KNIGHT: DEVELOPMENT OF EUPHAUSIA GIBBOIDES 



margin (proximal 2 considered coxal and distal 

 3 basal although segmentation is unclear); seta- 

 tion of medial lobes 1-5 progressing distally is 

 8-4-4-4-3; 2 setae on lobe 1 and 1 seta on lobes 

 2-4 situated submarginally on posterior face. 

 Endopod 1-segmented with 3 setae; exopod repre- 

 sented by 1 plumose seta on lateral margin. 

 There is no change in setation in calyptopis 

 phase. 



Maxilliped (Figure 9A) usually with 5 setae 

 on coxa, 4 marginal and 1 (sometimes absent) 

 on posterior face, 4(3) or 5( 17) setae were observed. 

 Basis Math 6 setae. Endopod 2-segmented; termi- 

 nal segment with 4 and proximal segment with 

 3 setae; 1 distal seta on basis and 1 on proximal 

 segment of endopod situated submarginally on 

 posterior face; 1 marginal seta on basis and 1 on 

 first segment of endopod relatively short and stout 

 with tiny marginal spinules. Exopod with 4 

 terminal setae and 1 proximal seta near in- 

 distinct articulation with basis. Fine marginal 

 hairs present as figured. 



Telson with 1 pair of lateral spines, 3 pairs 

 of posterolateral spines and 6 terminal spines, 

 posterolateral spine 3 (inner) slightly longer than 

 central posterolateral spine 2; terminal spines and 

 posterolateral spine 3 armed with spinules on 

 lateral margins, lateral spines and posterolateral 

 spines 1 and 2 with spinules on inner margins 

 only. 



Calyptopis II (Figure 2D) 



Calyptopis III (Figure 2E) 



Carapace with rudiment of small denticle on 

 posterolateral margin present in furcilia I (Figure 

 4A). Abdomen with 6 segments; 6th segment, 

 now separate from telson, with pair of biramous 

 uropods. 



Antennule (Figure 6F) with 3-segmented 

 peduncle, basal segment produced distally into 

 strong lateral spine extending to or slightly 

 beyond tip of inner ramus, inner margin of spine 

 setose. Peduncle segments 1-3 with 1-2-2 plumose 

 setae on inner margins; segment 3 with dorsal 

 lobe bearing 3 setae on distal margin; basal 

 segment with 1 large lateral seta at base of spine. 

 Inner flagellum about two-thirds length of outer 

 flagellum and may have 3rd terminal seta; other- 

 wise setation of rami unchanged. 



Mandible armature (Figure 71) unchanged. 



Maxillule with 7 setae on coxal endite and 5 

 spines on basal endite; no variation observed. 



Maxilla usually unchanged, with setation of 

 8-4-4-4-3 on lobes 1-5; lobe 3 varied with 3(1) or 

 4(20) setae and lobe 5 with 2(1) or 3(20) setae. 



Maxilliped (Figure 9B) usually with 6 setae on 

 coxa, 5(3) or 6(16) setae were observed. 



Uropod (Figure IIQ) biramous; protopod with 

 ventral spine above endopod; exopod with strong 

 posterolateral spine, 2 small spines and 2 setae 

 distally; endopod incompletely articulated with 

 protopod, bearing 1 spine and 2 setae distally 

 and 1 small subterminal dorsally projecting seta. 



Telson armature unchanged. 



Broad rostral hood of carapace with more 

 pronounced inward curve between eyes; dorsal 

 crest less prominent. Abdomen with 5 segments. 



Antennule (Figure 6E) biramous. Peduncle 

 unsegmented but may be constricted with seg- 

 mentation of calyptopis III visible beneath cuticle; 

 distal margin with 3 dorsal setae and inner 

 margin with 1 seta. Outer ramus with 2 aesthe- 

 tascs, 1-3 setae and 2-4 spines terminally; inner 

 ramus short, with 2 setae and 1-4 spines. 



Maxillule (Figure 8B) with 6(3) or 7(15) setae 

 on coxal endite; basal endite with 5 spines. 



Maxilliped with 4(1) or 5(19) setae on coxa. 



Telson, with addition of small median spine, 

 armed with 7 terminal spines; posterolateral 

 spine 2 now longest; lateral and posterolateral 

 spines with relatively large dorsal spinule slightly 

 more than halfway to tip. 



Furcilia I (Figures 3A, 4A) 



Eyes large, stalked and moveable, with 3-lobed 

 appearance due to arrangement of ommatidia 

 and concentrations of pigment as well as con- 

 strictions in cornea; lower lobe largest and most 

 distinctly defined; convex middle lobe especially 

 contributes to characteristic shape of eye. Cara- 

 pace emarginate behind eyes; rostrum broad, 

 blunt, fringed with small spines; posterior margin 

 produced into dorsal spine; posterolateral margins 

 with denticle; dorsal crest near midlength. First 

 segment of abdomen with pair of non-setose 

 pleopods; developing photophore between pleo- 

 pods sometimes with faint pigment. Small anal 

 spine present. 



Antennule (Figure 6G) with lateral spine of 

 peduncle segment 1 extending to distal margin 



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