THE ABUNDANCE AND DISTRIBUTION OF 



THE FAMILY MACROURIDAE (PISCES: GADIFORMES) 



IN THE NORFOLK CANYON AREA 1 



Robert W. Middleton 2 and John A. Musick 3 



ABSTRACT 



The Norfolk Canyon off Virginia and the adjacent slope areas were sampled with 13.7 m otter trawls 

 in June 1973, November 1974, September 1975, and January 1976. Trawl depths ranged from 75 to 3,083 

 m, and 22 species of macrourids were captured during the study. Coryphaenoides rupestris demonstrated 

 seasonal movement to shallower water (ca. 750 m) during winter. Nezumia bairdii, N. aequalis, and Cory- 

 phaenoides carapinus exhibited a significant positive correlation between head length and depth (r 2 = 

 0.47, 0.37, and 0.35, respectively). Nezumia bairdii apparently spawns in July or August, and reaches 

 an age of about 11 years. New size records were established for Nezumia aequalis (64 mm head length 

 (HL)) and N. bairdii (66 mm HL). New depth records were established for Coelorinchus c. carminatus 

 and N. aequalis (884 and 1,109 m, respectively). The known geographic ranges for Coelorinchus carib- 

 beus, C. occa, Nezumia cyrano, Coryphaenoides colon, Hymenocephalus gracilis, H. italicus, Bathygadus 

 macrops, Macrourus berglax, and Gadomus dispar were extended to the Norfolk Canyon area. 



The Macrouridae (Pisces: Gadiformes) includes some 

 of the most abundant archibenthic deep-sea fish 

 species (Marshall 1965, 1971; Marshall and Iwamoto 

 1973; Iwamoto and Stein 1974) and attains greatest 

 abundance and diversity on the continental slopes 

 of the world oceans (Marshall and Iwamoto 1973). 

 Present knowledge of the life history and ecology 

 of macrourids has been accrued piecemeal from 

 faunal lists and taxonomic works (Gunnerus 1765; 

 Gunther 1887; Gilbert and Hubbs 1920; Farron 1924; 

 Iwamoto 1970; Okamura 1970; Marshall and 

 Iwamoto 1973; Iwamoto and Stein 1974), or from 

 studies on physiology, anatomy, and life history 

 (Kulikova 1957; Marshall 1965; Phleger 1971; Ran- 

 nou 1975; Rannou and Thiriot-Quiereaux 1975; 

 Haedrich and Polloni 1976; McLellan 1977; Merrett 

 1978; Smith et al. 1979). The meager literature on 

 reproduction and growth of macrourids and other 

 deep-sea anacanthine fishes has recently been 

 reviewed by Gordon (1979). With the advent of in- 

 creasing expertise in deepwater trawling, some 

 macrourid species, such as Coryphaenoides rwpestris 

 and Macrourus berglax, have become commercially 



•Contribution No. 1226 from the Virginia Institute of Marine 

 Science. 



2 Virginia Institute of Marine Science, College of William and 

 Mary, Gloucester Point, VA 23062; present address: Minerals 

 Management Service, U.S. Department of the Interior, 1951 Kidwell 

 Drive, Vienna, VA 22180. 



3 Virginia Institute of Marine Science, College of William and 

 Mary, Gloucester Point, VA 23062 



important in the western North Atlantic. Experi- 

 mental commercial trawling was initiated by the 

 Soviet Union in 1962, and many studies directly 

 related to the commercial fishing of macrourids have 

 been subsequently published by Soviet workers 

 (Podrazhanskaya 1967, 1971; Sawatimskii 1971, 

 1972; Grigor'ev 1972) and to a lesser extent by Polish 

 researchers (Stanek 1971; Nodzinski and Zukowski 

 1971). 



The present study examines the seasonal distribu- 

 tion and abundance of the macrourid species cap- 

 tured in the Norfolk Canyon area. In addition aspects 

 of age, growth, and reproduction of selected domi- 

 nant species are also described. 



MATERIALS AND METHODS 



Gear 



The data presented in this paper were obtained 

 on four cruises to Norfolk Canyon and the adjacent 

 open slope to the south (Fig. 1) conducted by the RV 

 Columbus Iselin (June 1973) and RV James M. Gillis 

 (November 1974, September 1975, January 1976). 

 On all cruises a 13.7 m semiballoon otter trawl with 

 1.3 cm (stretched) mesh in the cod end liner and 5.1 

 cm (stretched) mesh in the wings and body was 

 employed. Steel "china V" doors at the end of 22.9 

 m bridles were used to permit spreading of the net 

 from a single warp (Musick et al. 1975). 



Manuscript accepted March 1985. 



FISHERY RIILLETIN: VOL. 84. No. 1. 1986. 



35 



