HAYNES: EARLY ZOEAL STAGES OF HIPPOLYTIDAE 



Pleopods. — Absent. 



Abdomen and telson. — Pair of lateral spines on 

 fourth and fifth somites. Lateral spines on fourth 

 somite slightly smaller than lateral spines on fifth 

 somite (Figure 5). Minute spinules on postero- 

 dorsal margin of fourth and fifth somites: usually 

 one to three on fourth somite, about eight on fifth 

 somite. Minute spinules somewhat variable in 

 size and number, slightly larger than spinules of 

 E. suckleyi. Telson same as Stage I telson of 

 E. suckleyi. 



Stage II Zoeae 



Mean total length of Stage II, 4.1 mm (range 

 4.0-4.3 mm, 10 specimens). Carapace with two 

 spinules immediately posterior to pterygostomian 

 spine; small supraorbital spine present. 



Antennule and antenna. — Similar to Stage II 

 E. suckleyi, except antennules have only 1 small 

 seta at joint of peduncle and scale with 16 or 17 

 plumose setae. 



Mandibles, maxillule, and maxilla. 

 Stage I E. fabricii. 



-Same as 



Maxillipeds. — Exopodites of maxillipeds 1, 2, and 

 3 have 4, 9, and 10 natatory setae, respectively. 

 Epipodite on first maxilliped undeveloped, not 

 lobed. 



0. 5 mm 



Figure 5. — stage I zoea of Eualus fabricii: fourth and fifth 

 abdominal somites, right side. 



Pereopods. — Pairs 1-3 biramous, 4 and 5 uni- 

 ramous. 



Pleopods. — Absent. 



Abdomen and telson. — Fourth and fifth somites 

 with lateral spines, no spinules. Telson fused with 

 sixth somite, has 8 + 8 densely plumose setae. 

 Setae noticeably shorter than in Stage I E. fabricii. 

 Uropods enclosed. 



Spirontocaris arcuata — Stage I Zoeae 



Mean total length of Stage I (Figure 6A), 4.2 mm 

 (range 4.1-4.4 mm, 10 specimens). Rostrum (Fig- 

 ure 6B) spiniform, without teeth, about one- 

 seventh length of carapace, projects downward 

 paralleling contour of eyes. Carapace with small, 

 somewhat angular, dorsal prominence at base of 

 rostrum; another prominence near posterior edge. 

 Pterygostomian spines present, not hidden by 

 sessile eyes. Two or three minute spines along 

 anteroventral margin of carapace. No supraor- 

 bital spines. 



Antennule (Figure 6C). — Unsegmented peduncle 

 with conical projection and several small simple 

 setae (one seta especially longer than others). 

 Four aesthetascs on small projection on peduncle 

 near base of conical projection. 



Antenna (Figure 6D). — Unsegmented flagellum 

 shorter and narrower than scale. Flagellum with 

 spinulose apical spine and several simple setae of 

 various lengths. Scale distally divided into four 

 segments, fringed with 11 heavily plumose setae, 

 has small plumose seta proximally (near outer 

 lateral margin). Protopodite with spine at base of 

 flagellum but not at base of scale. 



Mandibles (Figure 6E). — Well developed, with- 

 out palps. Incisor process of left mandible has four 

 teeth; incisor process of right mandible triserrate. 

 Left mandible with relatively wide lacinia mobilis 

 adjacent to incisor process, subterminal tooth on 

 truncated molar process. 



Maxillule. — Maxillule same shape as maxillule of 

 Stage I E. suckleyi (Figure 3E). Coxopodite with 

 seven spinulose setae. Basipodite with 10 (some- 

 times 11) spinulose spines terminally. Endopodite 

 two-segmented, has five spinulose setae: three on 



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