Gnath ophausia — P EQU egn AT 
415 
Fig. 10. Geographical Distribution of Gnathophausia gracilis. Solid circle, captures of the Dana Expe- 
dition; plus sign, other previous captures; solid triangle, captures from the 1950-53 Scripps collections. 
TABLE 5 
Distribution of Gnathophausia gracilis According 
to Size in Atlantic and Pacific Oceans 
(from Fage, 1941) 
NUMBER 
OF INDI- 
LENGTH 
ATLANTIC 
PACIFIC 
VIDUALS 
(mm) 
East 
West 
East 
West 
79 
50-70 
5.0% 
2.5% 
58.2% 
34.2% 
14 
71-100 
7.1% 
57.1% 
0 
35.7% 
he found all the adults to be of relatively small 
size, as shown in Table 5. 
Table 6 similarly illustrates the numbers and 
percentages of the various sized individuals in 
the Scripps collections taken from two portions 
of the eastern Pacific: (1) north of 23°N (where 
Fage lists no captures from the Dana), and 
(2) south of 23°N. Thus it can be seen that 
of the specimens coming from south of the 
Tropic of Cancer, the majority (75.9%) are 
less than 80 mm in length (without the ros- 
trum). This percentage actually refers to speci- 
mens under 60 mm in length, since no speci- 
mens between 6l and 80 mm were found in 
samples from this southern region in the 
Scripps collections. From the area north of the 
Tropic of Cancer the majority of the speci- 
mens taken (59.6%) were of the larger size, 
i.e., greater than 80 mm. Apparently the size 
difference noted by Fage would not apply m 
the entire eastern Pacific, but only to that por- 
tion within the tropical zone, and particularly 
in the area of the Gulf of Panama where, in- 
deed, a dwarf form does seem to exist, which 
reaches sexual maturity at half the size of the 
normal adult G. gracilis. 
