FISHERY BULLETIN: VOL. 78, NO. 2 



Although there is variation in timing of events 

 with respect to stage, the form, setation, and de- 



TABLE 3. — Measurements (millimeters) of furcilia I-VI and 

 juvenile I in the northern form of Euphausia eximia. 



velopment of appendages are very similar in lar- 

 vae of congeners E. gibboides and E. eximia. The 

 descriptions with figures of E. gibboides larvae 

 (Knight 1975) may be consulted for morphology 

 and development of appendages of E. eximia 

 which are figured and discussed in detail here only 

 when necessary to contribute information specific 

 to.B. eximia. The setations of maxillule, maxilla, 

 and pleopods in larvae oiE. eximia are given in 

 Tables 4, 5, and 6. 



EGGS. — Perivitelline space relatively small, 

 50 spawned eggs with the following measure- 

 ments: Outer diameter, 0.38-0.46 mm; mean, 0.45 

 mm; SD, 0.02 mm. Perivitelline space, 0.03-0.07 

 mm; mean, 0.06 mm; SD, 0.01 mm. Eighty-five 

 eggs from the plankton differed slightly: Outer 

 diameter, 0.40-0.48 mm; mean, 0.45 mm; SD, 0.01 

 mm. Perivitelline space, 0.03-0.07 mm; mean, 0.05 

 mm; SD, 0.01 mm. 



NAUPLIUS I AND II.— Body ovoid, as figured 

 for E. gibboides, with one pair long posterior 

 spines in nauplius I and a second short outer pair 

 in nauplius II; both stages with 3 pairs of func- 



TABLE 4. — Development of maxillule in the northern form of Euphausia eximia; exopod with 4 setae and endopod with 2 



medial and 3 terminal setae in all stages; ( ) = usual condition. 



Stage 



Endopod 



Basal endite setae 



Pseudexopod 



Coxal endite setae 



Presence Anterior seta 



Calyptopis I 

 Calyptopis II- 

 Furcilia I 

 Furcilia II 

 Furcilia III 

 Furcilia IV 

 Furcilia V 

 Furcilia VI 

 Juvenile I 



7 



7 



8 



8 

 8-9(8) 

 8-9(9) 

 8-9(9) 

 9-10(9) 

 9-11(10) 



-/ + (+) 



+ 

 + 





 

 

 

 

 

 

 

 0-1 



Table 5. — Setation of maxilla in the northern form of Euphau- 

 sia eximia; medial lobe five with 3 setae in all stages; = usual 

 condition. 



tional appendages — antennule, antenna, and 

 mandible. Seven hatched nauplius I larvae with 

 the followdng dimensions: Length, 0.38-0.41 mm; 

 mean, 0.39 mm; SD, 0.02 mm. Width, 0.25-0.27 

 mm; mean, 0.26 mm; SD, 0.01 mm. 



METANAUPLIUS (FIGURES 2A, 3A).— 

 Rostral hood of carapace fringed with spines, 3 

 pairs on anterior margin relatively long, a fourth 

 anterolateral pair sometimes somewhat longer 

 than surrounding spines; usually 3 shorter spines 

 between medial pair of long spines, tiny spines 

 rarely interspersed; other small spines variable in 

 number. Dorsal crest high, rounded, with 2 small 

 spines (frequently broken or bent in preserved 



316 



