DESCRIPTION OF ZOEAE OF COONSTRIPE SHRIMP, 

 PANDALUS HYPSINOTUS, REARED IN THE LABORATORY 



Evan Haynes^ 



ABSTRACT 



Zoeae oiPandalus hypsinotus from ovigerous females caught in Kachemak Bay, Alaska, were reared 

 in the laboratory. Each of the six zoeal stages is described and illustrated, and a brief description is 

 given for postzoeal Stages VII-IX. The descriptions are compared with descriptions of zoeal stages of P. 

 hypsinotus given by other authors. 



Although pandahd shrimp form a major fishery 

 resource along the Pacific coast of North America, 

 little has been published on their early life his- 

 tory, especially on identification of the larval 

 stages. Berkeley (1930) described the zoeal stages 

 of five pandalid species from British Columbia, 

 Pandalus borealis Kr0yer, P. danae Stimpson, 

 P. hypsinotus Brandt, P. platyceros Brandt, and 

 Pandalopsis dispar Rathbun. The first zoeal stage 

 of each species was obtained in the laboratory, and 

 various remaining stages were obtained from the 

 plankton. Berkeley also mentioned briefly the 

 growth and distribution of the zoeae. Of 14 species 

 of pandalid shrimps known to occur along the Pa- 

 cific coast of North America, only two species, 

 Pandalus jordani Rathbun and P. platyceros, have 

 been reared through all their zoeal stages in 

 the laboratory (Modin and Cox 1967; Price and 

 Chew 1972). 



In 1972, the National Marine Fisheries Service 

 began an intensive investigation at its field sta- 

 tion at Kasitsna Bay, Alaska, on the early life 

 history of pandalid shrimp in Alaskan waters. 

 The initial objective of the investigation was to 

 describe in detail laboratory-reared zoeae of each 

 pandalid species previously unverified. This re- 

 port describes and illustrates each of the six zoeal 

 stages of coonstripe shrimp, P. hypsinotus, and 

 compares the stages obtained from laboratory- 

 reared zoeae with stages obtained from the plank- 

 ton by other authors. Brief descriptions of post- 

 zoeal Stages VII through IX are also included. 



'Northwest Fisheries Center Auke Bay Fisheries Laboratory, 

 National Marine Fisheries Service, NOAA, P.O. Box 155, Auke 

 Bay AK 99821. 



MATERIALS AND METHODS 



Owigeroxxs Pandalus hypsinotus were caught at 

 depths of 54 m (30 fathoms) in shrimp pots in late 

 April 1973. They were kept in plastic buckets 

 filled with seawater for about V2 h and then were 

 put in plastic glass hatching boxes similar to those 

 used by Price and Chew (1972) for rearing zoeae of 

 spot shrimp, P. platyceros. The hatching boxes 

 were kept in a biologically filtered recirculating 

 aquarium system containing 190 liters (50 gallons) 

 of refrigerated seawater, of which 19 liters (5 

 gallons) were exchanged for fresh seawater every 

 other day. Salinity was maintained between 32 

 and 34'Z, and temperature between 6° and 8°C. 

 The quality and quantity of light were not 

 controlled, but direct sunlight was avoided. Most 

 zoeae were released at night but some were 

 released during daytime whenever a female 

 shrimp was stimulated to flex her abdomen 

 rapidly. No predation of zoeae by female shrimp or 

 by the zoeae themselves was noted. No prezoeae 

 were seen. 



About 50 zoeae were transferred by large-bore 

 pipette to each of 25 500-ml beakers containing 

 about 400 ml of aquarium seawater. In addition, a 

 zoea was placed in each of 50 25- by 50-mm num- 

 bered plastic vials held in compartmented trays. 

 The zoeae in the beakers provided both individual 

 specimens and cast skins of various stages for dis- 

 section, and the individual zoeae in the vials pro- 

 vided a continuous sequence of cast skins with a 

 known history. The beakers and vials were both 

 checked daily for exuviae. Seawater in the hold- 

 ing containers was changed every other day and 

 the zoeae were fed newly hatched nauplii of brine 

 shrimp, Artemf a salina, from San Francisco Bay. 



Manuscript accepted December 1975. 

 FISHERY BULLETIN: VOL. 74. NO. 2, 1976. 



323 



