Taste Discrimination of Different Stimuli by an Anole (Anolis carolinensis) Alex Hoke Department of Biology, York College of Pennsylvania Introduction The taste transduction pathways have been studied in mammals and have also been studied thoroughly in fish, but not much in reptilian models. These pathways could be similar in reptiles to be able to distinguish taste (Brito Sanchez and Giurfa 2011, Finger 2008). Anoles are insectivorous, which means they will eat crickets, mealworms, spiders, and most other arthropods that are half the size of the anole’s head or less. Anoles will also eat spiders in the wild. These food items need to be moving for the anole to detect the prey item and attack it. Taste buds are present near the anterior and middle of the tongue with the greatest density at the anterior. The taste buds are thought to be located at these places to allow the anole to detect an adverse taste before it gets into the digestive tract and causes harm to the individual. It was also found that the vomeronasal organ and olfactory bulbs play no role in discrimination of prey items (Schwenk 1985, Stranger-Hall et al 2001). Anoles seem to be able to discriminate between sweet tastes and bitter tastes. Stranger-Hall et al (2001) found that the anoles completely rejected the bitter stimulus and did not eat the prey item. The sweet stimulus was found to be eaten readily by the anoles with no adverse effects and in some cases, increased the occurrence of the number of crickets eaten. Batog (2009) also found that anoles will take longer to eat a cricket coated in citric acid solution and will have an adverse reaction to the stimuli. Methods Questions Asked Can Anolis carilonensis taste capsaicin or salty substances? Is there a way to quantify a positive or negative reaction to a taste stimulus in Anolis carolinensis? Testing Apparatus Heat lamp Perching Branch Substrate(vermiculite) Made a 4 day starvation period before each test day Allowed 3 weeks for anoles to acclimate Obtained male (n=7) and female (n=6) green anoles Neutral n=13 Polycose n=13 Quinine hydrochloride n= 13 Capsaicin n=13 Salt n=13 Crickets were uncoated (neutral) or coated with 1 of 4 stimuli Recorded reaction, licks, headshakes, and time to consume Results Conclusions 1. Anoles seem to be able to taste salty substances while not able to taste capsaicin. 2.There seems to be no definitive way to quantify rejection reactions or positive reactions. References Batog, A Behavioral responses of the green anole (Anolis carlinensis) to citric acid gustation. York College Senior Thesis. Brito Sanchez, G. and Giurfa, M A comparative analysis of neural taste processing in animals. Philosophical Transactions of the Royal Society Biological Sciences. 366(1574): Finger, F. E Sorting food from stones: the vagal taste system in goldfish, Carassius auratus. Journal of Comparative Physiology. 194(2): Schwenk, K Occurrence, distribution and functional significance of taste buds in lizards. Copeia. 1: Stranger-Hall, K. F., Zelmer, D. A., Bergren, C., and Burns, S. A Taste discrimination in a lizard (Anolis carolinensis, Polychrotidae). Copeia. 2: Acknowledgements I would like to thank the York college biology department for allowing me to conduct my research. I would also like to thank Dr. Rehnberg and Dr. Hagerty for helping me with my design and the safety of my animals. Observer ile:Anolis_carolinensis_aggression.jpg overview