endopodite. Proximal lobe (coxopodite) bears six 

 spinulose setae. Median lobe (basipodite) bears 

 five spinulose spines terminally. Unsegmented 

 endopodite originates from lateral margin of 

 basipodite and bears three terminal and two sub- 

 terminal spinulose setae. No outer seta on maxil- 

 lule. 



MAXILLA (Figure IF). — Exopodite (scaphog- 

 nathite) bears four long plumose setae and a prox- 

 imal seta; proximal end not projected posteriorly. 

 Endopodite unsegmented; bears eight setae. Both 

 basipodite and coxopodite bilobed. Basipodite 

 bears eight setae, four on each lobe. Coxopodite 

 bears 10 setae, three on distal lobe and seven on 

 proximal lobe. Most setae on basipodite and 

 coxopodite spinulose. 



FIRST MAXILLIPED (Figure IG).— Unseg- 

 mented protopodite bilobed; bears 14 setae. En- 

 dopodite four-segmented; setation formula 4, 1, 1, 

 3. Exopodite bears four natatory setae. No epipo- 

 dite. 



SECOND MAXILLIPED (Figure IH).— Un- 

 segmented protopodite not lobed; bears five setae. 

 Endopodite four-segmented; setation formula 

 5, 2, 0, 5. Exopodite bears five natatory setae. 



THIRD MAXILLIPED (Figure II).— Unseg- 

 mented protopodite not lobed; bears two setae. 

 Endopodite nearly as long as exopodite; five- 

 segmented; setation formula 4, 2,0, 1,2. Exopodite 

 bears five natatory setae. 



PEREOPODS (Figure IJ, K).— Only pairs one 

 to four present; pairs one and two (Figure IJ, K) 

 biramous, pairs three and four uniramous. All 

 pereopods poorly developed, unsegmented, and 

 compacted tightly under cephalothorax. 



PLEOPODS.— Absent. 



ABDOMEN AND TELSON (Figure lA, L).— 

 Abdomen consists of five somites (somite six is 

 fused with telson in Stage I). Third somite bears a 

 dorsal spine on posterior margin; fifth somite 

 bears pair of spines on posterolateral margin that 

 extend posteriorly about one-fourth length of fifth 

 abdominal somite. Telson emarginated distally; 

 bears 7 + 7 pairs of densely plumose setae. Minute 

 spinules at base of each seta, except possibly last 

 pair, and along posterior margin of telson to fourth 

 setal pair and on setae themselves. No anal spine. 



Comparisons of Zoeal Stage I With 

 Descriptions by Other Authors 



Of the published descriptions of Stage I zoeae of 

 Crangon spp. from the North Pacific Ocean, Stage 



I zoeae of C. franciscorum angustimana are most 

 similar to Stage I zoeae of C alaskensis, C. affinis, 

 C. septemspinosa, and Kurata's ( 1964) "Species A" 

 and "Species D." These examples are charac- 

 terized by a median dorsal spine on the posterior 

 margin of the third abdominal somite and by pos- 

 terolateral spines on the fifth abdominal somite. 



Stage I zoeae of C. alaskensis can be distin- 

 guished from Stage I C. franciscorum angus- 

 timana by the rostrum and pereopods. In Stage I C. 

 alaskensis the rostrum does not extend beyond the 

 eyes and the pereopods are absent (Loveland 

 1968), but in Stage I C. franciscorum angustimana 

 the rostrum extends beyond the eyes and the lar- 

 vae bear undeveloped pereopods 1-4. 



Stage I zoeae of C. affinis and "Species A" are 

 distinguished from Stage I zoeae of C. francis- 

 corum angustimana by the presence in Stage I 

 zoeae of C. affinis and "Species A" of a shallow 

 transverse groove in the carapace and two sub- 

 terminal setae along the outer margin of the an- 

 tenna! scale. Also in Stage I C. affinis and "Species 

 A," the endopodite of the third maxilliped is four 

 segmented. In Stage I zoeae of C. franciscorum 

 angustimana, the carapace does not have a shal- 

 low transverse groove; there is only one subtermi- 

 nal seta along the outer margin of the antennal 

 scale; and the endopodite of the third maxilliped is 

 five segmented. 



Stage I zoeae of Kurata's "Species D" are distin- 

 guished from Stage I zoeae of C. franciscorum an- 

 gustimana by the presence in Stage I zoeae of 

 "Species D" of a five-segmented endopodite on the 

 second maxilliped and pleopods that occur as dis- 

 tinct buds. In Stage I zoeae of C. franciscorum 

 angustimana, the endopodite of the second maxil- 

 liped is four segmented and there are no pleopod 

 buds. 



Stage I zoeae of C. septemspinosa are like Stage I 

 zoeae of C franciscorum angustimana with some 

 exceptions: the antennal scale of C septemspinosa 

 bears five plumose setae and the endopodite of the 

 first maxilliped is unsegmented (Needier 1941); 

 whereas, the antennal scale of C. franciscorum 

 angustimana bears 10 plumose setae and the en- 

 dopodite of the first maxilliped is four segmented. 



Tesmer and Broad (1964) described nine zoeal 

 stages of C. septemspinosa reared in the labora- 

 tory from ovigerous females obtained off Beaufort, 

 N.C. They found distinct morphological differ- 

 ences between their zoeae and zoeae of the same 

 species as described by Needier, especially in the 

 later stages. Based on Tesmer and Broad's descrip- 



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