(1970) at each latitude except lat. 3°30'S (four 

 tows). Towing speed was about 2 knots (ca. 1 m/s). 

 All tows were made at night; the trawl was at 

 depth for about 6 h each tow (2000-0200 h). Depths 

 of tows were estimated from amount of wire out, 

 wire angle, and depth determinations made on 

 later cruises with a time-depth recorder. Two 

 depth zones were sampled— 20-30 m and 50-75 m. 

 These will be referred to as "shallow" and "deep" 

 tows, respectively. Depth of tow was alternated 

 nightly except at the equator where all tows were 

 deep. Station numbers, exact positions, depths, 

 and dates are given in Table 1. 



Table 1. -Station numbers, positions, towing depths, and dates 

 of mid-water trawl collections taken May-June 1969 on cruise 43 

 of the RV Townsend Cromwell. 



Station 

 number 



Position 



Lat. 



Long. 



Depth 

 (m) 



Date 



8 

 10 

 12 

 14 

 16 

 22 

 24 

 26 

 28 

 30 

 36 

 38 

 40 

 42 

 44 

 46 

 48 

 50 

 52 

 54 

 55 

 57 

 59 

 61 



12°04' N 

 12^03' N 

 12°11' N 

 11°56' N 

 11°58' N 

 07=41' N 

 07°27' N 

 07=33' N 

 07=33' N 

 07=19' N 

 03=29' N 

 03=30' N 

 03=31' N 

 03=32' N 

 03=40' N 

 00=01' N 

 00=04' N 

 00=03' N 

 00=01' N 

 00=04' N 

 02=59' S 

 03=31' S 

 03=34' S 

 03=35' S 



144=54' W 

 144=55' W 

 145=11' W 

 144=54' W 

 144=57' W 

 145=01' W 

 145=05' W 

 144=50' W 

 144=48' W 

 145=09' W 

 145=03' W 

 145=06' W 

 145=00' W 

 144=59' W 

 144=54' W 

 144=50' W 

 145=07' W 

 145=05' W 

 145=03' W 

 144=59' W 

 144=53' W 

 145=11' W 

 145=00' W 

 145=11' W 



20-30 

 50-75 

 20-30 

 50-75 

 20-30 

 50-75 

 20-30 

 50-75 

 20-30 

 50-75 

 20-30 

 50-75 

 20-30 

 50-75 

 20-30 

 50-75 

 50-75 

 50-75 

 50-75 

 50-75 

 20-30 

 50-75 

 20-30 

 50-75 



7 May 



8 May 



9 May 



10 May 



11 May 



13 May 



14 May 



15 May 



16 May 



17 May 



19 May 



20 May 



21 May 



22 May 



23 May 



25 May 



26 May 



27 May 



28 May 



29 May 



30 May 



31 May 



1 June 



2 June 



Except for very large samples, the entire collec- 

 tion was preserved and counted. When total 

 volume of the sample exceeded ca. 4 gallons (ca. 15 

 liters), 1-gallon (ca. 4 liters) subsamples were 

 preserved, and counts were adjusted according to 

 the original total volume. Specimens were iden- 

 tified primarily from Nafpaktitis (1968), Nafpak- 

 titis and Nafpaktitis (1969), and an unpublished 

 manuscript kindly provided by R. L. Wisner.^ 



During cruise 43, bathythermograph casts to 300 

 m were made at approximately 50-km intervals 

 between lat. 14° and 3°N and at approximately 



16-km intervals between lat. 3°N and 3°S. 

 Salinity- temperature-depth casts to 500 m were 

 made every degree from lat. 14° to 3°N and every 

 32 km from lat. 3°N to 3°S. 



We have also counted the myctophids from 12 

 tows with a 10-foot (3 m) Isaacs- Kidd mid- water 

 trawl (IK) taken 5-11 February 1970 at lat. 3°30'N, 

 long. 145°W during cruise 47 of the Townsend 

 Cromwell. These tows were all taken at night. 

 Towing depths were 50-500 m; each tow spent 

 about 2 h at depth (Table 2). The data from these 

 tows along with data on vertical distribution of 

 myctophids near Hawaii, somewhat north and 

 west of the sampling area (Clarke 1973), allow us 

 to estimate whether the absence of certain species 

 from Cobb trawl tows in some zones was due to the 

 species' simply occurring deeper than the Cobb 

 trawl sampled. 



Table 2.-Station numbers, towing depths, and dates of mid- 

 water trawl collections taken near lat. 3°30'N, long. 145°W, 

 February 1970 on cruise 47 of the RV Townsend Cromwell. 



station Depth 



number (m) Date 



48 

 49 

 52 

 57 

 58 

 60 

 61 

 67 

 68 

 69 

 76 

 78 



50 

 50 

 450 

 200 

 100 

 500 

 300 

 300 

 100 

 200 

 450 

 500 



5 Feb. 



5 Feb. 



6 Feb. 



7 Feb. 

 7 Feb. 



7 Feb. 



8 Feb. 



9 Feb. 

 10 Feb. 

 10 Feb. 



10 Feb. 



11 Feb. 



'Wisner, R. L. Annotated and illustrated key to the identifica- 

 tion of fishes of the family Myctophidae of the eastern Pacific 

 Ocean, eastward of 160° West Longitude. Unpubl. manuscr., 

 Scripps Institution of Oceanography, La JoUa, CA 92037. 



RESULTS AND DISCUSSION 



The slope of the isotherms on the temperature 

 profile of the transect (Figure 1) indicate the loca- 

 tions of the major currents of the area. The North 

 Equatorial Current (NEC) extended to about lat. 

 9°N, the Equatorial Counter Current (ECC) from 

 about lat. 4° to 9°N, and the South Equatorial 

 Current (SEC) southward from about lat. 4°N. The 

 Cromwell Current or Equatorial Undercurrent 

 (EUC) was centered about on the equator. Thus 

 the lat. 12°N samples were taken within the NEC, 

 the lat. 7°30'N samples just south of the boundary 

 between the NEC and the ECC, and the other 

 samples in the SEC, the lat 0° samples actually 

 being in the upper layers of the EUC. 



A total of 32 species of myctophids were taken 

 by the CT collections. The catches per tow are 

 given in Table 3. Failure to catch a given species at 



634 



