HAYNES: PANDALUS GONIURUS LARVAE 



bears six pairs of spines, the outermost (sixth) pair 

 usually without spinules. 



STAGE V ZOEA 



Total length of Stage V 10.3 mm (range 8.2-11.3 

 mm; 10 specimens). Rostrum (Figure 5A) with five 

 or six dorsal teeth and no ventral teeth; tip smooth 

 but may bear small hump indicating future loca- 

 tion of bifid tooth. Epipodite of second maxilliped 

 lobed. Mastigobranchiae occur as minute buds on 

 third maxilliped and pereopods 1-3. 



ANTENNULE.— Inner fiagellum usually four- 

 segmented; still bears terminal spine. Outer 

 fiagellum three-segmented; bears four groups of 

 three aesthetascs each in addition to terminal aes- 

 thetascs. 



ANTENNA (Figure 5B).— Fiagellum about 1.7 

 times length of scale; 11-12 segments. 



FIRST PEREOPOD (Figure 5C).— Propodite pro- 

 jects anteriorly but not as much as in second 

 pereopod; projection bears small spine terminally. 

 Neither dactylopodite nor propodite projection 

 bear subterminal spines. 



SECOND PEREOPOD (Figure 5D).— Chela well 

 formed. Dactylopodite bears two spines subtermi- 

 nally, and propodite projection one spine subter- 

 minally. Carpopodite not segmented. 



PLEOPODS (Figure 5E).— Segmented; length 

 about two-thirds height of second abdominal seg- 

 ment. Flagella tipped with several simple setae, 

 except first pair of pleopods bears setae only on 

 outer fiagellum. 



TELSON (Figure 5F). — Uropods similar in shape 

 to adult; telson margins somewhat parallel, bear 

 two spines each. Terminal margin straight or only 

 slightly emarginated, bears six pairs of spines. No 

 evidence of transverse hinge of exopodite of 

 uropod. 



STAGES VI AND VII (MEGALOPA 

 AND FIRST JUVENILE) 



Total length of Stage VI (megalopa) 13.8 mm 

 (11.1-15.8 mm; 6 specimens). Carapace without 



supraorbital spine. Rostrum (Figure 6A) shaped 

 as in adult; posterior dorsoventral width not as 

 pronounced nor ventral teeth as fully developed as 

 in Stage VII; bears eight or nine teeth dorsally in 

 addition to distinct bifid tip and four or five teeth 

 ventrally. Usually one or two setae occur between 

 several of the posterior dorsal teeth. Exopodites on 

 third maxilliped and pereopods reduced. Mas- 

 tigobranchiae larger but still not evident on fourth 

 pereopod. Pleurobranchiae clearly lobulated. 

 Inner fiagellum of antennule five- or six-seg- 

 mented and outer fiagellum four-segmented. 

 Inner fiagellum lacks terminal spine. Outer fiagel- 

 lum bears subterminally six groups of three aes- 

 thetascs each; terminal segment lengthened, 

 without aesthetascs. Mouthparts shaped as in 

 adult; mandibular palp present, two-segmented, 

 without setae. Chelae of first and second pereopods 

 shaped as in adult; carpal joints of left and right 

 second pereopods 20 to 25 and 7 to 9, respectively. 

 Meropodite of left second pereopod three- 

 segmented. Pleopodal setae extend along entire 

 lateral margins of both fiagella; tips of appendix 

 internae bear several distinct cincinnuli. Telson 

 (Figure 6B) shows, for first time, shape and spina- 

 tion similar to adult; lateral margins narrow pos- 

 teriorly but widen slightly at terminal margin. 

 Typically three pairs of spines on lateral margins 

 of telson but often a spine, rarely two, lacking. 

 Terminal margin of telson rounded but not as 

 much as in Stage VII; bears three pairs of stout 

 spines. Transverse hinge of uropod exopodite com- 

 plete. 



Total length of Stage VII (first juvenile) 14.9 

 mm (range 13.7-15.8 mm; 3 specimens). Rostrum 

 (Figure 7 A) typically adult; posterior dorsoventral 

 width slightly greater than in Stage VI; ventral 

 teeth fully formed and one or two setae between 

 most, if not all, teeth including bifid tip. No exopo- 

 dite on third maxilliped or pereopods. Mastigo- 

 branchia evident on fourth pereopod. Flagella of 

 antennules lengthened as in adult; outer fiagel- 

 lum nine-segmented, bears nine groups of three 

 aesthetascs each; inner fiagellum six-segmented. 

 Mandibular palp three-segmented, with spinous 

 setae. Carpal joints of left and right second 

 pereopods 29 and 11, respectively. Meropodite of 

 left second pereopod 1 1-segmented. Telson (Figure 

 7B) adult in shape, typically bears four pairs of 

 lateral spines although often lacks a single lateral 

 spine. 



245 



