130 



NOAA Technical Report NMFS 140 



320 



I — I NUMBER 

 ■i WEIGHT 



S 240 

 O 



- 



en O 



z m 



o 5 



cr UJ 



lj or 



CD < 



2 => 



3 O 

 2 V) 



(JO 





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00 ^ u. 

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 uj O 



or 



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GRAVEL TILL SHELL SAND SAND- SILT- 



SILT CLAY 



BOTTOM SEDIMENTS 



Figure 120 

 Densitv and biomass of Bivalvia in relation to bottom sediments. 



and relatively uniform, ranging from 80 to 100% 

 between the 0.00 and the 2.00-2.99% classes; the 

 lowest occurrence (75%) was in the 3.00-4.99% class 

 (Table 30). 



Scaphopoda — Scaphopods constituted a minor compo- 

 nent of the New England benthic fauna. They accounted 

 for 0.2% of the number of animals and 0.3% of biomass 

 in the total benthic fauna (Table 3). These samples 

 included the first representative of the genus Cadulus 

 known to occur in the Gulf of Maine (Wigley, 1966b). 

 This same report postulated that the relativel) warm 

 high-salinity bottom water in the larger Gulf of Maine 

 basins permitted scaphopods from the continental slope 

 to inhabit deeper sections of the Gulf. 



They are burrowing forms that most commonly in- 

 habit medium to fine-grained sediments. The head and 

 relatively large foot project from the anterior (larger) 

 aperture of the shell. When buried in the sediment the 

 anterior end of the shell faces downward and the poste- 

 rior end is pointed upward. Scaphopods have plank- 

 tonic eggs and free-swimming trochophoric larvae. 



This group of mollusks is taxonomically small. Less 

 than a score of species and one-half dozen genera are 

 known from the New England region. Sizes of speci- 

 mens in our samples ranged from about 1 to 6 cm in 

 length. 



Color of the shells was generally various shades of 

 white, either uniformly white, or white with partial dis- 

 colorations of yellow or brown, or occasionally black. 



