Choi and Hong: Larval development of Metapenaeopsis dale i 
279 
Antennule (Fig. 2A): Uniramous; three terminal and 
three lateroventral setae. 
Antenna (Fig. 2A): Biramous; endopod with three termi- 
nal and two lateroventral setae; exopod with three termi- 
nal and four lateroventral setae. 
Mandible (Fig. 2A): Biramous; protopodal part swollen; 
endopod and exopod each with two terminal and one lat- 
eroventral setae; coxal part enlarged. 
Fifth naupliar stage (Fig. 2, C and D) 
Size TL: 0.41 mm (0.34-0.54 mm; SD=0.07; 72 = 10) 
BW: 0.18 mm (0.14-0.23 mm; SD=0.03; n = 10) 
Body (Fig. 2, C and D): Slightly more elongate, tapering 
towards telson lobes; anteroventral median ocellus; cara- 
pace rudimentary; buds of the oral appendages appeared. 
Antennule (Fig. 20: Uniramous; segmentation rudi- 
mentary; two terminal and two lateroventral setae. 
Antenna (Fig. 20: Biramous; segmentation rudimentary; 
endopod with three terminal and two lateroventral setae; 
exopod with four terminal and five lateroventral setae. 
Mandible (Fig. 20: Biramous; protopod bulbous; seta- 
tion unchanged. 
Telson (Fig. 20: Bilobed with 6+6 setae. 
Sixth naupliar stage (Fig. 2, E and F) 
Size TL: 0.56 mm (0.53-0.58 mm; SD=0.01; /? = 15 ) 
BW: 0.24 mm (0.23-0.26 mm; SD=0.01; 22=15) 
Body (Fig. 2, E and F): Elongate with distinct waist; an- 
teroventral median ocellus; carapace developed; rudimen- 
tary maxillae and maxillipeds bearing numerous short 
setae. 
Antennule (Fig. 2E): Uniramous; 11-segmented with 0, 
0, 0, 0, 0, 1, 0, 1, 0, 2, 4 setae. 
Antenna (Fig. 2E): Biramous; peduncle two-segmented; 
endopod four-segmented with 0, 1, 1, 4 setae; exopocl 
10-segmented with 0, 0, 1, 2, 1, 1, 1, 1, 1, 3/4 setae. 
Mandible (Fig. 2E): Unchanged. 
Telson (Fig. 2E): Bilobed with 7+7 setae of varying sizes. 
First protozoeal stage (Fig. 3, A-l) 
Size TL: 1.07 mm (0.97-1.23 mm; SD=0.09; n=10) 
Cephalothorax (Fig. 3A): Incompletely and loosely cov- 
ered by unarmed carapace; carapace round to oval, with 
shallow posterior median notch, anterior margin with one 
pair of orbital spines; rostrum absent; paired sessile com- 
pound eyes. 
Antennule (Fig. 3B): Uniramous; six-segmented with 0, 
0, 0, 0, 4, 6 (three aesthetascs) setae. 
Antenna (Fig. 30: Biramous; protopod two-segmented; 
endopod two-segmented with 5, 5 setae; exopod 10-seg- 
rnented with 0, 0, 1, 2, 1, 2, 1, 1, 1, 3 setae. 
Mandible (Fig. 3D): Endopod and exopod absent; asym- 
metrical; masticatory surface with lower molar processes 
and upper curved incisor processes; molar with many 
small teeth; incisor with 2-4 larger teeth; left and right 
mandible each with one denticulated tooth. 
Maxillule (Fig. 3E): Biramous; protopod two-lobed, coxal 
endite with eight setae, basal endite with two stout setae 
and two setae; endopod three-segmented with 3, 2, 5 setae; 
small exopod with four plumose setae. 
Maxilla (Fig. 3F): Biramous; protopod five-lobed, endites 
with 8, 3, 3, 3, 3 setae; endopod four-segmented with 2, 2, 
2, 3 setae; exopod with five plumose setae. 
First maxilliped (Fig. 3G): Biramous; protopod partially 
divided, coxa with six setae, basis with nine setae; endo- 
pod four-segmented with 3, 2, 2, 5 setae; exopod with seven 
plumose setae. 
Second maxilliped (Fig. 3H): Biramous; protopod two- 
segmented, coxa without setae, basis with four setae; en- 
dopod four-segmented with 2, 2, 2, 5 setae; exopod with 
five plumose setae. 
Third maxilliped (Fig. 31): Undeveloped biramous; exo- 
pod with two plumose setae. 
Post-carapacial region (Fig. 3A): Six thoracic and one free 
abdominal somites; unsegmented abdomen with forked 
telson. 
Telson (Fig. 3A): Broadly bifurcated in two lobes with 
seven pairs of plumose setae. 
Second protozoeal stage (Fig. 4, A-l) 
Size TL: 1.58 mm (1.44-1.83 mm; SD=0.14; 22=17) 
CL: 0.50 mm (0.40-0.60 mm; SD=0.05; 22=17) 
Cephalothorax (Fig. 4A): Loosely covered by carapace; 
carapace armed with long acute rostrum and two pairs of 
supraorbital spines; rostrum present and exceeding eye; 
eyes stalked. 
Antennule (Fig. 4B): Uniramous; seven-segmented with 
0, 0, 0, 0, 1, 4, 6 (three aesthetascs) setae. 
Antenna (Fig. 40: Biramous; protopod two-segmented 
with 0, 1 setae; unchanged; exopod 10-segmented with 0, 
1,2, 1,2, 1, 1, 1, 1,3 setae. 
Mandible (Fig. 4D): Form unchanged; left mandible with 
four denticulate setae; right mandible with one denticu- 
late seta. 
Maxillule (Fig. 4E): Biramous; coxal endite with eight 
setae, basal endite with five stout setae and one seta; en- 
dopod three-segmented with 2, 2, 5 setae; exopod with four 
plumose setae. 
Maxilla (Fig. 4F): Biramous; endites with 10, 4, 4, 5, 3 
setae; endopod four-segmented with 3, 2, 2, 3 setae; exopod 
unchanged. 
First maxilliped (Fig. 40: Biramous; coxa with six se- 
tae, basis with 12 setae; endopod with 3, 2, 2, 4 setae; exo- 
pod unchanged. 
Second maxilliped (Fig. 4H): Biramous; coxa with one 
seta, basis with nine setae; endopod four-segmented with 
2, 2, 2, 5 setae; exopod with six plumose setae. 
Third maxilliped (Fig. 41): Undeveloped biramous; exo- 
pod with three plumose setae. 
Post-carapacial region (Fig. 4A): Six thoracic and six 
abdominal somites; unsegmented abdomen with forked 
telson. 
Telson (Fig. 4A): Unchanged. 
Third protozoeal stage (Fig. 5, A-K) 
Size TL: 2.22 mm ( 1.80-2.43 mm; SD=0. 18; 72 = 11 ) 
CL: 0.60 mm (0.50-0.70 mm; SD=0.06 : 77 = ] 1 ) 
Cephalothorax (Fig. 5A): Incompletely covered by cara- 
pace; carapace armed with long rostrum and two pairs of 
supraorbital spines; rostrum long. 
