PELAGIC AMPHIPOD — BOWMAN AND McCAIN 



Neritic distribution. — As shown in figure 2, C. challengeri is 

 widespread in the Puget Sound region. To the north it also occurs 

 in Hecate Strait and in at least some of the straits between the 

 islands of the Alexander Archipelago. Details of its vertical dis- 

 tribution are poorly known, but large numbers were taken with 

 Isaacs-Kidd trawls in the upper 100 m in Lynn Canal, Alexander 

 Archipelago. 



Global Distribution 



The world-wide distributional pattern of C. challengeri outside of 

 the North Pacific, shown in figure 3, is puzzling. Many zooplankton 

 species inhabiting Subarctic Water do not occur elsewhere, for ex- 

 ample: the polychaete worm Tomopteris jmcijicus (Tebble, 1962); the 



Figure 3. — World distribution records of Cyphocaris challengeri outside of the North Pacific. 



copepods Calanus cristatus, C. idumchrus, Eucalanus bungii bungii, 

 Candacia columbiae, and others (Brodsky, 1957; Johnson, 1941; 

 Omari, 1965); the eu-phsbusiids Eujjhausia pacifica, Tessarabrachion 

 oculatus, and Thysanoessa longijyes (Brinton, 1962); and the hyperiid 

 amplipod Pamthemisto jMcifica (Bowman, 1960). As far as we know, 

 none of the subarctic epipelagic plankters has a global distribution 

 comparable to that of C. challengeri. It is perhaps significant that 

 almost all the collections outside of the North Pacific were made 

 with nets that had been lowered to considerable depths, mainly 

 1000-3000 m. Altho these were not closing nets and the depth of 

 capture is uncertain, it is possible that C. challengeri undergoes a 

 submergence at lower latitudes. An alternative possibility, that 

 more than one species is involved, cannot be properly evaluated 

 until abundant material from all parts of the geographic range 

 becomes available. 



