Dr. Ralph Saporito

Research Interests

My research is broadly focused on understanding the ecology and evolution of chemical defenses (toxins) and warning coloration in animals. Most of my research involves the study of brightly colored poison frogs from tropical rainforests, and the alkaloid toxins they acquire from a diet of mites, ants, and millipedes. I am particularly interested in how poison frogs use alkaloids to defend themselves against predators and pathogens, as well as their use of bright coloration and behavior as a warning signal of their toxicity. My research is highly integrative, involves field-work in the tropics and lab experiments at John Carroll, and incorporates aspects of behavior, physiology, natural history, and frog/arthropod chemistry.

Education

Ph.D. in Biological Sciences, Florida International University (2007)
B.S. in Biological Sciences with Honors, Minor in Chemistry (2000)

Courses Taught

• Principles of Biology 3 (BL1700)
• Human Anatomy & Physiology 1 (BL2310)
• Human Anatomy & Physiology 1 Lab (BL2315L)
• Human Anatomy & Physiology 2 (BL2320)
• Human Anatomy & Physiology 2 Lab (BL2325L)
• Tropical Field Biology (BL4060)
• Master’s Thesis Proposal (BL5980)

Publications

1. Jeckel, A.M.^, Saporito, S.K., Antoniazzi, M.M., Jared, C., Matsumura, K., Nishikawa, K., Morimoto, Y., Saporito, R.A., Grant, T. (2025) Experimental evidence supports gradual evolution of alkaloid sequestration in poison frogs. Proceedings of the Royal Society B: Biological Sciences, in review (after revision).
2. Minder, B.^, Brunetti, A.E., Mendonça, J.N., Moreira da Silva, R., Saporito, R.A., Grant, T. and Lopes, NP (2025) The role of different organs in the hydroxylation of a pumiliotoxin alkaloid in the poison frog Adelphobates galactonotus. Toxicon, in review.
3. Sidloski, M.C.* and Saporito R.A. (2025) Mastigodryas melanolomus (Salmon-bellied Racer). Herpetotheres cachinnans (Laughing Falcon). Predator-Prey Interactions. Herpetological Review, in press.
4. Márquez, R., Machado, D.J., Nouri, R., Janies, D., Saporito, R.A., Kronforst, M., Grant, T. (2025) A draft genome assembly for the dart-poison frog Phyllobates terribilis. Gigabyte, published online 20 June 2025 (awaiting issue assignment).
5. Porras-Brenes, K.**, Church, G.*, and Saporito, R.A. (2024) No evidence of quantitative honest signaling in aposematic traits of the green and black dendrobatid frog Dendrobates auratus in Costa Rica. Current Zoology, published online 30 December 2024 (awaiting issue assignment).
6. Albuquerque-Pinna, J.^, Jeckel, A.M.^, Nakamura, D.Y.M, Bernarde, P.S., Kocheff, S.*, Saporito, R.A., and Grant, T. (2024) Defensive alkaloid variation and palatability in sympatric poison frogs. Chemoecology, 34: 83-94.
7. Porras-Brenes, K.**, Church, G.*, Clark, E.*, Fellenstein, A.*, and Saporito, R.A. (2023) Stiff-legged behaviour in the green and black poison frog Dendrobates auratus in response to simulated predation. Herpetological Bulletin, 166: 43-44.
8. Sague, M., Dudaitis, V.*, Plumert, L., Umbers, K.D.L., Saporito, R.A., Lawrence, J.P. (2023) Alkaloid-based chemical defenses and diet in six species of Australian poison frogs in the genus Pseudophryne. Evolutionary Ecology, published Oct. 19, awaiting volume.
9. Waters, K.R.**, Dugas, M.B., Grant, T., and Saporito, R.A. (2023) The ability to sequester epibatidine is widespread among poison frogs. Evolutionary Ecology, published Sep. 27, awaiting volume.
10. Dugas, M.B., Brooks, O.L.**, Saporito, R.A., and Cossio, R. (2023) Adult poison frogs can capture and consume tadpoles. Evolutionary Ecology 38: 69-75.
11. Kizirian, D., Manual Padial, J., Povelikin, N., Overcast, I., Donnelly, M.A., Quitian, M., Segall, M., Kuhn, A., Campbell, G., and Saporito, R.A. (2023) Feedback in Batesian mimicry systems. Biological Journal of the Linnean Society 139: 326-335.
12. Lawrence, J.P., Rojas, B., Blanchette, A.**, Saporito, R.A., Mappes, J., Fouquet, A., and Noonan, B.P. (2023) Linking predator responses to alkaloid variability in poison frogs. Journal of Chemical Ecology 49: 195-204.
13. Brooks, O.L.**, James, J.J., and Saporito, R.A. (2023) Maternal chemical defenses predict offspring defenses in a dendrobatid poison frog. Oecologia 201: 385-396.
14. Villanueva, E.D.**, Brooks, O.L.**, Bolton, S.K.**, Savastano, S., Schulte, L.M., and Saporito, R.A. (2022) Maternal provisioning of alkaloid defenses are present in obligate but not facultative egg feeding dendrobatids. Journal of Chemical Ecology 48: 900-909.
15. Jones, T.H., Harrison, D.P., Menegatti, C., Mevers, E., Knott, K., Marek, P., Hennen, D.A., Kasson, M.T., Macias, A.M., Lovett, B., and Saporito, R.A. (2022) Deoxybuzonamine Isomers from the Millipede Brachycybe lecontii (Platydesmida: Andrognathidae). Journal of Natural Products 85: 1134–1140.
16. Jeckel, A.M.^, Bolton, S.K.**, Waters, K.R.**, Antoniazzi, M.M., Jared, C., Matsumura, K., Nishikawa, K., Morimoto, Y., Grant, T., and Saporito, R.A. (2022) Dose-dependent alkaloid sequestration and N-methylation of decahydroquinoline in poison frogs. Journal of Experimental Zoology 337: 537-546.
17. Okada, T., Wu, N., Takashima, K., Ishimura, J., Morita, H., Ito, T., Kodama, T., Yamasaki, Y., Akanuma, S., Kubo, Y., Hosoya, K., Tsuneki, H., Wada, T., Sasaoka, T., Shimizu, T., Sakai, H., Tanabe, G., Dwoskin, L.P., Hussain, S.R., Saporito, R.A., and Toyooka, N. (2021) Total synthesis of decahydroquinoline poison frog alkaloids ent-cis-195A and cis-211A. Molecules 26: 7529-7544.
18. Davison, I.^, Saporito, R.A., Schulte, L.M.^, and Summers, K. (2021) Piperidine alkaloids from fire ants are not sequestered by the green and black poison frog (Dendrobates auratus). Chemoecology 31: 391-396.
19. Hassler, F.M., Harrison, D.P., Jones, T.H., Richart, C.H., and Saporito, R.A. (2020) Gosodesmine, a 7-substituted hexahydroindolizidine from the millipede Gosodesmus claremontus. Journal of Natural Products 83: 2764-2768.
20. Basham, E.W.^, Saporito, R.A., González-Pinzón, M., Romero-Marcucci, A., and Scheffers, B.R. (2020) Chemical defenses shift with the seasonal vertical migration of a Panamanian poison frog. Biotropica 53: 28-37.
21. Jeckel, A.M.^, Matsumura, K., Nishikawa, K., Morimoto, Y., Saporito, R.A., Grant, T., and Ifa, D.R. (2020) Use of whole-body cryosectioning and desorption electro spray ionization mass spectrometry imaging (DESI-MSI) to visualize alkaloid distribution in poison frogs. Journal of Mass Spectrometry 55: e4520-e4525.
22. Savastano, N.*, Lutz, K.*, Britton, A.*, and Saporito, R.A. (2020) Defensive behaviour exhibited by the yellow-striped poison frog (Dendrobates truncatus) in response to simulated predation. The Herpetological Bulletin 151: 41-42.
23. Brooks, O.L.** and Saporito, R.A. (2019) For poison frogs, bitter is better. Special Issue: Venoms and Toxins. The Biochemist, Volume 41, Issue 6. Portland Press.
24. Jeckel, A.M.^, Kocheff, S.*, Saporito, R.A., and Grant, T. (2019) Geographically separated orange and blue populations of the Amazonian poison frog Adelphobates galactonotus (Anura, Dendrobatidae) do not differ in alkaloid composition or palatability. Chemoecology 29: 225-234.
25. Lawrence, J.P.^, Rojas, B., Fouquet, A., Mappes, J., Blanchette, A.**, Saporito, R.A., Bosque, R.J., Courtois, E.A., and Noonan, B. (2019) Weak warning signals can exist in the absence of gene flow. Proceedings of the National Academy of Sciences of the United States of America 116: 19037-19045.
26. Sanchez, E., Rodríguez, A., Grau, J., Lötters, S., Künzel, S., Saporito, R.A., Ringler, E., Schulz, S., Wollberg Valero, K.C., and Vences, M. (2019) Transcriptomic signatures of experimental alkaloid consumption in a poison frog. Genes 10: 733-746.
27. Thompson, M.E.^, Saporito, R.A., Ruiz-Valderrama, D.H., Medina-Rangel, G.F., and Donnelly, M.A. (2019) A field-based survey of fluorescence in tropical tree frogs using an LED UV-B flashlight. Herpetology Notes 12: 987-990.
28. Saporito, R.A., Russell, M.W.*, Richards-Zawacki, C.L., and Dugas, M.B. (2019) Experimental evidence for maternal provisioning of alkaloid defenses in a dendrobatid frog. Toxicon 161: 40-43.
29. Okada, T., Yamamoto, T., Kawasaki, M., Saporito, R.A., and Toyooka, N. (2018) Synthesis of 8-deoxypumiliotoxin 193H and 9-deoxypumiliotoxin 207O. Tetrahedron Letters 59: 3797-3800.
30. DeMarchi, J.**, Britton, A.*, O'Donnell, K.*, and Saporito, R.A. (2018) Behavioural preference for low levels of UV-B radiation in two neotropical frog species from Costa Rica. Journal of Tropical Ecology 34: 336-340.
31. Saporito, R.A. and Grant, T. (2018) Comment on Amézquita et al. (2018) "Conspicuousness, color resemblance, and toxicity in geographically diverging mimicry: The pan-Amazonian frog Allobates femoralis." Evolution 72: 1009-1014.
32. Stuckert, A.M.^, Saporito, R.A., and Summers, K. (2018) An empirical test indicates only qualitative honest aposematic signaling within a population of vertebrates. Journal of Herpetology 52: 201-208.
33. Hovey, K.J.**, Seiter, E.M.*, Johnson, E.E., and Saporito, R.A. (2018) Sequestered alkaloid defenses in the dendrobatid poison frog Oophaga pumilio provide variable protection from microbial pathogens. Journal of Chemical Ecology 44: 312-345.
34. Jones, T.H., Guthrie, D.M., Hogan, C.T., Robinson, D.J., Mesibov, R., Shear, W.A., Spande, T.F., and Saporito, R.A. (2018) The chemistry of some dalodesmidean millipedes from Tasmania (Diplopoda, Polydesmida). Journal of Natural Products 81: 171-177.
35. Bulbert, M.W.^, White, T.E., Saporito, R.A., and Kraus, F. (2018) Ontogenetic colour change in Oreophryne ezra (Anura: Microhylidae) reflects an unusual shift from conspicuousness to crypsis but not in toxicity. Biological Journal of the Linnean Society 123: 12-20.
36. Bolton, S.K.**, Dickerson, K., and Saporito, R.A. (2017) Variable alkaloid defense in the dendrobatid poison frog (Oophaga pumilio) are perceived as differences in palatability to arthropods. Journal of Chemical Ecology 43: 273-289.
37. Von Byern, J., Grunwald, I., Kosok, M., Saporito, R.A., Dicke, U., Wetjen, O., Thiel, K., Borcherding, K., Kowalik, T., Marchetti-Deschmann, M. (2017) Chemical characterization of the adhesive secretions of the salamander Plethodon shermani (Caudata, Plethodontidae). Scientific Reports 7:6647 1-13.
38. Blanchette, A.**, Becza, N.*, and Saporito, R.A. (2017) Escape behaviour of aposematic (Oophaga pumilio) and cryptic (Craugastor sp.) frogs in response to simulated predator approach. Journal of Tropical Ecology 33: 165-169.
39. Solano, M., Vega, A., and Saporito, R.A. (2017) Phyllobates lugubris (Lovely Poison Frog). Predation by Coniophanes fissidens (Yellowbelly Snake). Herpetological Review 48: 831.
40. Blanchette, A.** and Saporito, R.A. (2017) Deimatic behaviour exhibited by the green and black poison frog (Dendrobates auratus) after exposure from underneath a cover object. Herpetological Bulletin 140: 23-24.
41. Gade, M.R.**, Hill, M., and Saporito, R.A. (2016) Color assortative mating in a mainland population of the poison frog Oophaga pumilio. Ethology 122: 1-8.
42. Schulte, L.M.^, Saporito, R.A., Davison, I.^, and Summers, K. (2016) The palatability of poison frogs: Do alkaloids make the difference? Biotropica 49: 23-26.
43. Crothers, L.^, Saporito, R.A., Yeager, J.^, Lynch, K., Friesen, C., Richards-Zawacki, C.L., McGraw, K., and Cummings, M. (2016) Warning signal properties covary with toxicity but not testosterone or aggregate carotenoids in a poison frog. Evolutionary Ecology 30: 601-621.
44. Jones, A.W. and Saporito, R.A. (2016) Bird mobbing of Boa constrictor in a lowland tropical rainforest of Costa Rica. Herpetological Bulletin 137: 41.
45. Davis, L.R., Klonoski, K., Rutschow, H.L., Van Wijk, K., Sun, Q., Haribal, M.M., Saporito, R.A., Vega, A., Rosenbaum, E.B., Zamudio, K.R., and Robertson, J.M. (2016) Host defense skin peptides vary with color pattern in the highly polymorphic red-eyed treefrog. Frontiers in Ecology & Evolution 4: 97-111.
46. Murray, E.M., Bolton, S.K.**, Berg, T., and Saporito, R.A. (2016) Arthropod predation in a dendrobatid poison frog: Does frog life stage matter? Zoology 119: 169-174. 47. Blanchette, A. ** and Saporito, R.A. (2016) Defensive behaviour exhibited by the green and black poison frog (Dendrobates auratus) in response to simulated predation. Herpetological Bulletin 136: 39.
48. Hantak, M.M.**, Paluh, D.J*, and Saporito, R.A. (2016) Bufadienolide and alkaloid-based chemical defences in two different species of neotropical anurans are equally effective against the same arthropod predators. Journal of Tropical Ecology 32: 165-169.
49. Hovey, K.J.**, Viloria, M.O., and Saporito R.A. (2016) Oophaga pumilio (Strawberry Poison Frog). Predator-Prey Interactions. Herpetological Review 47(1): 113-114.
50. Jeckel, A.M., Saporito, R.A., and Grant, T. (2015) Variation in poison frog chemical defenses: Age explains richness, size explains quantity, sex explains nothing. Frontiers in Zoology 12: 27.
51. Saporito, R.A., Norton, R.A., Garraffo, H.M., and Spande, T.F. (2015) Taxonomic distribution of defensive alkaloids in Nearctic oribatid mites (Acari, Oribatida). Experimental and Applied Acarology 67: 317-333.
52. Andriamaharavo, N.R., Garraffo, H.M., Spande, T.F., Giddings, L., Vieites, D.R., Vences, M., and Saporito, R.A. (2015) Individual and geographic variation of skin alkaloids in three swamp-forest species of Madagascan poison frogs (Mantella). Journal of Chemical Ecology 41: 837-847.
53. Portik, D.M., Scheinberg, L.A., Blackburn, D.C., and Saporito, R.A. (2015) Lack of defensive alkaloids in the integumentary of four brilliantly colored African reed frog species (Hyperoliidae: Hyperolius). Herpetological Conservation and Biology 10: 833-838.
54. Jeckel, A.M.^, Grant, T., and Saporito, R.A. (2015) Sequestered and synthesized chemical defenses in the poison frog Melanophryniscus moreirae. Journal of Chemical Ecology 45: 505-512.
55. Saporito, R.A., Jones, A.W., and Snow, A. (2015) Pseustes poecilonotus (Bird-eating Snake). Predation by Herpetotheres cachinnans (Laughing Falcon). Herpetological Review 46(1): 106-107.
56. Mina, A.E.*, Ponti, A.K.**, Woodcraft, N.L.*, Johnson, E.E., and Saporito R.A. (2015) Variation in alkaloid-based microbial defenses of the dendrobatid poison frog Oophaga pumilio. Chemoecology 25: 169-178.
57. Paluh, D.J.*, Kenison, E.K., and Saporito, R.A. (2015) Frog or fruit? The importance of color and shape to bird predators in clay model experiments. Copeia 103: 58-63.
58. Stynoski, J.L.^, Torres-Mendoza, Y.*, Sasa-Marin, M., and Saporito, R.A. (2014) Evidence of maternal provisioning of alkaloid-based chemical defenses in the strawberry poison frog Oophaga pumilio. Ecology 95(3): 587-593.
59. Stuckert, A.M.^, Saporito, R.A., Venegas, P.J., and Summers, K. (2014) Alkaloid defenses of co-mimics in a putative Mullerian mimetic radiation. BMC Evolutionary Biology 14: 76-83.
60. Paluh, D.J.*, Hantak, M.M.**, and Saporito, R.A. (2014) A test of aposematism in the dendrobatid poison frog Oophaga pumilio: The importance of movement in clay model experiments. Journal of Herpetology 48: 249-254.
61. Hantak, M.M.**, Grant, T., Reinsch, S., McGinnity, D., Loring, M., Toyooka, N., and Saporito, R.A. (2013) Dietary alkaloid sequestration in a poison frog: An experimental test of alkaloid uptake in Melanophryniscus stelzneri (Bufonidae). Journal of Chemical Ecology 39(1): 1400-1406.
62. Wang, X., Li, J., Saporito, R.A., and Toyooka, N. (2013) Enantiodivergent synthesis of the quinolizidine poison frog alkaloid 195C. Tetrahedron 69: 10311-10315.
63. Alvarado, J.B., Alvarez, A., and Saporito, R.A. (2013) Oophaga pumilio (Strawberry Poison Frog). Predation by Baryphthengus martii (Rufous Motmot). Herpetological Review 44(2): 298.
64. Okaki, T., Fujimura, R., Sekiguchi, M., Zhou, D., Sugimoto, K., Minato, D., Matsuya, Y., Kato, A., Adachi, I., Tezuka, Y., Saporito, R.A., and Toyooka, N. (2013) Stereoselective total synthesis of (-)-Batzellasides A, B, and C. European Journal of Organic Chemistry 14: 2841-2848.
65. Hegna, R.H., Saporito, R.A., Donnelly, M.A. (2013) Not all colors are equal: Predation and color polytypism in the aposematic poison frog Oophaga pumilio. Evolutionary Ecology 27(5): 831-845.
66. Wang, X., Urata, N., Tezuka, Y., Wada, T., Sasaoka, T., Sakai, H., Saporito, R.A., and Toyooka, N. (2012) Synthesis and biological activities of the 3,5-disubstituted indolizidine poison frog alkaloid 239Q and its congeners. European Journal of Organic Chemistry 36: 7082-7092.
67. Saporito, R.A., Donnelly, M.A., Spande, T.F., and Garraffo, H.M. (2012) A review of chemical ecology in poison frogs. Chemoecology 22: 159-168.
68. Grant, T., Colombo, P., Verrastro. L., and Saporito, R.A. (2012) The occurence of defensive alkaloids in non-integumentary tissue of the Brazilian red-belly toad Melanophryniscus simplex (Bufonidae). Chemoecology 22: 169-178.
69. Savitzky, A.H., Hutchinson, D.A., Saporito, R.A., Burghardt, G.M., Lillywhite, H.B., and Meinwald, J. (2012) Sequestered defensive toxins in tetrapod vertebrates: Principles, patterns, and prospects for future studies. Chemoecology 22: 141-158.
70. Savitzky, A.H. and Saporito, R.A. (2012) Sequestration of defensive toxins by tetrapod vertebrates: Contributions in memory of John W. Daly. Chemoecology 22: 139-140.
71. Hegna, R.H., Saporito, R.A., and Donnelly, M.A. (2011) Contrasting colors of an aposematic poison frog do not affect predation. Annales Zoologici Fennici 48: 29-38.
72. Saporito, R.A., Norton, R.A., Andriamaharavo, N.R., Garraffo, H.M., and Spande, T.F. (2011) Alkaloids in the mite Scheloribates laevigatus: Further alkaloids common to oribatid mites and poison frogs. Journal of Chemical Ecology 37(2): 213-218.
73. Saporito, R.A., Isola, M., Maccachero, V.C., Condon, K., Donnelly, M.A. (2010) Ontogenetic scaling of poison glands in a dendrobatid frog. Journal of Zoology 282(2010): 238-245.
74. Andriamaharavo, N.R., Garraffo, H.M., Saporito, R.A., Daly, J.W., Razafindrakoto, C.R., Andriantsiferana, M. and Spande, T.F. (2010) Roughing it: A mantellid poison frog shows greater alkaloid diversity in some disturbed habitats. Journal of Natural Products 73(3): 322-330.
75. Saporito, R.A., Donnelly, M.A., Madden, A.A., Garraffo, H.M., and Spande, T.F. (2010) Sex-related differences in alkaloid defenses of the dendrobatid frog Oophaga pumilio from Cayo Nancy, Bocas del Toro, Panama. Journal of Natural Products 73(3): 317-321.
76. Daly, J.W., Ware, N., Saporito, R.A., Spande, H.M., and Garraffo, H.M. (2009) N-Methyldecahydroquinolines: An unexpected class of alkaloids from Amazonian poison frogs (Dendrobatidae). Journal of Natural Products 72(6): 1110-1114.
77. Saporito, R.A., Spande, T.F., Garraffo, H.M., and Donnelly, M.A. (2009) Arthropod alkaloids in poison frogs: A review of the 'dietary hypothesis'. Heterocycles 79(1): 277-297.
78. Daly, J.W., Garraffo, H.M., Spande, T.F., Giddings, L.A., Saporito, R.A., Vieites, D.R., and Vences, M. (2008) Geographic variation of skin alkaloids among individuals of three species of Madagascan poison frogs (Mantella). Journal of Chemical Ecology 34(2): 252-279.
79. Saporito, R.A., Zuercher, R., Roberts, M., Gerrow, K.G. and Donnelly, M.A. (2007) Experimental evidence for aposematism in the poison frog Oophaga pumilio. Copeia 4: 1006-1011.
80. Saporito, R.A. (2007) Gymnopis multiplicata (Purple Caecilian). Predation by Micrurus mipartitus (Many-banded Coral Snake). Predator prey interactions. Herpetological Review 38(2): 199.
81. Saporito, R.A., Donnelly, M.A., Jain, P., Garraffo, H.M., Spande, T.F., and Daly, J.W. (2007) Spatial and temporal patterns of alkaloid variation in the poison frog Oophaga pumilio in Costa Rica and Panama over 30 years. Toxicon 50(6): 757-778.
82. Saporito, R.A., Donnelly, M.A., Norton, R., Garraffo, H.M., Spande, T.F., and Daly, J.W. (2007) Oribatid mites as a major dietary source for alkaloids in poison frogs. Proceedings of the National Academy of Sciences 104(21): 8885-8890. Erratum - Table 1, correction - PNAS, 105(45): 17586.
83. Saporito, R.A., Donnelly, M.A., Garraffo, H.M., Spande, T.F. and Daly, J.W. (2006) Geographic and seasonal variation in alkaloid-based chemical defenses of Dendrobates pumilio from Bocas del Toro, Panama. Journal of Chemical Ecology 32(4): 795-814.
84. Saporito, R.A., Garraffo, H.M., Donnelly, M.A., Edwards, A.L., Longino, J. T., and Daly, J.W. (2004) Formicine ants: An arthropod source for the pumiliotoxin alkaloids of dendrobatid frogs. Proceedings of the National Academy of Sciences 101(21): 8045-8050.
85. Saporito, R.A., Donnelly, M.A., Hoffman, R.L., Garraffo, H.M., and Daly, J.W. (2003) A siphonotid millipede (Rhinotus) as the source for the spiropyrrolizidine oximes of dendrobatid frogs. Journal of Chemical Ecology 9(12):2781-2786.
* Indicates John Carroll undergraduate student.
** Indicates John Carroll graduate student.
^ Indicates visiting undergraduate or graduate student to my lab at John Carroll.