HAYNES: DESCRIPTION OF PANDALUS HYPSINOTUS ZOEAE 



simple setae — one long, one short — occur be- 

 tween first and second pairs of spines. Two pairs of 

 simple setae (inner pair stouter) occur at base of 

 telson and project noticeably at nearly right 

 angles to telson surface (Figure 4A). Both pairs of 

 uropods nearly as long as telson and fully devel- 

 oped; both bear numerous small setae irregularly 

 located on dorsal and ventral surfaces of both 

 pairs in addition to setae figured. Beginning of 

 transverse hinge (diaeresis) of exopodite of uropod 

 faintly evident. 



STAGE V ZOEA 



40-44 plumose setae; proximal expansion of ex- 

 opodite and setae along its inner margin, espe- 

 cially proximal seta, considerably longer than in 

 previous stages. Endopodite shaped as adult; 

 bears three setae. Shape and setation of basipo- 

 dite and coxopodite similar to Stage IV except 

 distal lobe of basipodite bears 15 setae and 

 proximal lobe of coxopodite bears 7 long and 5 

 short setae. 



FIRST AND SECOND MAXILLIPED.— Simi- 

 lar to Stage IV except endopodite of first maxil- 

 liped bears two setae on second segment and 

 three or four on proximal segment. 



Total length of Stage V zoea (Figure 5A) 9.2 mm 

 (range 8.4-10.1 mm, 10 specimens). Numerous 

 small wine-red chromatophores occur primarily 

 on cephalothorax but also along surface of abdo- 

 men to base of telson and on dorsal hump of third 

 abdominal segment; large wine-red chromato- 

 phore on side of carapace especially pronounced; 

 yellow chromatophores few and minute; occur in 

 head region at base of antennae, on antennules, 

 and on dorsal surface of eyes. Rostrum similar in 

 shape to adult; 15-17 dorsal teeth, in addition to 1 

 (rarely 2) near acute tip; 4 or 5 ventral teeth. Still 

 no setae between dorsal rostral teeth (Figure 5A). 



ANTENNULE AND ANTENNA.— Essen- 

 tially similar to Stage IV. Inner flagellum of an- 

 tenna approximately 4 times length of scale. 



MANDIBLES.— Mandibles larger but mor- 

 phology unchanged from Stage IV; mandibular 

 palp row three segmented and bears three or four 

 setae terminally (Figure 5B). 



MAXILLULE (FIGURE 5C).— Maxillule adult 

 in shape. Endopodite bears one long seta termi- 

 nally, sometimes an additional short seta. Basipo- 

 dite bears 13 spines in two rows along terminal 

 margins: 5 of the spines are relatively long and 

 the remaining 8 short. Seventeen setae of various 

 lengths are distributed terminally and along 

 lateral margin of basipodite. Coxopodite bears 

 five long spinulose setae terminally and a row of 

 five shorter sparsely plumose setae extending 

 proximally; row of fine hairs and a medial seta 

 occur ventrally. 



MAXILLA (FIGURE 5D).— Maxilla more adult 

 in shape than previously. Exopodite fringed with 



THIRD MAXILLIPED.— Similar to Stage IV 

 except for a few additional setae, and exopodite is 

 reduced to remnant. Mastigobranchia similar in 

 shape to adult. Arthrobranchia small bud. 



FIRST PEREOPOD.— Appendage with few ad- 

 ditional setae and spines. Exopodite remnant, 

 distal joint of ischiopodite more pronounced than 

 in Stage IV (Figure 5E). Arthrobranchia minute 

 bud. Mastigobranchia on this and pereopods two 

 to four; adult in shape. 



SECOND PEREOPOD.— Exopodite remnant, 

 carpal joints of left and right pereopods 14-16 and 

 7. No arthrobranchia on this or remaining per- 

 eopods. 



THIRD, FOURTH, AND FIFTH PEREOPODS. 

 — Distal joints of carpal and basial segments 

 pointed (Figure 5F), no additional joint at basis. 

 Setation essentially as shown in Figure 3J except 

 carpopodite and meropodite each bear a spine. 



PLEOPODS (FIGURE 5A).— Pleopods bilobed, 

 segmented, and without setae. 



TELSON (FIGURE 5G).— Lateral margins 

 nearly parallel but slightly farther apart at 

 center and bear two spines on each margin. 

 Terminal margin straight; arrangement of spines 

 and setae on margin similar to Stage IV. The two 

 pairs of setae at base of telson noticeably longer 

 than in Stage IV. Transverse hinge of exopodite 

 of uropod complete; numerous small setae located 

 randomly on dorsal and ventral surfaces in 

 addition to those figured. 



337 



