350 EIGHTH PACIFIC SCIENCE CONGRESS 



though by no means verified, that most such fishes arrived in Hawaii 

 as planktonic larvae carried in by the ocean currents. Under such pos- 

 tulates the current systems should play a dominant role in the develop- 

 ment of the Hawaiian inshore fish fauna. 



However, there seems to be little correlation between the present 

 current systems of the Hawaiian region and the fish immigration routes. 

 Although the Hawaiian inshore fish fauna has come in from the south 

 and west, there are no known northeasterly-flowing currents reaching 

 the Hawaiian Islands (see Sverdrup, Johnson, and Fleming, 1942, Chart 

 VII). The North Equatorial Current, in which Hawaii lies, flows to- 

 ward the west, and the eastwardly flowing Equatorial Counter Current 

 does not pass within 800 miles of these islands. If the derivation of 

 the Hawaiian inshore fishes is to be tied in with present current sys- 

 tems there would seem to be only two possibilities, both in my opinion 

 rather remote. One is that the larval forms were carried to the east 

 of Hawaii in the Counter Current and then doubled back in a great 

 eddy of the North Equatorial Current that carried them over 800 miles 

 north. The other is that Hawaiian fishes were carried in to Kure and 

 Midway from the Bonins and Japan by a southern tongue of the Ku- 

 roshio Current (see Sverdrup, Johnson, and Fleming, 1942: 122). This 

 would involve transport in a slowly moving current across more than 

 2000 miles of deep water. 



There is of course the possibility that the current systems of the 

 Hawaiian area were different in the Pleistocene than they are today. 

 However, Arrhenius (1952) has shown that there was little or no dis- 

 placement of, at least, the Equatorial Counter Current during the Pleis- 

 tocene. 



If the immigration of Hawaiian fishes took place randomly, e.g., 

 via occasional eddies within the major current systems, then it would 

 seem logical that they came in from the nearest islands, namely, John- 

 ston and Wake. There is indeed considerable evidence in the Johnston 

 fish fauna that this island has formed something of a way point in both 

 the immigration and emigration of Hawaiian fishes. 



Nature of the Hawaiian Fish Fauna 

 Before treating the endemism among Hawaiian fishes it seems ad- 

 visable to divide these into several ecological categories. First, there 

 are a small number of Hawaiian fishes, mostly gobies, that have taken 

 up a primarily fresh-water existence in the streams of the high islands. 

 At the other end of the scale are the deep-water fishes, both bathy- 

 pelagic and bottom dwelling forms. Third, there is a group in which 

 the adults are pelagic, e.g., most sharks, the tunas, flying-fishes, and 



