled body patterns - that achieves camouflage. The goal of this project was to study the neural basis of camouflage in cuttlefish, Sepia pharaonis, by combining behavioral assay with neurophysiological stimulation. In addition the oval squid Sepioteuthis lessoniana was used to make a parallel investigation and to broaden the scope of modular organization of body patterning. By applying electrical stimulation to systematically characterize the motor fields of command units in the optic lobe that control distinct body patterns in cuttlefish and oval squids, it was found that (1) the responsive areas are positively correlated with increasing voltages and depths of the electrode in the medulla of the optic lobe, and (2) the island-like clumps with a hierarchical organization in the medulla of the optic lobe are responsible for generating different body patterns. Although the original aim of using the dynamically changing visual background to study the spatiotemporal expression of body patterns was not successful, we discovered that sudden changing visual background can elicit threatening behaviors and may provide a new means of studying dynamic body patterning in the future. In conclusion, this project demonstrates that adaptive body coloration in cephalopods is based on the hierarchical principle of modular organization in the higher command center of the brain.


Subject Categories : Anatomy and Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE