46 s 



FIGURE 1. — Location of areas sampled for rock 

 crabs in the Bay of Fundy and southwestern 

 Nova Scotia. 



FISHERY BULLETIN: VOL. 81, NO. 2 

 64° 



New Brunswick 



Mc Null I. 



left chela (Fig. 2), width of the sixth abdominal seg- 

 ment (see figure 4 in Bigford 1979) to the nearest 0.1 

 mm, whole body wet weight to the nearest 0.0 1 g, sex, 

 and gonad stage (Table 1) for each crab. Eggs only 

 were removed from ovigerous females and preserved 

 in 5% Formalin 3 for 24 h then dried to a constant 

 weight at 70°C for 48 h. The total number of eggs was 

 calculated from the weight of the total egg mass 

 divided by the average weight of an egg estimated 

 from the known number (counted under dissecting 

 microscope) and weight of three subsamples of about 



'Reference to trade name does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



FIGURE 2.— Diagram of a male rock crab left chela indicating the 

 chela height (h) measurement taken; D = dactyl; P = propus. 



500-1,000 eggs. 



Gonad stages (Table 1) were based on a modified 

 version of Haefner (1976) who indicated six stages of 



Table 1.— Stages in gonad development of rock crab, Cancer irroratus (modified from Haefner 1976). 



Stage of 

 development 



Male 



Female 



1. Undeveloped 



2. Slight 



3 Moderate 



4. Developed 



5. Well developed 



Gonads not detectable without microscope. 



Vasa deferentia evident. Testes small or not 

 apparent. Colorless. 0-8 small, developing sper- 

 matophores per 0.1 mm 2 . 



Testes and vasa deferentia of approximately equal 

 weight orvasa deferentia slightly heavier. Gonads 

 quarter to half volume of hepatopancreas. 

 White. 8-35 well-developed spermatophores 

 per 0.1 mm 2 . 



Gonads half volume of hepatopancreas. Vasa 

 deferentia more than 3 times heavier than testes. 

 White. >30 well-developed spermatophores 

 per 0.1 mm 2 . 



Gonads dominant organ. White. >100 well- 

 developed spermatophores per 0.1 mm 2 . 



Ovaries threadlike. Colorless to white. No 

 oocytes. 



Ovary half volume of hepatopancreas. White to 

 light orange. Oocyte diameter 0. 1 -0.5 mm. 



Ovary volume approximately equal to that of 

 hepatopancreas. Light orange to orange. Oocyte 

 diameter 0.2-0.5 mm. 



Ovary larger than hepatopancreas. Orange to red. 

 Oocyte diameter 0.2-0.5 mm. 



358 



