KNIGHT; LARVAL DEVELOPMENT OF EUPHAUSIA EXIMIA 



0.1 mm 



Figure 5. — Euphausia eximia, northern form. Maxilliped, posterior view: a-b, 

 calyptopis I and III; c-d, furcilia IV-V, setules omitted on a, c, d. 



Antenna (Figure 10a) modified from natatory to 

 juvenile form, scale (exopod) with 11-13 (12) setae, 

 flagellum (endopod) with 4-6 (4) segments, 2 or 3 

 (2) peduncular and 2-4 (2) flagellar. 



Mandible (Figure 4c) modified with fewer, 

 somewhat broader incisor teeth and lacinia 

 mobilis missing or very much reduced; anterolat- 

 eral process very small. 



Maxilliped (Figure 5c) with 5 or 6 (6) setae on 

 distal segments of lengthening endopod; basis and 

 coxa with 6-8 (6-7) setae. 



Leg 2 exopod with 5 or 6 (5) setae, gill with three 

 lobes. 



Leg 3 endopod with >2 terminal setae, exopod 

 with 4-6 (5) setae; gill with three lobes, rarely with 

 bud of fourth lobe. 



Leg 4 endopod 5-segmented with 2-5 (2) termi- 



nal setae, exopod with 0-4 (0-2) setae; gill with 

 small third lobe. 



Leg 5 endopod usually unsegmented (ca. 3 seg- 

 ments occasionally seen) with 0-2 (0-1) terminal 

 setae; exopod nonsetose; gill sometimes with bud 

 of third lobe. 



Leg 6 rudimentary with exopod bud and 2 or 3 

 gill buds. 



Leg 7 with lightly pigmented photophore and 

 three-lobed gill; leg 8 with three gill lobes. 



Abdomen with photophores pigmented on seg- 

 ments 1,2, and 4, and sometimes forming on seg- 

 ment 3. 



Telson (Figure 6g) with 6-1 terminal spines and 

 3 pairs posterolateral spines (Table 1), 45% of 431 

 furcilia IV with 1 and 30% with 3 terminal spines 

 (frequencies similar to those observed on develop- 



321 



