HAYNES DESCRIPTION OF PA.VD.AZ.C.S BOREALIS LARVAE 



flagellai. — Flagella two-segmented. Inner flagel- 

 lum nearly as long as outer flagellum. Outer 

 flagellum bears four aesthetascs and two spines 

 terminally and three groups of three aesthetascs 

 each on proximal segment. 



ANTENNA (Figure 4C ). — Flagellum 15- 

 segmented; 1.5-2 times length of scale, extending 

 past tips of plumose setae fringing antennal scale. 

 Antennal scale without joints at tip. Other than 

 increase in size, changes in antennal scale from 

 Stage IV onward are negligible. 



FIRST PEREOPOD (Figure 4D).— Distal joint 

 of propodite projected anteriorly and tipped with 

 small spine. 



SECOND PEREOPOD (Figure 4E).— Distal 

 joint of propodite projected anteriorly to about 

 one-half length of dactylopodite; projection tipped 

 by two spines, one terminal and other subterminal 

 and much shorter. Dactylopodite bears one termi- 

 nal spine and two considerably shorter subtermi- 

 nal spines. 



PLEOPODS (Figure 4F, second pleopod).— 

 Segmented; length of second pair of pleopods about 

 one-half height of second abdominal somite. 

 Exopodite usually bears one to four small setae 

 terminally and endopodite sometimes bears single 

 seta terminally. Appendices internae not present. 



TELSON (Figure 4Gi.— Endopodite of uropod 

 about two-thirds length of exopodite and fringed 

 with about 20 setae. Lateral margins of telson 

 nearly parallel but slightly divergent posteriorly 

 and bear two spines each. Posterior margin still 

 slightly emarginate; bears 6 -(- 6 spines, the out- 

 ermost (sixth) pair usually without spinules. 



STAGE V ZOEA 



Mean total length of Stage V 16.0 mm (range 

 15.2-17.1 mm; 10 specimens). Rostrum (Figure 

 5A) with 9-12 dorsal teeth, bifid tip, and usually 4. 

 but sometimes 5, partially developed ventral teeth. 

 Pleurobranchiae curve somewhat anteriorly and 

 edges minutely lobulate. Mastigobranchiae occur 

 as minute buds on protopodite of third maxilliped 

 and pereopods 1-4. 



ANTENNULE (Figure 5B, flagella only).— 

 Inner flagellum four-segmented. Outer flagellum 



four- or five-segmented; bears six groups of three 

 aesthetascs each. Each segment bears at least one 

 seta but number and location of setae somewhat 

 variable. 



ANTENNA (Figure 5C).— Flagellum 2-3 times 

 length of scale. 



FIRST PEREOPOD (Figure 5D, distal segments 

 only). — Projection of propodite at least one-half 

 length of dactylopodite; bears two small spines, 

 one terminally and one subterminally. Dactylopo- 

 dite bears small spine subterminally in addition to 

 terminal spine. 



SECOND PEREOPOD (Figure 5E, distal seg- 

 ments onlyl. — Chela well formed. Terminal spine 

 of propodite shorter and stouter than in Stage IV. 

 Dactylopodite bears five spines, the distal two 

 especially stout. Carpopodite usually at least par- 

 tially segmented. 



PLEOPODS (Figure 5F, second pleopod).— 

 Second pair of pleopods about equal in length to 

 height of second abdominal somite; outer flagel- 

 lum fringed with 11 or 12 plumose setae, inner 

 flagellum with about 8 setae. Appendices internae 

 usually present on pleopods 2-5; tips sometimes 

 bear a few cincinnuli. 



TELSON (Figure 5G). — Lateral margins of tel- 

 son essentially parallel and bear two spines each. 

 Posterior margin straight or slightly emarginate, 

 bearing 6 + 6 spines. Uropods similar in shape to 

 adult; no evidence of transverse hinge of exopo- 

 dite. 



STAGE VI (MEGALOPA) 



Mean total length of Stage VI 18.5 mm (range 

 17.4-20.2 mm, 5 specimens). Rostrum (Figure 6A) 

 shaped as in adult; bears 13-15 dorsal teeth in 

 addition to distinct bifid tip, and 6 or 7 distinct 

 ventral teeth. Usually one or two setae between 

 dorsal teeth. Carapace lacks supraorbital spine. 

 Exopodites on maxillipeds and pereopods 1-3 re- 

 duced. Pleurobranchiae and mastigobranchiae 

 shaped as in adult. Inner and outer flagella of 

 antennule eight- to nine-segmented and five- 

 segmented, respectively. Flagellum of antenna 

 about 6 times length of antennal scale. Mandibles 

 still without palps. Chaelae of first and second 

 pereopods shaped as in adult; carpal joints of left 



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