FECUNDITY OF NORTHERN SHRIMP, PANDALUS BOREALIS, 



(CRUSTACEA, DECAPODA) IN AREAS OF 



THE NORTHWEST ATLANTIC 



D. G. Parsons and G. E. Tucker 1 



ABSTRACT 



Fecundity of the northern shrimp, Pandal-us borealis, and relationships between number of eggs and 

 carapace length were determined from 15 samples taken in 9 areas of the Northwest Atlantic. The sam- 

 pling area extended from Davis Strait to the south coast of Newfoundland. Comparisons of samples 

 suggested that fecundity levels can vary between seasons, years, and areas. A relationship between egg 

 production and environmental temperature was not evident from available samples. 



The northern or pink shrimp, Pandalus borealis, is 

 a protandric hermaphrodite with a circumboreal 

 distribution. In the Northwest Atlantic, it occurs 

 from about lat. 75 °N at West Greenland to about 

 lat. 42°N at Georges Bank (Squires 1970). Fecun- 

 dity of this species in the North Atlantic has been 

 studied in southern Norway (Rasmussen 1953), 

 northern Norway (Thomassen 1977), the North Sea 

 (Allen 1959), Iceland (Skuladottir et al. 1978), West 

 Greenland (Horsted and Smidt 1956), Barents Sea 

 (Teigsmark 1983), and Gulf of Maine (Haynes and 

 Wigley 1969). Bottom water temperatures recorded 

 at depths where shrimp samples were collected dur- 

 ing these studies varied considerably between areas 

 but were within the range of tolerance for survival 

 of adults as reported by Allen in 1959 (-1.68° to 

 11.13°C). 



This paper provides information on the fecundity 

 of P. borealis in the Northwest Atlantic. Samples 

 were collected in areas of known shrimp concentra- 

 tion off Baffin Island, in the eastern Hudson Strait 

 and Labrador Sea, and off the south coast of New- 

 foundland. Bottom temperatures at sampling sites 

 also varied between these areas but were confined 

 to the lower half of the tolerance range (<7°C). Com- 

 parisons are made between selected combinations 

 of the data sets presented. The possible effects of 

 ambient temperature on fecundity levels also are 

 considered. 



MATERIALS AND METHODS 



Samples of ovigerous female shrimp were col- 



lected opportunistically during various research 

 cruises conducted by or for the Department of 

 Fisheries and Oceans, St. John's, Newfoundland, 

 Canada, between 1971 and 1982. A total of 15 

 samples was selected for analysis. These were taken 

 from the Baffin Island area (east of Cumberland 

 Sound); Hudson Strait; North Labrador Sea; Hope- 

 dale, Cartwright, and Hawke Channels (on the 

 Labrador Shelf); St. Mary's Bay; Fortune Bay; and 

 the Southwest Newfoundland coast (Fig. 1). For 

 some areas, only one sample was available while for 

 others, samples were obtained in different months 

 and/or different years (Table 1). 



Only animals in good condition were selected from 

 the trawl catches for the study (i.e., no noticeable 

 damage and egg mass undisturbed). Individuals 

 were selected over the complete size range of 

 females, preserved in 10% Formalin 2 and returned 

 to the laboratory. It was assumed that within any 

 length group the selection (in terms of number of 

 eggs) was random. 



Oblique carapace lengths were measured to the 

 nearest 0.1 mm using Vernier calipers. This 

 measurement is the distance between the posterior 

 margin of the orbit of the eye and the posterodorsal 

 margin of the carapace (Rasmussen 1953). 



All eggs were removed from the pleopods, spread 

 in a Petrie dish, and oven dried overnight at 60°C. 

 After drying, eggs were further separated and 

 counted. 



Accuracy of the counts was determined by re- 

 counting the eggs from 49 animals. Differences from 

 the initial counts in 48 cases varied between - 5.75% 



'Fisheries Research Branch, Department of Fisheries and 

 Oceans, P.O. Box 5667, St. John's, Newfoundland A1C 5X1, 

 Canada. 



2 Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



Manuscript accepted December 1985. 

 FISHERY BULLETIN: VOL. 84, NO. 3, 1986. 



549 



