346 



FISHERY BULLETESr OF THE FISH AND WILDLIFE SERVICE 



pleopods and tlie telson as mentioned above. In 

 addition, the third mysis could be distinguished 

 by the presence of a rostral spine. 



A comparison of the corresponding stages in the 

 development of P. setiferus (based on Pearson's 

 work) and of P. duorarwm is presented in table 3. 

 The mysis stages were not included since they may 

 not be comparable in the two species. 



Table 3. — Corresponding stages in Penaeus duorarum and 

 P. setiferus 



[Dat» on P. setiferut from Peaison, 1939] 



Table 3. — Corresponding stages in Penaeus duorarum and 

 P. setlferus^ — Continued 



stage and struc- 

 ture 



NaupUus I: 



Length 



Width 



Ocellus 



Labnun... 



Antenna I 



Antenna II.. 



Mandible.. 



Caudal furcae 

 and spines. 



Setae 



NaupUus II: 



Length 



Width 



Ocellus 



Labrum... 

 Antenna I 



Antenna II.. 



Mandible 



Maxillae and 

 maillllpeds. 



Caudal furcae 

 and spines. 



Setae 



NaupUus III: 



Length 



Width 



Ocellus 



Labrum... 



Antenna I.. 



P. duoraTum 



0.35-0.40 mm 



0.18-0.20 mm 



Present 



Rounded, ventrally pro- 

 jecting; ends at level of 

 mandible. 



Unlramous and unseg- 

 mented; bears 2 lateral 

 and 3 "terminal" setae (2 

 terminal and 1 dorsal). 

 Bud of another terminal 

 seta present. 



Biramous and unseg- 

 mented. Endopod 

 bears 2 lateral and 2 

 terminal setae. Bud of 

 another terminal seta 

 present. Exopod bears 

 3 lateral and 2 terminal 

 setae. 



Biramous and unseg- 

 mented. Endopod and 

 exopod bear 3 terminal 

 setae each.' 



Furcae undeveloped. 

 Caudal end bears 1 pair 

 furcal spines. Dorso- 

 median spine present 

 near posterior end of 

 body. 



Smooth.. _ 



0.40-0.46 mm 



0.18-0.20 mm 



Present 



Same as NaupUus I 



Unsegmented. Bears 2 

 setae on anterolateral 

 and 1 on posterolateral 

 surface, and 3 terminal 

 setae. 



Unsegmented. Endopod 

 bears 2 lateral and 3 ter- 

 minal setae. Exopod 

 bears 3 lateral and 3 

 terminal setae. 



Same as NaupUus I 



Not observed. 



Furcal processes undevel- 

 oped. Caudal end stiU 

 bears 1 pair strong furcal 

 spines. 



Longer setae of append- 

 ages bear numerous 

 setules. 



0.46-0.49 mm 



0.17-0.20 mm 



Present ._ 



Same as in preceding 



stages. 

 Shows signs of segmenta- 

 tion. Bears 2 lateral 

 and 3 terminal setae. 



P. setiferus 



0.30-0.34 mm. 



0.16-0.20 mm. 



Present. 



Same as in P. duorarum. 



Unlramous and unseg- 

 mented; bears 2 lateral 

 and 3 terminal setae. 



Biramous and unseg- 

 mented. Endopod bears 

 2 lateral and 2 terminal 

 setae. Exopod bears 3 

 lateral and 2 terminal 

 setae. 



Same as In P. duorarum. 



Furcae and furcal spines 

 the same as in P. duora- 

 rum. No mention of 

 dorsomedian spine. 



Smooth. 



0.32-0.34 mm. 



0.16-0.18 mm. 



Present. 



Same as in NaupUus I. 



Same as in P. duorarum. 



Same as in P. duorarum. 



Same as In NaupUus I. 



Faint anlages of first and 

 second maxUUpeds ap- 

 pear posterior to mandi- 



SUght furcal processes, 

 each bears 1 strong and 

 1 weak furcal spine. 



Same as in P. duorarum. 



0.36-0.40 mm. 



0.14-0.16 mm. 



Present. 



Same as In precedingstages. 



Unsegmented. Setatlon 

 same as in P. duorarum. 



Stage and struc- 

 ture 



NaupUus ni-Con. 

 Antenna II 



Mandible 



MaxUlae and 



maxtUipeds. 

 Caudal fin-cae 

 and spines. 

 NaupUus IV: 



Length 



Width 



Frontal organs 



OceUus 



Labrum 



Antenna I 



Antenna II 



Mandible. . 



MaxUlac and 

 maxlUipeds. 



Caudal furcae 

 and spines. 



NaupUus V: 



lyength ___ 



Width.- _ 



Frontal organs. 



OceUus 



Labrum 



Carapace 



Antenna I 



Antenna II. 



Mandible.. 



P. duorarum 



Maxillae.. 



See footnote at end of table. 



MaxlUipeds.. 



Caudal furcae 

 and spines. 



Protozoea I: 



Body length.. 



Carapace 

 length. 



Unsegmented. Endopod 

 bears 2 lateral and 3 ter- 

 minal setae. Exopod 

 bears 3 lateral and 

 4 terminal setae. 



Same as in preceding 



Not observed. 



Well-developed. Each 

 furca bears 3 spines. 



0.48-0.65 mm 



0.18-0.20 mm... 



Absent? 



Present 



Pointed posteriorly 



Segmented. Bears 2 

 lateral and 3 terminal 

 setae. 



Endopod appears unseg- 

 mented and bears 2 

 lateral and 3 terminal 

 setae. Exopod hasabout 

 9 segments and bears 4 

 lateral and 4 terminal 

 setae. 



Swelling appears in base. 

 Endopod and exopod 

 unsegmented. Seta- 

 tlon same as in previous 

 stages. 



First and second maxUlae 

 and first and second 

 maxlUipeds appear ex- 

 temaUy on ventral sur- 

 face. Biramous; how- 

 ever, exopods of maxil- 

 lae knoblike. 



Bear 6 spines each 



0.63-0.61 mm 



0.17-0.20 mm 



Present 



Present _.. 



Large and pointed pos- 

 teriorly. 



Can be seen dorsaUy under 

 cuticle. 



Segmented; bears 3 setae 

 on anterolateral and 2 

 setae on posterolateral 

 surfaces; 3 terminal se- 

 tae. 



Endopod bears 3 lateral 

 and 4 terminal setae. 

 Exopod bears 6 lateral 

 and 4 terminal setae. 



SweUing at base of man- 

 dible pronounced; shows 

 spherical masticatory 

 surface. Endopod may 

 or may not be transpar- 

 ent due to lack of mus- 

 culature. 



Larger and biramous. Ex- 

 opods small and knob- 

 liie. Endopods bear 

 both terminal and lat- 

 eral setae. Second max- 

 illae larger than first. 



Larger and biramous. 

 Exopods typicaUy palp- 

 like and bear terminal 

 setae. Endopods bear 

 both terminal and lat- 

 eral setae. 



Each bears 7 spines. Buds 

 of barbs appear on longer 



0.86-1.02 mm. (reared 

 larvae). 0.98-1.14 mm. 

 (from plankton). 



0.40-0.49 mm 



P. ietiferus 



^ame as in P. duorarum. 



Sameasinpreceding stages. 



StUl under cuticle in mid- 

 line. 

 Same as in P. duorarum. 



0.38-0.44 mm. 



0.16-0.18 mm. 



Present. 



Present. 



Same as in P. duorarum. 



Same as In P. duorarum. 



Endopod may or may not 

 be segmented and bears 

 2 lateral and 3 terminal 

 setae. E.xopod has about 

 8 segments and bears 4 

 lateral and 4 terminal 

 setae. 



Same as in P. duroarum, 

 except that the endopod 

 appears to be segmented. 



First and second maxiUae 

 and first and second 

 maxlUipeds appear ex- 

 temaUy on ventral sur- 

 face. Biramous. 



Same as in P. duorarum. 



0.46-0.66 mm. 



0.16-0.20 mm. 



Present. 



Present. 



Same as in P. duorarum. 



Same as in P. duorarum. 



Same as in P. duorarum. 



Endopod bears 2 lateral 

 and 4 terminal setae. 

 Exopod bears 4 lateral 

 and 6 termin.ll setae. 



SweUing at base of man- 

 dible pronoimced; shows 

 spherical masticatory 

 surface. Endopod trans- 

 parent due to lack of 

 musculature. 



Larger and biramous. Pos- 

 sess sliort terminal .setae. 

 No other description 

 given. 



Larger and biramous. Pos- 

 sess short teimlnal setae. 



Each bears 7 spines. 



0.80-1.14 mm. 



0.46 mm. in first protozoea 

 with a body length of 

 0.86 mm. 



