FISHERY BULLETIN: VOL. 71, NO. 1 



Average density at seven stations was 33/m-, 

 and maximum density was 110/m-. 



Relations with Sediments 



The kinds of cephalopods that are abundant 

 in this region are pelagic and their occurrence 

 would not ordinarily be expected to be directly 

 related to substrate composition. The fate of 

 the remains of these animals that drop to the 

 ocean floor may depend indirectly on sediment 

 type because these species generally occur in 

 deep or moderately deep water. Cephalopod re- 

 mains were absent in coarse sand or gravel. 

 Densities were moderate (10 to 40/m^) exclu- 

 sively in silt. 



Caduhis and Dentalium remains also were 

 found only in fine-grained sediments; fine sand, 

 silty sand, sandy silt, and silt. No areas of 

 coarse sand, gravel, or mixtures of the two yield- 

 ed scaphopod shells. A large majority were in 

 areas where the sediments are fine sand and silty 

 sand. Cadulus was densest in fine sand, and 

 Dentalium in silty sand. 



REMAINS OF FISH 



Vertebrate remains in the bottom sediments 

 were represented exclusively by fish otoliths and 

 small numbers of bones, teeth, and scales (Table 

 14). Some examples of typical otoliths are il- 

 lustrated in Figure 18. Otoliths were rather 

 broadly distributed over much of the area but 

 were particularly common in the deepwater sec- 

 tion. The otolith density was strikingly high, 

 3,020/m-, near the shelf break south of Nan- 

 tucket Shoals. All samples combined included 

 18 genera and at least 26 species of fish ; all but 

 one were identified from otoliths. A record of 

 the otoliths of each species recovered at diff^erent 

 stations is given in Table 15. Eleven of the spe- 

 cies are bottom-dwelling types, and 11 are epi- 

 pelagic or mesopelagic (Table 16). Three spe- 

 cies, Merluccius albidus, M. bilinearis, and Pe- 

 prilus triacanthus, represented by otoliths range 

 widely from the sea bottom to upper water lev- 



els; they remain unclassified for the purposes 

 of this discussion. Clupeoids, scombroids, and 

 other common pelagic groups were lacking. The 

 collections included many more otoliths from pe- 

 lagic species (1,288), however, than from 

 groundfish (141); the average otolith density 

 (based only on samples containing one or more 

 otoliths), of pelagic species was 379/m^ com- 

 pared with 41/m2 for groundfish. All fish re- 

 mains were less than 2 cm in greatest dimension, 

 and most were less than 3 mm. The sizes of 

 fish from which these remains came ranged from 

 lanternfish only a few centimeters long to sharks 

 estimated to be 2 to 3 m long. 



' Scales occurred only at stations 11, 17, and 40 (10 to 20/m2) and 

 teeth only at stations 53 and 54 {20 to 30/m2). 



26 



