COLVOCORESSES and MUSICK: CONTINENTAL SHELF DEMERSAL FISHES 



TABLE 3. — Major recurrent species groups, NMFS Groundfish Survey, 

 Mid-Atlantic Bight area, 1967-76. Faunal affinity is designated after 

 each species name: Boreal, Bo; warm temperate, WT; inner shelf resi- 

 dent, IS; outer shelf resident, OS; slope resident, SI. 



Spring cruises 



Fall cruises 



Gadus morhua Bo 

 Hemitripterus amencanus Bo 

 Pseudopleuronectes americanus Bo 



B 



Limanda ferrugmea Bo 

 Macrozoarces americanus Bo 

 Myoxocephalus octodecemspinosus Bo 

 Ra/a erinacea Bo 

 Scopthalmus aquosus IS 



Lophius americanus Bo 

 Merluccius bilineans Bo 

 Paralichthys oblongus OS 

 Squalus acanthias Bo 

 Urophycis chuss Bo 



Centropristes striata WT 

 Paralichthys dentatus WT 

 Pepnlus tnacanthus WT 

 Prionotus carolmus WT 

 Stenotomus chrysops WT 

 Urophycis regia WT 



Chloropthalmus agassizi SI 

 Helicolenus dactylopterus SI 

 Merluccius albidus SI 

 Urophycis tenuis Bo-SI 



Centropristes striata WT 

 Mustelus canis WT 

 Paralichthys dentatus WT 

 Prionotus carolinus WT 

 Stenotomus chrysops WT 



B 



Umanda ferrugmea Bo 

 Myoxocephalus octodecemspinosus Bo 

 Pseudopleuronectes americanus Bo 

 flaya erinacea Bo 

 Scophthalmus aquosus IS 

 Squalus acanthias Bo 



Cithanchthys arctifrons OS 

 Lepophidium cervmum OS 

 Merluccius bilinearis Bo 

 Paralichthys oblongus OS 

 Peprilus triacanthus WT 

 Urophycis chuss Bo 

 Urophycis regia WT 



Glyptocephalus cynoglossus Bo-SI 

 Lophius americanus Bo 

 Urophycis tenuis Bo-SI 



Chloropthalmus agassizi SI 

 Helicolenus dactylopterus SI 

 Merluccius albidus SI 



species, reflecting a very uniform distribution. 

 Limanda ferruginea was the only major species to 

 undergo a notable change in dominance, showing 

 a pronounced decline only during the last 2 yr of 

 the study. Parrack 4 has carefully linked the de- 

 cline of this valuable commercial species to 

 overfishing. 



Squalus acanthias and Peprilus triacanthus, 

 two of the most dominant species, showed strong 

 seasonal differences in the groups with which they 

 clustered. Squalus, a boreal cold-water species, 

 was widespread in the spring and occurred in the 

 ubiquitous group, but during the fall cruises this 

 species was restricted to the cooler waters on the 

 northern shelf and generally clustered with the 

 Limanda -dominated cold-water group. Peprilus 

 triacanthus generally appeared in the same group 

 as the other warm-temperate species in the spring 

 when it was distributed along the outer shelf, but 

 in the fall this species was widespread across the 



4 Parrack, M. L. 1973. Current status of the yellowtail 

 flounder fishery in ICNAF Subarea 5. Int. Comm. North w. Atl. 

 Fish., Res. Doc. 73 104, Ser. No. 3067, 3 p. 



shelf and tended to be more concentrated in the 

 cooler portions of the study area and usually clus- 

 tered with the semi-ubiquitous Merluccius 

 bilinearis-Urophycis chuss group. Peprilus 

 triacanthus is considerably more tolerant of cooler 

 temperatures than the other warm-temperate 

 species encountered in this study (Horn 1970). 

 Urophycis regia, another warm-temperate species 

 which inhabits cooler waters (Struhsaker 1969), 

 clustered similarly to Peprilus triacanthus, occur- 

 ring with the warm-temperate group in the spring 

 and with the semi-ubiquitous group in the fall; 

 however, it appeared to have slightly narrower 

 temperature tolerances, as it was more restricted 

 to the southern portion of the outer shelf in spring 

 and tended to be more concentrated in deeper, 

 warmer waters in the fall. 



Absolute abundances, both of total catches and 

 of individual species, varied to a much greater 

 extent than did the relative abundances between 

 species throughout the study. Because abundance 

 trends for the fall cruises have been well docu- 

 mented by Clark and Brown (1977) and the change 



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