FISHERY BULLETIN: VOL. 74, NO. 4 



that I KMT data were included in three of the four 

 quarters, only the first quarter (January-March) 

 lacking IKMT data. Small shrimp were propor- 

 tionately most abundant during the third quarter 

 (July-September), and large shrimp were most 

 abundant during the first quarter, although lack of 

 IKMT data probably affected the shape of the first 

 quarter histogram. 



Diet (Table 5) 



Seven of the twelve shrimp from DSB III had 

 eaten calanoid cope pods, mostly Pleuromamma 

 spp. 



Sergia fulgens (Hansen 1919) 



Vertical Distribution (Figure 17) 



Because of the peculiar fluctuations in abun- 

 dance during the course of the sampling program, 

 the vertical distribution patterns of 5. fidgeits 

 derived from the data should be regarded strictly 

 as estimates. All the daytime captures lay between 

 550 and 625 m; there was no variation in depth 

 with increasing size. The open tows of the 

 December 1970 cruise took nine specimens 

 between 525 and 630 m. Most nighttime captures 

 lay between 75 and 125 m for immature shrimp 

 less than 8 mm CL, with some as shallow as 25-50 

 m. Nearly all the adults came from a single tow at 

 150-200 m; a few captures came as shallow as 75 m. 

 Almost all of the captures near full moon came 

 during the June 1973 cruise, which took immature 

 shrimp between 250 and 475 m; there were three 

 captures of adults between 150 and 325 m. The 

 peak in the upper 25 m is a sampling artifact. The 

 December 1970 cruise took nine adults in open 

 tows between 160 and 300 m and one adult at 400 

 m. There was no evidence of full moon non- 

 migration. 



Population Size, Growth, and 

 Reproduction (Figure 18) 



Sergia fulgens fluctuated drastically in abun- 

 dance during the sampling program. The first 13 

 cruises of the Teuthis series (Teuthis IV-XVII, 

 February 1971-August 1972) caught a total of 13 

 specimens. After the September 1972 cruise it 

 turned up in many tows, often in very large 

 numbers. Nearly all the specimens were immature 

 shrimp less than 10 mm CL. However, one hor- 



M 6 



10 12 14 16 



20 UO 



200 

 400 

 600 

 800 

 1000 

 1200 



200 

 400 

 600 

 800 



1000 

 1200 



200 

 400 

 600 

 800 

 1000 

 1200 



Figure 17. -Vertical distribution of Serbia fulgens 



SERGIA FULGENS 



cf 



JAN-UAR 



1 1 ^ 1 r 



3 0- 



[L 



^ ^ , 



iia 



.=^50- 



A 



-D£C 



 r"^n ■?=- 



CARAPACE LENGTH (mm) 



Figure 18.-Quarterly size-frequency distribution of Sergia 



fulgens. 



izontal night tow in May 1973 took 89 adults. In 

 addition, the December 1970 cruise caught a total 

 of 21 S. fulgens; 19 of these were adults. Combining 

 the very low numbers from the first 13 horizontal 

 series with the very high numbers from the last 3 

 horizontal series gives an average population 



816 



