equally represented — 160 females and 169 

 males. Sizes ranged from 63 mm. to 193 ram. 

 in carapace length. All types of presently 

 recognized shell conditions were also re- 

 presented, as the Scimples varied from newly 

 molted, soft-shelled crabs to those having 

 bcirnacle-encrusted very old shells. The 

 majority of the crabs, however, possessed 

 hard new shells indicating a molt within 

 the season. 



Anatomically, the stomach of the king 

 crab is divided into two sections, referred 

 to as the cardiac and pyloric sections. 

 (Marukawa 1933). This conventional nomen- 

 clature will be used in this report. How- 

 ever, as pointed out by Pearson (1908), 

 these terms may technically be misnomers 

 when applied to the Malacostraca since the 

 cardiac section of the stomach is farthest 

 from the heart, and lies under the region 

 of the carapace defined as the gastric re- 

 gion (fig. 2) by Marukawa. Figure 3 shows 

 the position of the stomach, with relation 

 to the carapace and the rest of the body. 



in 4 percent formalin in an individual 

 cloth bag. The pyloric section and the 

 intestine were not used in this study. 

 Anatomically the cardiac section of the 

 stomach is divided into two parts. The 

 anterior part, which comprises the largest 

 area of the entire stomach, is guarded at 

 its entrance by a hairy filter and at its 

 exit by the teeth of the gastric mill. 

 The smaller part of the cardiac stomach 

 lies between the teeth of the gastric mill 

 and the pyloric valve which is the entrance 

 to the pyloric section of the stomach. 

 When the stomach is filled to maximum capa- 

 city in both sections, the ratio of the 

 amount of food in each of the three parts 

 is 6:2:1 respectively (Feniuk 1945). Each 

 percentage of fullness was assigned a coded 

 index (table 1). Each part was considered 

 individually and the fullness estimated 

 visually: 



Table 1. — Code for relative fullness 

 of stomachs. 



The cardiac section of the stomach 

 was dissected out of each crab and preserved 



Percentage of 

 fullness 



Index (k„) 



Figure 2. — Carapace of king crab (after 

 Marukawa) G.R. , Gastric region; C.R. , 

 Cardiac region; B.R., Bramchail region. 



Empty 

 Trace of food 



1-20 

 21 - 40 

 41 - 60 

 61 - 80 

 81 -100 





 1 

 2 

 3 

 4 

 5 

 6 



In order to eliminate variations due 

 to the different sizes of the parts of the 

 stomach, a common index of K^. was obtained 

 for each part by multiplying its index of 

 fullness (kx) by its factor taken from the 

 ratio of the parts to the whole. The total 

 K factor represents the sum of the Kx fac- 

 tors, i.e., K = 6kj^ + 2k2 (+ lk3 not used 

 in these samples). With the entire cardiac 

 stomach filled to maximum capacity, the 

 maximum K obtainable in our samples if 48 

 units. The percentcige of fullness of the 

 stomach, both parts considered, is thus 

 calculated from this K factor. The quan- 

 tity of food present in the stomachs varied 

 considerably; however, only 7.6 percent of 

 the stomachs were found to be completely 

 empty. Table 2 shows the distribution of 

 stomach fullness. 



