Overall, we are interested in how cephalopods use their senses of vision and olfaction to carry out many of their primary behaviors in the field. For example, the functional morphology and neurobiology of the chromatophore system of cephalopods are studied on a variety of cephalopod species, and image analysis techniques are being developed to study crypsis and the mechanisms that enable cryptic body patterns to be neurally regulated by visual input. Various aspects of predation, antipredator defenses, and reproduction are conducted in field sites worldwide
Laboratory studies on the mechanisms and functions of polarized light sensitivity in cephalopods are underway. Olfactory sensing by Nautilus (which functions in food detection and location as well as mate choice) has been studied in the laboratory. Visual features that octopuses use for maze learning are also investigated. Lab experiments in large indoor seawater tanks are being conducted to determine how male squids, Loligo pealeii, use visual then contact chemical cues in egg capsules to initiate highly robust agonistic behavior.
iBioSeminar: Exploring Mechanisms of Visual Perception (51:00 min)
Publications on sensory ecology:
Mäthger, L.M., Shashar, N., & Hanlon, R.T. 2009. Do cephalopods communicate using polarized light reflections from their skin? Journal of Experimental Biology 212: 2133-2140. (Featured Commentary)(PDF)
Crook, R., Hanlon, R.T., & Basil, J. In press, 2009. Memory of visual and topographical features suggests spatial learning in the ancient cephalopod Nautilus. J. Comparative Psychology. (PDF)
Wilson, M., Hanlon, R.T., Tyack, P.L., & Madsen, P.T. 2007. Intense ultrasonic clicks from echolocating toothed whales do not elicit anti-predator responses or debilitate the squid Loligo pealeii. Biology Letters 3(3): 225-227.
Madsen, P.T., Wilson, M., Johnson, M., Hanlon, R.T., Bocconcelli, A., Aguilar Soto, N., & Tyack, P.T. 2007. Clicking for calamari: toothed whales can echolocate squid Loligo pealeii. Aquatic Biology 1: 141-150. (Feature Article)
Mäthger, L.M., Chiao, C-C., Barbosa, A., Buresch, K., Kaye, S., & Hanlon, R.T. 2007. Disruptive coloration elicited on controlled natural substrates in cuttlefish, Sepia officinalis J. Exp. Biol. 210: 2657-2666.
Mäthger, L.M., & Hanlon, R.T. 2007 Malleable skin coloration in cephalopods: selective reflectance, transmission and absorbance of light by chromatophores and iridophores. Cell and Tissue Research 329, 179186.
Wilson, M., Hanlon, R.T., Tyack, P.L., & Madsen, P.T. Intense ultrasonic clicks from echolocating toothed whales do not elicit anti-predator responses or debilitate the squid Loligo pealeii. Biology Letters
Mäthger, L.M., Barbosa, A., Miner, S., & Hanlon, R.T. 2006. Color blindness and contrast perception in cuttlefish (Sepia officinalis). Vision Research 46: 1746-1753. (PDF)
Mäthger, L.M., & Hanlon, R.T. 2006. Anatomical basis for camouflaged polarized light communication in squid. Biology Letters 2(4): 494-496. (PDF)
Saidel, W.M., Shashar, N., Schmolesky, M.T., & Hanlon, R.T. 2005. Discriminative responses of squid (Loligo pealeii) photoreceptors to polarized light. Comparative Biochemistry & Physiology A. 142 (3) 340-346. (PDF)
Boal, J.G., Shashar, N., Grable, M., Vaughan, K.H., Loew, E.R., & Hanlon, R.T. 2004. Behavioral evidence for intraspecific signals with achromatic and polarized light by cuttlefish (Mollusca: Cephalopoda). Behaviour 141: 837-861.
Hanlon, R.T., & Shashar, N. 2003. Aspects of the sensory ecology of cephalopods. In: Sensory Processing in the Aquatic Environment. Collin, S.P.; Marshall, N.J. (eds.). Springer-Verlag, New York, pp. 266-282.
King, A.J., Adamo, S.A., & Hanlon, R.T. 2003. Squid egg mops provide sensory cues for increased agonistic behavior between male squid. Anim. Behav. 66: 49-58.
Karson, M.A., Boal, J.G., Usook, S., & Hanlon, R.T. 2003. Experimental evidence for spatial learning in the cuttlefish, Sepia officinalis. J. Comp. Psychol. Vol. 117, No. 2, 149-155.
Buresch, K.C., Boal, J.G., Knowles, J., DeBose, J., Nichols, A., Erwin, A., Painter, S.D,; Nagle, G.T., & Hanlon, R.T. 2003. Contact chemosensory cues in egg bundles elicit male-male agonistic conflicts in the squid Loligo pealeii (Mollusca: Cephalopoda). J. Chem. Ecol. 29(3):547-560.
Basil, J.A., Lazenby, G.B., Nakanuku, L., & Hanlon, R.T. 2002. Female Nautilus are attracted to male conspecific odor. Bull. Mar. Sci. 70(1):217-225.
Shashar, N., Milbury, C.A., & Hanlon, R.T. 2002. Polarization vision in cephalopods: neuroanatomical and behavioral features that illustrate aspects of form and function. Mar. Freshwat. Behav. Physiol. 35(1-2):57-68.
Grable, M.M., Shashar, N., Gilles, N.L., Chiao, C-C., & Hanlon, R.T. 2002 Cuttlefish body patterns as a behavioral assay to determine polarization perception. Biol. Bull., 203: 232 234.
Chiao, C-C., & Hanlon, R.T. 2001. Cuttlefish camouflage: visual perception of size, contrast and number of white squares on artificial substrata initiates disruptive coloration. J. Exp. Biol. 204: 2119-2125.
Buresch, K.C., Boal, J.G., Knowles, J., DeBose, J., Nichols, A., Erwin, A., Painter, S.D., Nagle, G.T., & Hanlon, R.T. 2003 Contact chemosensory cues in egg bundles elicit male-male agonistic conflicts in the squid Loligo pealeii (Mollusca: Cephalopoda). J. Chem. Ecol., Vol 29, No. 3, March
Shashar, N., Hagan, R., Boal, J.G., & Hanlon, R.T. 2000. Cuttlefish use polarization sensitivity in predation on silvery fish. Vision Res. 40(1): 71-75.
Basil, J.A., Hanlon, R.T., Sheikh, S.I., & Atema, J. 2000. Three-dimensional odor tracking by Nautilus pompilius. J. Exp. Biol. 203(9): 1409-1414.
Boal, J.G., Wittenberg, K.M., & Hanlon, R.T. 2000. Observational learning does not explain improvement in predation tactics by cuttlefish (Mollusca: Cephalopoda). Behav. Processes 52:141-153.
King, A.J., Adamo, S.A., & Hanlon, R.T. 1999. Contact with squid egg capsules increases agonistic behavior in male squid (Loligo pealei). Biol. Bull. 197: 256.