KNIGHT: DEVELOPMENT OF EUPHAUSIA GIBBOIDES 



0.1 mm 



Figure 1. — Nauplius I: A, dorsal view. Nauplius II: B, dorsal view. Metanauplius: C, dorsal view; D, lateral view. 



margins constricted behind eyes; posterior margin 

 produced into strong dorsal spine; dorsal crest 

 prominent. Compound eyes widen as they develop 

 during stage, striated body of photophore visible. 

 Thoracic segments may be visible; abdomen 

 unsegmented. 



Antennule (Figure 6D) 2-segmented, basal 

 segment with 2 dorsal setae, 1 medial seta, 

 and medial spine on distal margin; small terminal 

 segment with 2 aesthetascs, 3 setae, 1 strong 

 medial spine and tiny spine. 



Antenna (Figure 7D) with 2-segmented proto- 

 pod. Exopod wdth 7 setae on 5 distal segments; 

 terminal segment wdth 3 setae, subterminal seg- 

 ments with 1 seta each. Endopod with 4 terminal 

 setae and 2 setae on inner margin, the proximal 



marginal seta may be rudimentary; in addition 

 to setules, distal marginal seta and 2 terminal 

 setae bear small spinules and 3rd terminal seta 

 armed with proximal row of comblike setules. 

 This setation remains unchanged until furcilia V. 



Mandibles (Figure 7H) asymmetrical; both with 

 narrow plate near pars molaris and tuft of setae 

 at base of plate; right mandible with dentate 

 process near incisor teeth; when mandibles close 

 dentate process bends inward toward mouth, 

 the lower plates overlap. Conical anterolateral 

 process and small prominent lateral knob pres- 

 ent; lateral knob disappears in furcilia I, and 

 anterolateral process decreases in size gradually 

 up to late furcilia stages. 



Maxillule (Figure 8A) with 6(1) or 7(20) setae 



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