IIAYNKS: I'ANDAl.lDAK. llll'l'(>l,> TIDAK. AM i CKANCONMDAK I.AKVAK 



Lateral niarjiins of telsoii parallel (ir narrow 

 posteriorly 6 



6. Rostrum with 5 developed dorsal teeth and 1 

 un(ieveloped dorsal tooth; antennal flaj^ellum 

 with If) segments and same lenjj;th as scale 



Stage VI 



Rostrum with ^ 5 developed dorsal teeth and 



> 1 undeveloped dorsal tooth; antennal tla- 

 gellum with > 20 segments and longer than 

 scale 7 



7. Rostrum with 5 developed dorsal teeth and 



styliform tip; anal spine absent Stage VII 



Rostnmi with > 5 developed teeth, tip of 

 rostrum with precursor of sub terminal tooth; 

 anal spine present 8 



8. Rostrum with 7 developed teeth; lateral 



margin of telson with 2 spines Stage VIII 



Rostrum with > 7 developed teeth; lateral 

 margin of telson with ^ 3 spines 9 



9. Rostrum with 9 developed teeth; inner flagel- 

 lum of antennule with 3 segments; outer 

 flagellum of antennule with 2 segments 



Stage IX 



Rostnun with > 9 developed teeth; inner 

 flagellum of antennules with ^ 4 segments; 

 outer flagellum of antennule with 3 segments 



10 



10. Rostrum with 10 developed teeth; medial 

 pair of terminal telsonic spines shorter than 



adjacent pair Stage X 



Rostrum with > 10 developed teeth; medial 

 pair of terminal telsonic spines same length 



or longer than adjacent pair 11 



11. Inner flagellum of antennule with 4 seg- 

 ments; medial pair of terminal telsonic spines 



same length as adjacent pair Stage XI 



Inner flagellum of antennule with 5 seg- 

 ments; medial pair of terminal telsonic spines 

 longer than adjacent pair 12 



12. Rostrum with 12 developed dorsal teeth and 

 precursors of 3 ventral spines; terminal 



margin of telson straight Stage XII 



Rostrum with > 12 developed dorsal teeth 

 and precursors of > 3 ventral teeth; terminal 

 margin of telson convex 13 



13. Carapace with supraorbital spine; pereopod 2 



with unsegmented car|)us Stage XIII 



(last larval stage) 

 Carapace without supraorbital spine; pereo- 

 pod 2 with segmented carpus Stage XIV 



(first juvenile stage) 



Pandalus kessleri Czerniavski 



Voxxv larval stages. 



Stages I-IV and Stage V (first juvenile), known 

 parentage; figures 2-6 (fig. 6, first juvenile stage) 

 in Kurata(1955). (Stages II-IV have a mixture of 

 zoeal and megalopal characters.) 



Abbreviated larval development. In all described 

 stages, carapace without denticles along antero- 

 ventral margin; antennal scale not jointed at tip; 2 

 lateral setae proximally on exopodite of maxilliped 1 . 

 Stages II and III with transverse dorsal groove. 

 Rostrum with teeth beginning in Stage II. Supra- 

 orbital spines in Stage II only. In Stage I, antennal 

 flagellum 3/4 length of body; antennal flagellum 

 segmented throughout its length; telson with 30-34 

 setae; anal spine present; zoea longer than 8.1 mm. 

 In Stage III, mandible with unjointed palp. Vestigial 

 exopodites on pereopods 1 and 2 in Stages I and II. 

 Pleopods with plumose setae in Stage II. Length: 

 Stages I-IV, 8.1-10.8 mm. Range: Hokkaido, Japan 

 (no depth given) (Kurata 1955). 



Key VIII. — Larval and first juvenile stages of Pandalus 



kessleri. 



1. Rostrum without teeth; eyes sessile .... Stage I 

 Rostrum with teeth, eyes stalked 2 



2. Mandible without palp; uropods enclosed; 



carapace with supraorbital spine Stage II 



Mandible with palp; uropods free; carapace 

 without supraorbital spine 3 



3. Rostral tip not bifid; telson widens posteri- 

 orly Stage III 



Rostral tip bifid; telson margins parallel or 

 narrows posteriorly 4 



4. Mandibular palp unsegmented; sides of 

 telson parallel; telson with 2 pairs of lateral 



spines and 11-14 terminal seta Stage IV 



Mandibular palp segmented; telson narrows 

 posteriorly; telson with 3 pairs of lateral 

 spines and several terminal setae vestigial as 

 hairs Stage V 



(first juvenile) 



271 



