SCOTTO LARVAL DEVELOPMENT OF CUBAN STONE CRAB 



Antenna (Figure 5E). Exopodal spine extending 

 (as in stage IV) beyond distal tip of protopodal 

 process and remaining 0.75 y length of exopodite. 

 Endopodal bud elongate, unsegmented, about 

 0.7 * length of protopodal process. 



Mandible (Figure 5F). Palp bud now present on 

 anterior surface. Left molar process with 4 or 5 

 rounded to angular prominences along margin of 

 inner angle and junction with incisor process, 

 right molar process with 2 or 3 prominences. 



Maxillulc (Figure 5G). Endopodite unchanged. 

 Lateral margin of basal endite with 2 long feath- 

 ery setae; usually 8(8-10) spines and 8(8-10) setae 

 terminally; coxal endite with 6 strong plus 5 thin- 

 ner setae distally and 1 long feathery seta basally. 



Maxilla (Figure 5H). Endopodite unchanged; 

 basal endites with 7,7 processes; coxal endite lobes 

 with 8 or 9, and 4 or 5 processes, respectively. 

 Scaphognathite with 36-45 plumose setae. 



Maxilltped 1 ( Figure 6A). Coxopodite with 5 ( 5 or 

 6) setae; basi- and endopodal setae unchanged. 

 Exopodite with usually 11 distal plus 1 lateral 

 natatory setae. 



Maxilliped 2 (Figure 6B). Coxopodite with 1 

 seta; basi- and endopodal setae unchanged. 

 Exopodite with 12 distal and commonly 1 smaller 

 lateral setae. 



Maxilliped 3 (Figure 6C). Exopodite two- 

 segmented, distal segment with up to 6 terminal 

 setae of variable length; endopodite indistinctly 

 four- or five-segmented; unsegmented naked 

 epipodite now present, commonly with 1 seta. 



Color. Cephalothorax and abdominal coloration 

 similar to fourth stage. Placement artd color of 

 chromatophores unchanged except for additional 

 orange chromatophore at the posterior margin of 

 the yellow telson. In lateral view, abdomen gold 

 dorsally, brown medially, and orange ventrally; 

 pleopods colorless carapace rose-gold dorsally, 

 brown medially, rose posteroventrally, and brown 

 anteroventrally. Ommatidia light rose through- 

 out but concentrated dorsally; cornea reflecting 

 emerald green to irridescent turquoise depending 

 on the position of the larvae. Mandibles and lab- 

 rum dark brown; antennules and antenna color- 

 less. On the first day in stage V, chelae barely 



visible and colorless except for dark brown 

 chromatophores on the interior margin of each 

 manus. Chelae progressively turn deep orange- 

 rose and continue to extend beneath the carapace 

 by the fourth day. 



Fifth Zoeae (penultimate) 



Number of specimens examined: 10. 



Remarks: Penultimate fifth stage zoeae 

 molted to an atypical sixth stage before molt- 

 ing to megalopae. The morphological charac- 

 ters compared and discussed below are the 

 ones that differ from the regular fifth stage 

 and may be used as a guide to distinguish 

 between the two fifth stages. The abdominal 

 setation should be one of the first characters to 

 check in distinguishing between the two fifth 

 stages. 



Carapace. Carapace similar to ultimate fifth 

 stage zoeae. Setation on the posterolateral border 

 of penultimate fifth stage zoeae 15 or 16 (15-20 in 

 ultimate stage). 



Abdomen. First abdominal somite usually with 

 8 (7-10) dorsal setae (10 in ultimate stage). 



Antennule. Endopodal bud less developed, its 

 distal tip not extending beyond the midpoint be- 

 tween the base of the first tier of aesthetascs and 

 the base of the bud itself (ultimate stage bud ex- 

 tends about one-fourth past this midpoint). Aes- 

 thetascs arranged in tiers: progressing distally 

 3-7,7,1,5 ( the ultimate stage proximal tier usually 

 has 7 aesthetascs). 



Antenna. Endopodal bud less elongate, often not 

 reaching distal end of protopodal spinules, never 

 surpassing them (as in ultimate stage). 



Mandible. Palp bud smaller in penultimate 

 stage, other prominences equal in both fifth 

 stages. 



Maxilliped 1 . Coxopodite with 4 setae (5 in ulti- 

 mate stage). Exopodite with either 1 1 or 1 1 plus 1 

 natatory setae (latter condition usual in ultimate 

 stage). 



Maxilliped 2 . Exopodite exhibits either 12 or (as 

 usual in ultimate stage) 12 plus 1 natatory setae. 



369 



