HAYNES: EARLY ZOEAL STAGES OF HIPPOLYTIDAE 



Antenna (Figure 3C). — Flagellum unsegmented, 

 shorter and narrower than scale, terminally has 

 plumose seta and shorter spinulose spine. Scale 

 distally divided into four joints, fringed with 11 

 heavily plumose setae. Small plumose seta about 

 midway on outer lateral margin. Protopodite with 

 spine at base of flagellum but not at base of scale. 



Mandibles (Figure 3D). — Well developed, with- 

 out palps. Incisor process of left mandible with 

 four teeth; incisor process of right mandible tri- 

 serrate. Left mandible has lacinia mobilis adja- 

 cent to incisor process and subterminal tooth on 

 truncated molar process. 



Maxillule (Figure 3E). — Coxopodite with eight 

 spinulose setae. Basipodite with 11 spinulose 

 spines terminally. Two-segmented endopodite 

 originating from lateral margin of basipodite 

 has five spinulose setae: three on distal segment, 

 two on proximal segment. Two setae especially 

 spinulose, as shown. No outer seta on maxillule. 



Maxilla (Figure 3F). — Scaphognathite with four 

 long plumose setae, slightly longer thicker seta at 

 proximal end, and series of fine hairs along inner 

 margin of exopodite. Unsegmented endopodite 

 with nine setae (four spinulose, as shown). Both 

 basipodite and coxopodite bilobed. Basipodite 

 with 17 setae: 8 on distal lobe, 9 on proximal lobe. 

 Coxopodite with 14 setae: 4 on distal lobe, 10 on 

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

 and coxopodite setulose. 



First maxilliped (Figure 3G). — Unsegmented 

 protopodite with 20 setae; most setae heavily 

 spinulose. Endopodite four-segmented; setation 

 formula 4, 2, 1, 4; series of fine hairs on medial 

 margin of proximal segment. Four natatory setae 

 on exopodite. Epipodite, a small lobe. 



Second maxilliped (Figure 3H). — Unsegmented 

 protopodite with seven spinulose setae. Endopo- 

 dite four-segmented; setation formula 6, 2, 1, 2. 

 Exopodite about three times longer than endopo- 

 dite, five natatory setae. 



Third maxilliped (Figure 31). — Usually one seta 

 on unsegmented protopodite. Endopodite five- 

 segmented, seven setae: five setae on distal, two 

 on penultimate segment. Exopodite with five 

 natatory setae. 



Pereopods. — Poorly developed, unsegmented, and 

 compacted tightly under cephalothorax. Pairs 1-3 

 biramous, 4 and 5 uniramous. 



Pleopods. — Absent. 



Abdomen and telson (Figure 3A, J, K). — Five 

 somites and telson (somite 6 fused with telson). 

 Fifth somite with pair of spines on posterolateral 

 margin that extend posteriorly about one-fifth 

 length of fifth somite. Minute spinules along 

 posterodorsal border of fifth somite (Figure 3J) 

 (spinules most easily seen in cleared specimens at 

 sslOOx magnification). Telson (Figure 3K) slight- 

 ly emarginate distally, bears 7 -t- 7 densely 

 plumose setae. Third setal pair shorter than 

 second or fourth setal pair. Minute spinules along 

 posterior margin and at base of all setal pairs 

 except possibly outer (seventh) setal pair. En- 

 closed uropods visible. Anal spine present. 



Eualus suckleyi — Stage II Zoeae 



Mean total length of Stage II, 3.8 mm (range 

 3.5-4.2 mm, 8 specimens). Eyes stalked. Rostrum 

 shaped as in Stage I. Carapace with small supra- 

 orbital spine, no spinules (Figure 4A). 



Antennule. — Similar to Stage I, except peduncle 

 two-segmented with two setae at joint. 



Antenna. — Flagellum with terminal spine, no 

 setae, almost same length as scale (Figure 4B). Tip 

 of scale four-segmented, proximal segment incom- 

 plete. Scale with 13 plumose setae — no proximal 

 seta near outer lateral margin. 



Mandibles, maxillule, and maxilla. — Same as 

 Stage I. 



Maxillipeds. — Epipodite of first maxilliped dis- 

 tinctly lobed. Exopodites of maxillipeds 1, 2, 

 and 3 have four, five, and five natatory setae, 

 respectively. 



Pereopods. — Poorly developed, tightly compacted 

 under cephalothorax; pairs 1-3 biramous, 4 and 5 

 uniramous. 



Pleopods. — Absent. 



Abdomen and telson. — Somite 6 fused with tel- 

 son. Abdomen retains spines on fifth somite. 



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