HAYNES: EARLY ZOEAL STAGES OF HIPPOLYTIDAE 



of right mandible. Lacinia mobilis adjacent to 

 incisor process and subterminal tooth on left 

 mandible; neither structure on right mandible. 



Maxillule (Figure IE). — With coxal and basial 

 endites and endopodite on maxillule (first max- 

 illa). Eight setae, all spinulose, on proximal 

 lobe (coxopodite). Fifteen spines terminally (four 

 spines spinulose) on median lobe (basipodite). 

 Two-segmented endopodite on lateral margin of 

 basipodite: distal segment with four, sometimes 

 three, spinulose setae terminally (one seta espe- 

 cially long; remaining three, or two, about equal 

 length); two spinulose setae terminally on prox- 

 imal segment. No outer seta on maxillule. 



Maxilla (Figure IF). — Platelike exopodite (sca- 

 phognathite) with 25 long plumose setae and long 

 thicker seta at proximal end. Both coxopodite and 

 basipodite bilobed. Ten setae on unsegmented 

 endopodite — all setae distinctly setulose. Basipo- 

 dite with 23 setae: 11 on distal lobe, 12 on proximal 

 lobe. Most, if not all, setae on basipodite and 

 coxopodite setulose. Sixteen setae on coxopodite: 

 4 on distal lobe, 12 on proximal lobe. 



First maxilliped (Figure IG). — Unsegmented pro- 

 topodite with 31 spinulose setae: 23 on basipodite, 

 8 on coxopodite. Endopodite four-segmented; seta- 

 tion formula 4, 3, 2, 6. Exopodite segmented at 

 base, has four natatory setae. Epipodite a single 

 lobe. 



Second maxilliped (Figure IH). — Seven sparsely 

 spinulose setae on unsegmented protopodite. 

 Endopodite five-segmented; fourth segment ex- 

 panded somewhat laterally; setation formula 5, 4, 

 2, 3, 3. Exopodite about three times longer than 

 endopodite, not segmented at base. Five natatory 

 setae on exopodite. No epipodite. 



Third maxilliped (Figure II). — Two simple setae 

 on unsegmented protopodite. Endopodite five- 

 segmented, nearly as long as exopodite; setation 

 formula 5, 5, 1, 3, 2. Setae simple and, except for 

 few terminal setae, minutely spinulose. Exopodite 

 unsegmented at base, has five natatory setae. 

 No epipodite. 



First pereopod (Figure IJ). — Endopodite relative- 

 ly short, wide, unsegmented; chela partially 

 formed; dactylopodite with simple spine. Exopo- 

 dite, a small lobe. 



Second pereopod. — Similar to first pereopod 

 except narrower, exopodite smaller, and chela 

 more deeply cleft. 



Third (Figure IK), fourth, and fifth pereopods. — 

 Nearly identical, except size decreases slightly 

 from third to fifth pair. No exopodites. 



Pleopods. — First pleopod (Figure ID blunt, 

 slightly bilobed. Second pleopod (Figure IM) bi- 

 lobed; inner lamella with bud of appendix interna. 

 Third, fourth, and fifth pleopods same as second 

 pleopod. All pleopods without joints or setae. 



Abdomen and telson (Figure lA, N). — Five so- 

 mites and telson (somite 6 fused with telson). 

 Fourth and fifth abdominal somites with pair of 

 posterolateral spines about half as long as the 

 somites themselves — pair on fifth somite slightly 

 shorter than pair on fourth somite. Telson slightly 

 emarginated distally, has 9 + 9 densely plumose 

 setae; small spinules between bases of all setae 

 except last outer pair of setae. Enclosed uropods 

 visible. Anal spine present but minute. 



hebhe lis polar is — Stage II Zoeae 



Mean total length of Stage II, 5.7 mm (range 5.6- 

 5.8 mm, 4 specimens). Rostrum (Figure 2A) styli- 

 form, not sinuate, without teeth, about one-half 

 length of carapace. Carapace with small supra- 

 orbital spine and pterygostomian spine; no spi- 

 nules along posteroventral margin. Eyes stalked. 



Antennule (Figure 2B). — Similar to Stage I an- 

 tennule, except heavily plumose seta arises from 

 small conical projection. Spine, or seta, and four 

 aesthetascs on tip of large conical projection. 

 Three plumose setae ventrally on distal portion 

 of peduncle. 



Antenna (Figure 2C). — Flagellum of antenna 

 three-segmented: terminal segment spined at tip; 

 proximal segment has simple seta. Scale and 

 protopodite similar to scale and protopodite of 

 Stage I. 



Mandibles, maxillule, and maxilla. — Nearly 

 identical to Stage I, except molar process of left 

 mandible has several spines along outer margin. 

 Eighteen setae on basipodite of maxillule; 12 setae 

 on coxopodite of maxillule. About 30 setae on 

 scaphognathite of maxilla. 



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