FISHERY BULLETIN: VOL. 86, NO. 3 



occurs between ages 1.5 and 2.5 years, but in the 

 major spawning population centers, over 95% of the 

 fish are <2 years (Uchiyama and Sampaga^). This 

 lack of older specimens and presence of fish in poor 

 physiological condition has led to suggestions that 

 this species is semelparous, with death after a single 

 spawning (Humphreys and Tagami 1986; Hum- 

 phreys et al. in press). The long interval between 

 spawning and recruitment for this species suggests 

 that oceanographic conditions in the North Pacific 

 regulate its distribution (Boehlert 1986). 



Published records of the pelagic distribution of 

 P. wheeleri are too few and varied to understand its 

 biogeography. In different years, specimens have 

 been caught in the Gulf of Alaska, near the Aleu- 

 tian Islands, and off the coasts of Japan, Oregon, 

 California, and British Columbia. In this paper, we 

 document the pelagic and benthic occurrences from 



'Uchiyama, J. H., and J. Sampaga. In review. Age and growth 

 of the pelagic armorhead, Pseudopentaceros wheeleri, at Hancock 

 Seamounts. Southwest Fisheries Center Honolulu Laboratory, 

 National Marine Fisheries Service, NOAA, 2570 Dole Street, 

 Honolulu, HI 96822-2396. 



both published and unpublished accounts, consider 

 this distributional pattern in light of general ocean- 

 ographic conditions in the North Pacific, propose 

 hypotheses about the migration and recruitment of 

 armorhead to the seamounts of the central North 

 Pacific, and assess interannual variation in abun- 

 dance and how it may relate to oceanographic 

 variability. 



MATERIALS 



The data sources used include published and un- 

 published collection records from throughout the 

 North Pacific Ocean. Published records on occur- 

 rences in Japan (Abe 1957, 1969; Zama et al. 1977; 

 Okamura et al. 1982), the eastern North Pacific 

 (Welander et al. 1957; Larkins 1964; Honma and 

 Mizusawa 1969; Chikuni 1970; Ignell et al. 1986), 

 and the west coast of North America (Wagner and 

 Bond 1961; Follett and Dempster 1963; Smith 1965) 

 were typically of single or a few specimens. Larger 

 numbers of unpublished collection records were in 

 data from large-scale surveys (Table 1). These data 



Table 1 .—Data bases searched for pelagic armorhead, Pseudopentaceros wheeleri, captures excluding single 

 collections and literature reports. Areas and seasons are averages over the years covered. 



'Salmon research data file. North Pacific Ocean, 1972-86. Salmon Division, Far Seas Fisheries Research Latxjratory, Shimizu, 

 Japan. 



2t^acy et al 1978 



sLarklns 1964. 



♦Data record of oceanographic observations and exploratory fishing. No. 1 (1957)-No. 28 (1985) Faculty of Fisheries, Hokkaido 

 University. 



sjapan Marine Fishery Resourse Research Center 1980, 1983a, 1983b, 1985 



^Biological data file of whales In the North Pacific Ocean, 1952-79. Whale Section, Far Seas Fisheries Research Laboratory, 

 Shimizu. Japan. See also ChikunI (1970). 



'Sloan 1983; Robinson and Jamieson 1984. 



'Z. Shyu, Taiwan Fisheries Research Institute, Keelung 20220, Taiwan, pers. commun. May 1987. 



^Ignell et al. 1986. 



454 



