Calanoid Copepods from Midwater Trawl Collections 
Made in the Southeastern Pacific Ocean 1 
George D. Grice and Kuni Hulsemann 2 
In addition to the fishes and faster swimming 
invertebrates (euphausiids, squids) usually ob- 
tained in midwater trawl collections, relatively 
large species of copepods are also frequently 
captured. Aside from Sewell’s (1929) report 
of copepods found in six midwater collections 
made in the Indian Ocean, it has only been in 
recent years that midwater trawl samples have 
been more or less systematically analyzed for 
copepods. From the Florida Current, off Miami, 
an area in which the copepods have been studied 
fairly extensively, Owre and Foyo (1964) re- 
ported that 21 calanoid species were found only 
in collections made by the Isaacs-Kidd midwater 
trawl (Isaacs and Kidd, 1953). Of these, 11 
represented new records for the area. In the 
southwestern Indian Ocean, De Decker and 
Mombeck (1965) using both vertical plankton 
net and midwater fish trawl found 274 species 
of copepods. Of these the fish trawl accounted 
for 115 species including 43 which were not 
found in the plankton net collections. In the 
western Indian Ocean Grice and Hulsemann 
(1967) studied a series of 30 plankton net and 
21 midwater trawl collections obtained between 
18°N and 40°S. In the midwater trawl col- 
lections were found 64 species not present in the 
plankton net collections, including representa- 
tives of all eight species of the family Mega- 
calanidae. It thus appears that midwater nets 
constitute a valuable additional means of sam- 
pling the calanoid copepod fauna in an open 
ocean area, and it is hoped that those interested 
in copepods will examine any available mid- 
water trawl samples. 
The samples examined in this study were 
1 Contribution No. 1934 from the Woods Hole 
Oceanographic Institution. This study was supported 
by National Science Foundation Grants GB3479 and 
GB6052 and by the Southeastern Pacific Biological 
Oceanographic Program. Manuscript received April 
26, 1967. 
2 Woods Hole Oceanographic Institution, Woods 
Hole, Massachusetts 02543. 
obtained in the southeastern Pacific Ocean dur- 
ing Cruise 13 of R/V "Anton Bruun” by 
means of a 10-ft Isaacs-Kidd midwater trawl. 3 
They were collected at intervals along a tran- 
sect of stations extending seaward from Val- 
paraiso, Chile, for a distance of approximately 
1,000 nautical miles between 33° and 34°S 
(Table 1). Of the 29 trawl collections examined, 
18 sampled within the upper 1000 m and the 
remaining 11 sampled greater depths. A total of 
904 calanoid copepods were removed from the 
samples aboard ship and subsequently identified 
in our laboratory. 
In all, 78 species of calanoid copepods be- 
longing to 11 families (Table 2) were identi- 
fied. In general, these are widely distributed 
species and most of them occur also in the 
deeper waters of the Atlantic and Indian 
oceans. Comparing these observations, for ex- 
ample, with a series of midwater trawl samples 
collected in the Indian Ocean (Grice and 
Hulsemann, 1967) we find that 68% (53 
species) of the species from the southeastern 
Pacific are also present in the Indian Ocean. 
Furthermore, 81% of the species occur also in 
the Atlantic. Of the 78 species we found, 13 
have previously been reported from the waters 
adjacent to the coast of Chile (Fagetti, 1962); 
7 have not previously been reported from the 
Pacific Ocean (these are marked with an 
asterisk in Table 2); and 6 other species, 
Bradycalanus typicus A. Scott, Euchaeta gracili- 
cauda (A. Scott), Euchaeta weberi (A. Scott), 
Euchirella formosa Vervoort, Euchirella indica 
Vervoort, Lophothrix gigas (A. Scott), have 
been reported only from the Malay Archipelago. 
Also found in the collections were 6 new 
species and the hitherto undescribed adult fe- 
male and undescribed male of 2 other species. 
Descriptions of these 8 species are given below 
3 The help of Dr. Giles Mead and his scientific 
party who secured the samples is gratefully acknowl- 
edged. 
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