SVERDRUP ET Al. : "E. W. SCRIPPS" CRUISES, 1938 



29 



Euchirella^ 



curt i Cauda 



galeata 



messinensis 



propria * 



pulchra 



^ rostrata 



Euterpina acutifrons 



„ , ( secundus 



Gaetanus 



unicornis 

 Gaidius pungens 



f- acutifrons * 

 longicornis * 

 ornatus * 



Haloptilus 



^ sp iniceps " 

 [ clausi 

 Heterorhabdus i longicornis 

 [ papilliger 



Labidocera i i — ■. 



L tnspinosa 



Lophothrix frontalis 



Lubbockia ( aculeata? )* 



Lucicutia flavicornis 



Macrosetella sp.* 



atra 



Metridia ' boecki 



. lucens 



Microsetella rosea 



V • n / minor * 



hormonilla i — r ^^ 



L pnasma* 



Oithona plumifera 



Oithonina nana 



Oncea conifera 



Oncea spp. 



f abdominalis ■ 

 PleuromaTTTTia j gracilis 



[ ziphias 

 Pontellopsis occidentalis 



Scolecithricella subdentata 

 Scolecithrix danae 

 Scottocalanus persecans 

 Tortanus discaudatus* 



Undeuchaeta 



bispinosa 



major 



minor 



Vettoria granulosa* 



Most of the species were represented at all 

 stations on one or more cruises. A few were al- 

 ways widely distributed and were rarely absent 

 from any station, though varying in numbers. 

 Among these may be mentioned Eucalanus bungii 

 californicus and Calanus finmarchicus and some 

 unidentified microcalanids. Of the species most 

 closely bound to the immediate coast may be men- 

 tioned Tortanus discaudatus , Oithonina nana , 

 Acartia clausi , and A. tonsa . The more typi- 

 cally oceanic forms are Corissa parva , Acartia 

 danae , Copilia mirabilis and Eucalanus elongatus . 

 A few normally deep-water species came within 

 reach of the net, for example, Aegisthus mucrona- 

 tus. At no time was there evidence of any one 

 species dominating markedly in numbers over all 

 others, as is so characteristic at times in bore- 

 al waters. Calanus finmarchicus , the most im- 

 portant of the boreal Atlantic species, was only 

 moderately numerous, competing with Eucalanus 

 bungii californicus for first place numerically 

 among the larger copepods. This was perhaps to 

 be expected, since it appears that in the open 

 waters of the Northwest Pacific from the Bering 

 Sea southward, C. finmarchicus has also for the 

 most part relinquished its place to other members 

 of the same genus, namely, C. tonsa and C. cris- 

 tatus, and to the two varieties of Eucalanus 

 bungii. A heterogeneous group of small copepods 

 lumped as "microcalanids" and Oithona spp. were 

 numerically most abundant of all the copepods. 

 Unidentifiable immature calanoids were also very 

 abundant . 



In general, the stations situated about mid- 

 way between the outer and inner ends of the sec- 

 tions, that is, the stations falling within the 

 zone generally characterized by mixed water, show 

 the greatest numbers of individuals of the nu- 

 merically important species such as 0. finmarchi- 

 cus , E. bungii californicus , and the "microcala- 

 nids." 



There is marked evidence of copepod reproduc- 

 tion throughout the period investigated (April to 

 December) , but the greatest number of nauplius 

 larvae were taken in April and June at stations 

 along the southern sections. In August the great- 

 est numbers occurred along the northern sections. 

 In October the numbers had fallen off but some 

 increase was again indicated for December at some 

 stations. 



