COOK and MURPHY: DEVELOPMENTAL STAGES OF BROWN SHRIMP 



golden brown, with the appendages tinged red 

 apically. The translucent body appears filled 

 with small granules that flow freely when the 

 cuticle is ruptured. 



Three pairs of appendages are present. The 

 first antennae are uniramous and slightly less 

 than three-quarters the length of the body. Each 

 second antenna is biramous, its endopod slightly 

 shorter than the exopod, and approximately 

 three-quai'ters the body length. The mandibles 

 are biramous and slightly less than one-half the 

 body length. 



In this substage all setae are smooth, but in 

 subsequent substages, the longer ones are plu- 

 mose. 



Setation of appendages: 



First antenna: Two short ventrolateral; 

 two long terminal plus a 

 small spike; one long 

 dorsolateral. 

 Second antenna: 



Endopod: Two short ventrolateral; 

 two long terminal plus a 

 small spike. 

 Exopod: Three long ventrolateral; 



two long terminal. 

 Mandible: Both branches bear three 



long setae. 



NAUPLIUS II 



(Fig- 3) 



Mean TL = 0.39 mm (0.36-0.41 mm) 



Mean W = 0.20 mm (0.20-0.21 mm) 



N = 27 



Body shape is similar to that of the first 

 nauplius except that the posterior end is no 

 longer rounded; the portion between the single 

 pair of furcal spines has become straightened. 

 The small dorsomedian spine near the posterior 

 end (present in the first substage) is absent 

 in this substage. 



Setation of appendages: 



First antenna: One short and one medium 

 ventrolateral; one short, 

 one medium, and one 

 long terminal ; one me- 

 dium dorsolateral. 



Figure 3. — Nauplius II, ventral view. 



Second antenna: 



Endopod: Two short ventrolateral; 

 one small spike and two 

 long terminal. 

 Exopod: Three long ventrolateral; 



two long and one short 

 terminal. 

 Mandible: Same as Nauplius I. 



NAUPLIUS III 



(Fig. 4) 

 Mean TL = 0.40 mm (0.36-0.43 mm) 

 Mean W = 0.21 mm (0.20-0.23 mm) 



N = 51 



The posterior portion of the body is more 

 elongate than in previous substages, but the 

 shape remains essentially the same. The body 

 is slightly depressed between the two developing 

 furcal processes, each of which bears four 

 spines. The small dorsomedian spine, absent 

 in the second nauplius, reappears. The begin- 

 nings of ventral appendages can be seen as small 

 indentations posterior to the labrum. The bases 

 of the mandibles have become slightly swollen, 

 and small frontal organs are present at the an- 

 terior end of the body. 



Setation of appendages: 



First antenna: One short and two medium 

 ventrolateral; one short, 

 one medium, and one 



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