GORE and SCOTTO: LARVAL DEVELOPMENT OF CYCLOCRAPSUS INTEGER 



Remarks. — The penultimate fifth stage zoea 

 molted to a sixth stage before metamorphosing 

 to megalopa. Only morphological features differ- 

 ing significantly from the ultimate fifth stage, 

 which molts directly to megalopa, are discussed 

 below. 



Antennule (Fig. 6C). — No endopodal bud present, 

 5 terminal plus 4 subterminal unequal aesthe- 

 tascs present. 



Antenna (Fig. 6D).— Endopodal bud only one- 

 half length of protopodal process, other arma- 

 ture and processes similar. 



Mandible. 

 similar. 



-No palp present, other armature 



Abdomen. — Pleopod buds without endopodites, 

 less elongate and developed. 



Sixth Zoea 



Carapace length: 1.3 mm; 3 specimens exam- 

 ined. 



Remarks.— The sixth stage zoea appear similar 

 in form and armature to the ultimate fifth stage. 

 Only morphological characters which may be 

 used to distinguish between the two stages are 

 discussed below. 



Carapace. — Little inflated, posterodorsal border 

 with 6 setae. 



Abdomen and Telson. — First somite with 8 or 9 

 middorsal setae, pleopod buds more elongate. 



Antennule (Fig. 6G). — Aesthetascs arranged in 

 tiers as illustrated, progressing distally 2,2,4,4. 



Antenna (Fig. 6H). — Endopodal bud obscurely 

 segmented, five-sixth length of protopodal pro- 

 cess. 



Mandible. — Palp more elongate. 



Maxillule. — Basal endite with 18 setae, coxal 

 endite with 12 setae, basal margin with 3 or 4 

 plumose setae. 



Maxilla. — Basal endites with 9,8, coxal with 12,4 

 setal formulae. Scaphognathite with 34-37 mar- 

 ginal setae. 



Maxilliped /.— Coxopodite with 4 or 5 ventral 

 setae. Basipodite setal formulae variable from 9 

 to 11 ventral setae, exopodite with 12 or 13 nata- 

 tory setae. 



Maxilliped £— Coxopodite naked or with 1 seta 

 ventrally, endopodite setation variable either 

 0,1,5+1 or 1,1,5+1. Exopodite with 13 or 14 nata- 

 tory setae. 



Maxilliped 3.— Trilobed as in fifth stage, may 

 have 1 seta on each lobe. 



Color.— Similar to fifth stage, innumerable spi- 

 dery brown and orange chromatophores, entire 

 maxillipeds now orange brown. 



Megalopa 



Carapace length X width: 

 specimens examined. 



1.45 X 1.25 mm: 7 



Remarks. — Megalopae molting from both fifth and 

 sixth zoeal stages are similar in form and arma- 

 ture. Morphological characters distinguishing 

 megalopae, which molted from ZVI, are placed 

 in brackets under the appropriate headings. 



Carapace (Fig. 7A, B).— Cephalothorax sub- 

 quadrate, laterally inflated. Smooth surface cov- 

 ered with hairs as illustrated, plus innumerable 

 setae on posterior and posterolateral borders. 

 Frontal region developed into ventrally de- 

 flexed, bluntly rounded rostrum with distinct 

 median cleft, appearing as U-shaped sinus 

 viewed dorsally. Anterolateral margins of cara- 

 pace produced into 2 indistinctly rounded lobes. 

 Eyes large, projecting laterally. 



Abdomen and Telson (Fig. 7A, a, E-I).— Somites 

 1-5 with bluntly rounded posterolateral pro- 

 cesses, somite 6 much broader than long; all with 

 setae as illustrated; telson semicircular, no pos- 

 terior marginal setae, 2 pairs medially, others as 

 illustrated. Pleopods well developed, with vari- 

 able setation 16-19, 20 or 21, 19-22, 22 [19-21, 21, 

 22, 22], all endopods with 3 hooked setae termi- 

 nally. Uropods with 10 or 11 exopodal plus 1 pro- 

 topodal seta [11 or 12 plus 1]. 



Pereopods (Fig. 7A, C, D).— Chelipeds well de- 

 veloped, somewhat inflated, unarmed, equal, 

 shorter than walking legs, gape of chelae irregu- 

 larly serrated, setae on remaining articles as 



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