fied as A. stomias, and 81 as A. evermanni. Gill 

 rakers decreased in number from the first to the 

 third gill arches in both species. Neither species had 

 gill rakers on the fourth gill arch (though they did 

 have rudiments). 



First Gill Arch 



In general, A. stomias had more gill rakers (on 

 both the upper and lower limbs) on the first gill arch 

 than did A. evermanni; however, the counts did 

 overlap both in arrangement of gill rakers and total 

 numbers (Table 1). Of the A. stomias examined, 

 75.2% had 4 or more rakers on the upper limb and 

 none had fewer than 3. On the other hand, no A. 

 evermanni had 4 or more gill rakers, and 49.4% had 

 2 rakers on the upper limb on the first gill arch. 



Second Gill Arch 



As was the case of the first gill arch, A. stomias, 

 in general, had more gill rakers on the second gill 

 arch than did A. evermanni. There were minor over- 

 laps (1.8%) between these two species in the total 

 gill raker counts and in the distribution of the gill 

 rakers (Table 2). In addition to having different gill 

 raker counts and patterns, all of the A. everTnanni 

 examined had 1 gill raker on the upper limb of the 

 second gill arch, whereas 98.2% of the A. stomias 

 had 2 gill rakers on the upper limb of the second 

 gill arch (Table 2). 



Third Gill Arch 



In general, A. stomias had more gill rakers on the 

 third gill arch than did A. evermanni. The range of 

 total raker counts for A. stomias was 3 to 7, with 

 most (85.3%) having 4 or 5. Total raker counts for 

 A. evermanni ranged from 2 to 5, with 64.2% hav- 

 ing 3. The most frequent arrangements of gill rakers 

 on the third gill arch oiA. stomias were -t- 4 (43.5%) 

 and 0-1-5 (41.2%), and the most frequent arrange- 

 ment for A. evermanni was -t- 3 (64.2%). Only three 

 (1.8%) A. stomias had one gill raker on the upper 

 limb of the third gill arch. The rest (98.2% A. 

 stomias and all A. evermanni) had no gill rakers on 

 the upper limb of the third gill arch. 



Anomalous Specimens 



Three specimens had the upper eye interrupting 

 the profile of the head but had only 1 gill raker on 

 the upper limb of the second gill arch. These fish 

 were probably A. stomias with anomalous gill raker 



Table 1 .—Gill-raker arrangements and their per- 

 centages (%) of frequency of occurrence (FO) on 

 the first gill arches (eyed side) of Atheresthes 

 stomias and Atheresthes evermanni collected from 

 eastern Bering Sea. 



Table 2.— Gill-raker arrangements and their per- 

 centages (%) of frequency of occurrence (FO) on 

 the second gill arches (eyed side) of Atheresthes 

 stomias and Atheresthes evermanni collected from 

 the eastern Bering Sea. 



'All of these A. stomias have two gill rakers on the upper 

 limbs of the second gill arches of the blind side. Their pat- 

 terns are either 2+10 or 2 + 9. 



counts. One of the three had gill raker patterns of 

 4 + 11, 1 + 9, and + 4 on the first, second, and third 

 gill arches, respectively. The gill raker patterns on 

 the blind side of this specimen were 3-1-11 on the 

 first gill arch, 2 + 9 on the second, and + 4 on the 

 third. Thus, because this specimen had 4 gill rakers 

 on the upper limb of the first gill arch on the eye 



610 



