My research interests lie in invertebrate behavior and ecology with much of my work centering on the behavioral ecology of stomatopod crustaceans, a group of tropical marine predators. The initial focus of this research was on how the evolution of potentially lethal weapons influenced stomatopod biology. These studies dealt mainly with communication and the function of aggression. More recent research has expanded to include the evolution of mating systems, interspecific communication, sensory ecology, prey selection, the biomechanics of the strike and larval biology. We are currently initiating studies on the genetic structure of stomatopod populations attempting to deduce the timing and pathways of dispersal. We have also used stomatopod populations as bio-indicators to assess the health of tropical coastal habitats. I have also become interested in the behavior of blue-ringed and other pygmy octopuses. We are currently studying the reproductive and aggressive behavior of several Indo-Pacific species. Much of my research is centered in the tropical Indo-Pacific including programs at Lizard Island, Moorea, and Indonesia.
Graduate students in my laboratory are not constrained to working on tropical marine invertebrates although an emphasis is maintained on invertebrate behavior and ecology. Students in my laboratory are currently studying octopus behavior, monogamy in stomatopods, remipede biology, and the function of inking in mid-water squid.
2008. Chiou, T. H, R. L. Caldwell, R. T. Hanlon and T. W. Cronin. Fine structure and optical properties of biological polarizers in crustaceans and cephalopods. Proceedings of SPIE, 6972: 1-10.
2008. Chiou, T. H, S. Kleinlogel, T. Cronin, R. Caldwell, B. Loeffler, A. Siddiqui, A. Goldizen and J. Marshall. Circular polarisation vision in a stomatopod crustacean. Current Biology 18: 429-434.
2008. Huffard, C. L., R. L. Caldwell and F. Boneka. Mating behavior of Abdopus aculeatus (d’Orbigny 1834) (Cephalopoda: Octopodidae) in the wild. Marine Biology 154:353-362.
2008 Meunier, F.J., M. V. Erdmann, Y. F. and R. L. Caldwell. Can the comparative study of the morphology and histology of the scales of Latimeria menadoensis and L. chalumnae (Sarcopterygii: Actinistia, Coelacanthidae) bring new insight on the taxonomy and the biogeography of recent coelacanthids? Geological Society, London, Special Publications; v. 295; p. 351-360 doi:10.1144/SP295.17
2008. Huffard, C.L., R..L. Caldwell , N. DeLoach, D. W. Gentry, P. Humann, B. MacDonald, B. Moore, R. Ross, T. Uno, S. Wong. Individually Unique Body Color Patterns in Octopus (Wunderpus photogenicus) Allow for Photoidentification. PLoS ONE 3:e3732 1-5.
2007. Patek, S.N., B. N. Nowroozi, J. E. Baio, R. L. Caldwell, A. P. Summers. Linkage mechanics and power amplification of the mantis shrimp’s raptorial strike. J. Exp. Biol. 210:3677-3688
2006. Fox. H. E. and R. L. Caldwell. Recovery from Blast Fishing on Coral Reefs: A Tale of Two Scales. Ecological Applications. 16:1631-1635.
2006. Cronin, T. W., R. L. Caldwell and J. Marshall. Learning in Stomatopod Crustaceans. Int. J. Comp. Psych. 19: 297-317
2006. Patek, S.N. and R.L. Caldwell, The stomatopod rumble: sound production in Hemisquilla californiensis. Mar. Freshwater Beh. Physiol. 39:99-111.
2005. Fox, H. E., P. J. Mous, J. S. Pet, A. H. Muljadi and R. L. Caldwell. Experimental assessment of coral reef rehabilitation following blast fishing. Conservation Biology 19:98-107.
2005. Patek, S.N. and R. L. Caldwell. Extreme impact and cavitation forces of a biological hammer: strike forces of the peacock mantis shrimp (Odontodactylus scyllarus). J. Exp. Biol. 208:3655-3664.
2005. Caldwell, R.L. An observation of inking behaviour protecting adult Octopus bocki from predation by Green Turtle (Chelonia mydas) hatchlings. Pacific Science 59:69-72.
2004. Patek, S.N., W.L. Korff and R.L. Caldwell, Mantis shrimp strike at high speeds with a saddle-shaped spring. Nature 428: 819-820.
2004. Mazel, C. H., T.W. Cronin, R.L. Caldwell and N.J. Marshall. Fluorescent enhancement of signaling in a mantis shrimp. Science 303:51.
2003. Fox, H. E., J. S. Pet, R. Dahuri, and R. L. Caldwell. Recovery in rubble fields: long-term impacts of blast fishing. Marine Pollution Bulletin 46:1024-1031.
2003. Cronin T. W., N. Shashar, R. L. Caldwell, A.G. Cheroske and T. H.Chiou. Polarization vision and its role in biological signaling. Integr. Comp. Biol. 43:549-558.
2001 Cronin, T.W., N.J. Marshall and R. L. Caldwell. Tunable colour vision in a mantis shrimp. Nature 411:547-548.
2000. Cheng, M.W. and R. L. Caldwell. Sex determination and mating in the blue-ringed octopus, Hapalochlaena lunulata. Anim. Behav. 60:27-33.
1999. Holder, M.T., M.V. Erdmann, T.P. Wilcox, R.L. Caldwell and D.M. Hillis. Two Living Species of Coelacanths? Proc. Nat. Acad. Science 96:12616-12620.