Hoff: Biology and ecology of Gymnocanthus pisMgenn the eastern Bering Sea 



721 



1 

 0.9 

 0.8 



0.7 



o) 0.6 



o 



I 0.5 



o 0.4 



o 

 ol 



0.3 



0.1 



HFish 



 Shrimp 



H Unidentified 



@ Crustacean 



HMollusk 



EaWorm 



D Amphipod 



<100 



100-124 125-149 



Length groups (mm) 



150-201 



Figure 10 



Proportion of the total weight of all prey groups by the total-length groups ofGymnoconthus pifitilliger for 1997. (n=20. 

 29, 28, and 16 for each length group, respectively). 



mum depth, maximum age and size, and diet preferences 

 between western and eastern North Pacific populations. 

 The eastern Bering Sea and Kamchatka shelf habitats 

 have different currents, sahnities, sediment types, shelf 

 area, and temperatures (Pavlov and Pavlov, 1996) and 

 these different oceanographic features may be reflected in 

 the local adaptation patterns of G. pistilliger in this area. 

 Smith et. al ( 1997 ) reported on the biology of Gymnocan- 

 thus tricuspis, a congener of G. pistilliger, which is abun- 

 dant in the Chukchi Sea and Norton Sound, Alaska (Allen 

 and Smith, 1988). The two species oi Gymnocanthus are 

 very similar and probably occupy the same ecological niche 

 in different environments. Smith et. al ( 1997) reported sim- 

 ilar ages up to 9 years of age and similar densities and 

 interannual variations in populations of G. tiicuspis as 

 were found for G. pistilliger. The ecological importance of 

 Gyirmocanthus throughout its range is not well understood 

 but undoubtedly significant because of its high abundance 

 and role as prey and competitive predator 



Acknowledgments 



I would like to thank the crew and scientific parties of the 

 vessels Arcturus and Aldebaran for their efforts in collecting 



data and in collecting biological specimens. I would also like 

 to thank the reviewers Troy Buckley, Bill Gale, Doug Markle, 

 Dave Somerton, Gary Stauffer, and Gary Walters and the 

 unidentified journal reviewers. All gave many helpful sug- 

 gestions that improved the content of the manuscript. 



Literature cited 



Allen, M. J., and G. B. Smith. 



1988. Atlas and zoogeography of common fishes in the 

 Bering Sea and Northeast Pacific. U.S. Dep. Commer., 

 NOAA Tech. Report NMFS-66, 151 p. 

 Brodeur, R. D., and P. A. Livingston. 



1988. Food habits and diet overlap of various eastern Bering 

 Sea Fishes. U.S. Dep. Commer., NOAA Tech. Memo. 

 NMFS/NWC-127, 76 p. 

 Corcobado-Onate, F. 



1991. Food and daily ration of the rock sole Lepidopsetta 

 bilineata (Pleuronectidae) in the eastern Bering Sea. Mar. 

 Biol. 108:185-191. 

 Environmental Systems Research Institute. 



1996. Arcview GIS, ver. 3.0. Environmental Systems Re- 

 search Institute, Redlands, CA, 614 p. 

 Fadeev, N. S. 



1968. Comparative outline of the biology of flatfishes in the 

 southeastern part of the Bering Sea and condition of their 



