ARMETTA and STEVENS: BIOLOGY OF THE HAIR CRAB 



600 -n 



All Males, 1979-1984 



500- 



to 



0) 

 J2 



400- 



300- 



200 — 



100 — 



20 40 60 80 100 120 140 160 



40 — 



20- 



— 



All Females, 1979-1984 



^ 



20 40 60 80 100 120 140 160 



Carapace length (mm) 



P'lGURE 9. — Carapace length frequencies of Enmacrus isenheckii collected during NMFS 

 summer surveys in the eastern Bering Sea, 1979-84. Data for all 6 years were combined. 

 Note scarcity of specimens below about 45 mm CL. 



(range 17-145 mm); females averaged 65.5 mm 

 CL (range 14-111 mm). Median values were 98 

 mm CL for males and 63 mm CL for females. The 

 combined length-frequency distributions of male 

 and female hair crab, 1979-84, are shown in Fig- 

 ure 9. In order to facilitate conversion between 

 different methods of measurement, we calculated 

 regression relationships between length, width, 

 and weight (Table 6). 



DISCUSSION 



Distribution and Abundance 



The decline of the EBS hair crab population 

 occurred during the same time period (1980-84) in 

 which substantial declines of red and blue king 

 crabs (Paralithodes camtschatica and P . platypus , 

 respectively), as well as two species of snow (Tan- 



Table 6. — Regression relationships for length, weight, and width of Erimacrus 

 isenbeckii. from the eastern Bering Sea. Length Is carapace length from orbit. 



539 



