KEY TO GENERA OF PENAEID LARVAE 

 AND POSTLARVAE 



PROTOZOEAE 



(Fig. 5) 



1 Number of lateral setae on endopod of second 



appendage 1 + 1+2 2 Penaeus 



Number of lateral setae on endopod of second 

 appendage not 1 + 1+2 2 



2(1) First appendage about twice as long as second; no 

 spine on anterior margin of labrum; number of 

 lateral setae on .endopod of second appendage 

 1+2 + 3 Sicyonia 



2 Starting with proximal seta, the number of lateral setae at each point of 

 insertion is recorded. 



First and second appendages of nearly equal 

 length; a spine present on anterior margin of 

 labrum; number of lateral setae on endopod of 

 second appendage may be 1 + 2 + 3 3 



3(2) Number of lateral setae on endopod of second ap- 

 pendage 1+2+2, 1 + 2 + 3, or2 + 2 + 2_ Parapenaeus 

 Number of lateral setae on endopod of second ap- 

 pendage not 1 + 2 + 2 or 2 + 2 + 2 4 



4(3) Number of lateral setae on endopod of second 



appendage 2 + 2 + 3 Solenocera 



Number of lateral setae on endopod of second 

 appendage 2 + 2 5 



5(4) Four long, terminal setae on endopod of second 



appendage Trachypeneus 



Four long and one short terminal setae on endopod 

 of second appendage Xiphopene us 



\ 



-.i'l.'.tvf. 1 



Figure 5. — Penaeid protozoeae: a, Parapenaeus, Protozoea I: b, Penaeus, Protozoea I; c, Sicyoma, Protozoea I; </, 

 Solenocera, Protozoea I; e, Solenocera, Protozoea 11;/, Trachypeneus, Protozoea I; 17, Xiphopeneus, Protozoea I. 



442 



U.S. FISH AND WILDLIFE SERVICE 



