MIDDLETON and MUSICK: ABUNDANCE AND DISTRIBUTION OF MACROURIDAE 



folk Canyon area was 46 cm, exactly that which was 

 found for C. rupestris in the Newfoundland bank 

 area. However, no small C. rupestris were captured 

 in the Norfolk Canyon area. We found only 2 fish 

 with a head length <40 mm (24 cm TL) and only 10 

 fish with head length <50 mm (30 cm TL). 



The regression line for head length against log 

 (weight) (Fig. 2) was analyzed. The solution for C. 

 rupestris males was log (weight) = 0.023 (head 

 length) + 0.82, r 2 = 0.898, and for females it was 

 log (weight) = 0.018 (head length) + 1.16, r 2 = 

 0.885. 



Unfortunately these length-weight data cannot be 

 compared directly with those summarized by Gor- 

 don (1979) because we measured head lengths in our 

 study and he gave standard lengths. We do not have 

 the data at present to compute the regression for 

 head length on standard length for this species. 



Temperatures at which C. rupestris were captured 

 near Norfolk Canyon ranged from 3.7° to 5.7°C 

 (Fig. 6). The average temperature was 4.9°C. 



Coryphaenoides rupestris does not follow the 

 "larger-fewer-deeper" pattern shown for N. bair- 

 dii in Norfolk Canyon because it migrates seasonally 

 (Fig. 16) and the larger specimens traverse the en- 

 tire bathymetric range (Fig. 13). 



In summary, C. rupestris migrated seasonally to 

 shallower water in the fall and early winter. Catch 

 per unit effort increased in the fall and winter, and 

 a dense aggregation was found in the fall. Podra- 

 zhanskaya's (1971) spawning and migration theory 

 appears feasible but further intensive study is need- 

 ed. No ripe, running, or spent fish were captured 

 in the Norfolk Canyon area out of 7,011 individuals 

 examined. There was a trend for the larger C. 

 rupestris to range deeper but not to the degree that 

 was found in N. bairdii. It appears that the distribu- 

 tion of C. rupestris was more closely related to 

 temperature than to depth, the species being found 

 mostly within the 4°-5°C range. 



Coryphaenoides carapinus (Goode and Bean 1883) 



Coryphaenoides carapinus is another small 

 macrourid which grows to about 390 mm TL, and 

 is found on the lower slope and abyss from 1,000 to 

 3,000 m (Haedrich and Polloni 1976). In the western 

 North Atlantic it has been found between Nova 

 Scotia and Cape Hatteras (lat 37°N) and in the 

 eastern Atlantic from lat. 50°N to the Equator. Cory- 

 phaenoides carapinus has also been reported 

 from the mid-Atlantic ridge (Marshall and Iwamoto 

 1973). 



In the Norfolk Canyon area C. carapinus was cap- 



tured at 1,108-2,767 m (Fig. 3). The largest number 

 caught in one trawl was 37 (total weight 550 g). 

 These were captured in September 1975 at a depth 

 of 1,803 m. Coryphaenoides carapinus comprised up 

 to 23.4% of a catch in number, but only 4.3% in 

 biomass. The maximum size captured was 90 mm 

 HL. 



Coryphaenoides carapinus tended to be larger at 

 the lower end of its depth range (Fig. 17). The slope 

 of the regression line for head length with depth was 

 significantly different than zero. The coefficient of 

 determination was 0.346. 



Figure 18 displays low numbers and high vari- 

 ability in the capture of C. carapinus in relation to 

 depth. The phenomenon of fewer, larger fish at the 

 deeper part of the bathymetric range was evident 

 but obscured because of the relatively small size of 

 C. carapinus, low numbers, and contagious 

 distribution. 



Coryphaenoides carapinus was taken at temper- 

 atures of 2.5°-4.2°C with the average temperature 

 being 3.7°C (Fig. 6). Some overlap in distribution 

 with depth and temperature occurred among C. 

 carapinus, C. armatus, and C rupestris. Because 

 C carapinus is a small species and mostly a ben- 

 thic feeder (Haedrich and Polloni 1976) and C. ar- 

 matus and C. rupestris are large species that forage 

 into the water column (Podrazhanskaya 1971; 

 Haedrich and Henderson 1974; Smith et al. 1979), 

 competitive interaction is probably low. 



Coryphaenoides armatus (Hector 1875) 



Coryphaenoides armatus is cosmopolitan in distri- 

 bution, being found in all oceans except the Arctic. 

 It commonly is found from 2,200 to 4,700 m, with 

 a few specimens being captured as shallow as 282 

 m (Marshall and Iwamoto 1973). Larger individuals 

 have been shown to forage off the bottom for pelagic 

 prey (Haedrich and Henderson 1974; Pearcy 1975; 

 Smith et al. 1979). Coryphaenoides armatus attains 

 a size of 165 mm HL and over 870 mm TL (Iwamoto 

 and Stein 1974). The largest specimen captured in 

 Norfolk Canyon was 146 mm HL. Although C. ar- 

 matus is one of the deepest living macrourids, it is 

 rather well-known biologically because of its broad 

 distribution and availability to deepwater trawls 

 (Haedrich and Henderson 1974; Pearcy and Ambler 

 1974; McLellan 1977; Smith 1978). 



Coryphaenoides armatus was taken in every suc- 

 cessful trawl from 2,100 m to our deepest trawl of 

 3,083 m in the Norfolk Canyon area and virtually 

 was confined to below the 3°C isotherm (Fig. 3). In 



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