HAYNES: PREZOEAE AND ZOEAE OF CHIONOECETES 



ANTENNA (FIGURE 2d).— Protopodite 

 (spinous process) of antenna elongate; slightly 

 shorter than rostral spine and armed with 

 numerous sharp spinules that increase in size 

 distally. Exopodite slender; less than one-half 

 length of protopodite; two setae near sharp 

 tip, each with two rows of many fine setules. 

 Endopodite (flagellum) rudimentary (repre- 

 sented by small protuberance near proximal 

 end of protopodite). 



MANDIBLES (FIGURE 2e).— Mandibles 

 without palps. Incisor composed of two large 

 pointed processes. A subterminal denticle that 

 arises from ventral side of mandible occurs 

 on molar process of right mandible but not on 

 left mandible. 



MAXILLULE (FIGURE 2f). — Endopodite 

 two segmented, with six setae on terminal 

 segment (arranged in pairs, one pair being 

 terminal) and one seta on distal end of basal 

 segment. Basal endite bears seven setae at 

 distal end (two setae are especially stout). 

 A bluntly pointed projection one-eighth the 

 height of nearest seta occurs between basal 

 endite setae and endopodite. Coxal endite bears 

 seven setae at distal end. All setae on maxillule 

 plumose. 



MAXILLA (FIGURE 2g). — Maxilla bears 

 large platelike exopodite (scaphognathite) with 

 11 (rarely 12) long, evenly spaced plumose 

 setae along outer margin and one longer and 

 thicker seta at proximal end. Endopodite only 

 slightly bifurcate; bears many fine hairs along 

 outer margin and three setae on each lobe. 

 There are two endites, both slightly bifurcate; 

 basal endite (distal) has five setae on each lobe, 

 and coxal endite (proximal) has four setae on 

 each lobe. All setae sparsely plumose except 

 those on exopodite, which are heavily plumose. 



FIRST MAXILLIPED (FIGURE 2h).— Ex- 

 opodite appears to have two segments but seg- 

 mentation not complete; four heavily plumose 

 segmented (natatory) setae on distal end. 

 Endopodite five segmented — setation formula 

 is 5, 2, 1, 2, 3. Basis has 10 setae along 

 posterior edge — setation formula is 3, 3, 2. 2. 



All setae except natatory setae sparsely plumose. 



SECOND MAXILLIPED (FIGURE 2i). — 

 Exopodite not completely segmented; four long, 

 heavily plumose segmented (natatory) setae 

 on distal end. Endopodite three segmented — 

 setation formula is 5, 1, 1. Basis has four setae 

 along posterior edge. All setae except natatory 

 setae sparsely plumose. 



THIRD MAXILLIPED (FIGURE 2a). — 

 Developing third maxilliped small, rudimentary, 

 and nonsegmented; tip bilobed. 



PEREIOPODS (FIGURE 2a). — Five de- 

 veloping pereiopods beneath carapace; they are 

 small, rudimentary, and not segmented or 

 bilobed. 



ABDOMEN AND TELSON (FIGURE 2j, 



1). — Abdomen consists of five segments and tel- 

 son (somite six is fused with telson in stage I). 

 Each segment has pair of hairs near dorsal 

 posterior margin; second and third segments 

 both have pair of slightly curved lateral knobs 

 — pair on third segment about half the length 

 of pair on second; pairs of long well-developed 

 spines, which become progressively shorter pos- 

 teriorly, on posterior lateral margin of third, 

 fourth, and fifth segments; those on third and 

 fourth segments extend beyond posterior mar- 

 gins of adjacent segments; those on fifth seg- 

 ment extend posteriorly to level of anus; lateral 

 spines may or may not have few minute hairs. 

 Telson bifurcate; furcations long, slender, and 

 finely spinulate and have upcurved tips; each 

 furcation bears three articulated telson setae on 

 inner side, a prominent spine laterally on outer 

 margin, a smaller dorsal spine posterior to 

 telson setae, and a minute spinule^ about midway 

 between the lateral and dorsal spines; lateral 

 and dorsal spines on furcations minutely spinu- 

 late. Each telson seta bears two rows of spinules, 

 and each row has two types of spinules. First 

 type short but wide at base, resembling row of 



3 The spinule was first described by Kurata (1963) 

 for C. o. elongiitits and is best seen in stained specimens 

 under high (400X) magnification. 



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