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Research
General Interests I am a comparative animal physiologist. I investigate the respiratory, acid-base, and ionoregulatory physiology of aquatic animals, particularly those inhabiting waters with harsh water chemistry. I study mainly fish, but also have worked on crustaceans, insects, and amphibians.
Main Focus My main area of focus is the ionoregulatory physiology of fish that inhabit the ion-poor, acidic waters of the Rio Negro, a major tributary of the Amazon River. The waters of the Rio Negro drain nutrient-poor, jungle soils in northwest Brasil and are extremely dilute and acidic. So dilute and acidic, in fact, that a typical North American fish put in this river could die within a few hours. The problem for fish is that in very dilute and acid waters they have difficulty maintaining ion balance. These waters both stimulate diffusive ion loss and inhibit active transport across the gills. The end result is a net loss of salts that can be fatal. Despite these apparent challenges there are 1000+ species of fish inhabiting the Rio Negro. That's more species than in all the freshwaters of North America. The question is, how are they able to regulate ions under these condition? To try and answer that question, I study a variety of species of fish from the Rio Negro here in my lab in San Diego, in the laboratory of Dr. Adalberto Luis Val at INPA in Manaus, Brasil.
Other Interests My other interests include examining the physiological mechanisms that allow certain fish species to survive in hyper-saline waters as well as describing the physiological consequences of the transition to air-breathing in fish.
Some Recent Publications
Richards, J.G., Y.S. Wang, C.J. Brauner, R.J. Gonzalez, M.L. Patrick, P.M. Schulte, A.R. Choppari-Gomes, V.M. Almeida-Val, & A.L. Val. 2007. Metabolic and ionoregulatory responses of the Amazonian cichlid, Astronatus ocellatus, to severe hypoxia. Journal of Comparative Physiology B 177: 361 – 374. Gonzalez, R.J., R.W. Wilson & C.M. Wood. 2005. Ionoregulation in tropical fish from ion-poor, acidic blackwaters. In: The Physiology of Tropical Fishes (Val, A.L., Val, V.M.F.A. & Randall, D.J., eds), Fish Physiology Series, Vol. 21, pp. 397 – 442. San Diego: Academic Press. Gonzalez, R.J., J. Cooper* & D. Head. 2005. Physiological basis for tolerance of hyper-saline waters in sailfin mollies (Poecilia latipinna). Comparative Biochemistry and Physiology, Part A 142: 397 – 403. Preest, M., R.J. Gonzalez & R.W. Wilson. 2005. A pharmacological examination of the Na+ and Cl- transport mechanisms in freshwater fish. Physiological and Biochemical Zoology 78: 259 - 272. Brauner, C., T. Wang, Y. Wang, J.G. Richards, R.J. Gonzalez, N.J. Bernier, W. Xi, M. Patrick & A.L. Val. 2004. Limited extracellular but complete intracellular acid-base regulation during short-term environmental hypercapnia in the armored catfish, Liposarcus pardalis. Journal of Experimental Biology 207: 3381 – 3390. Sardella, B., J. Cooper, R. Gonzalez & C.J. Brauner. 2004. The effect of temperature on juvenile Mozambique tilapia hybrids (Oreochromis mossambicus x O. urolepis hornorum) exposed to full-strength and hypersaline seawater. Comparative Biochemistry and Physiology Part A, 137: 621 – 629. Sardella, B., V. Matey, J. Cooper, R. Gonzalez & C.J. Brauner. 2004. Physiological, biochemical, and morphological indicators of osmoregulatory stress in ‘California’ Mozambique tilapia (Oreochromis mossambicus x O. urolepis hornorum) exposed to hypersaline water. Journal of Experimental Biology 207: 1399 - 1413. Wood, C.M., A.Y.O. Matsuo, R.W. Wilson, R.J. Gonzalez, M.L. Patrick, R.C. Playle & A.L. Val. 2003. Protection by natural blackwater against disturbances in ion fluxes caused by low pH exposure in freshwater stingrays endemic to the Rio Negro. Physiological and Biochemical Zoology 76: 12 – 27. Wang, Y., R.J. Gonzalez, M.L. Patrick, M. Grosell, C.G. Zhang, Q. Feng, J.Z. Du, C.M. Wood, & P.J. Walsh. 2003. Unusual physiology of scaleless carp, Gymnocypris przewalskii, in Lake Qinghai: A high altitude alkaline saline lake. Comparative Biochemistry and Physiology Part A 134: 409 – 421.
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Dr. Richard J. Gonzalez, Ph.D |
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Department of Biology |
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Professor & Chair |
