13. Cameron, J.N., and Wood, C.M.  (1978)  Renal function and acid-base regulation in two Amazonian Erythrinid fishes:  Hoplias malabaricus, a water-breather, and Hoplerythrinus unitaeniatus, a facultative air-breather.  Can. J. Zool. 56:  917-930.  (Alpha Helix Symposium Issue — Water-air Transition in Vertebrates of the Amazon.) (PDF)