Alaska to Puget Sound; it is also present in northern Europe 

 and in the Sea of Okhotsk and enjoys a widespread distribu- 

 tion throughout the Arctic, it is considered to be a circumpo- 

 lar species (Johnson 1934; Morris 1951, 1973; Ockelmann 

 1958; Tebble 1966; Abbott 1974; Emerson et al. 1976). 



Musculus niger is a common musculus represented in our 

 collection by 406 specimens from 115 samples (Table 5). 



The samples in the NEFC collection occur from Nova 

 Scotia to slightly south of Delaware Bay, on the continental 

 shelf, and around the periphery of the Gulf of Maine and on 

 Georges Bank (Fig. 66, Theroux and Wigley footnote 4, table 

 114). 



The main distribution for this species is panarctic and 

 Boreal (Ockelmann 1958); Coomans (1962) placed it in the 

 Arctic, Boreal, Virginian, and Celtic provinces; Gosner's 

 (1971) view was that it is Boreal and Virginian, while Dance 

 (1974) placed it in the Arctic, the Boreal, Transatlantic, and 

 Aleutian zoogeographic provinces. 



The bathymetric range of this species extends from 2 to 1 10 

 m (Gosner 1971; Abbott 1974). 



Our suite of samples ranges in depth between 15 and 264 m 

 with a mean of 76 m. The majority of the samples (55%) and 

 specimens (58%) are in the 50-99 m depth range grouping; the 

 100-199 m grouping contains 22% of the samples and 16% of 

 the specimens: the 25-49 m grouping, 20% of the samples and 

 24% of the specimens; 3% of the samples and 1% of the 

 specimens are in the 0-24 m depth range grouping and < 1 % of 

 both samples and specimens in the 200-499 m grouping (Table 

 102). 



This species can be found in rock crevices and it is also 

 found attached to empty shells (Morris 1973). 



Our samples occupied all the sediment types considered in 

 this report. The preferred sediment type, at least with regard 

 to amounts of samples and specimens, was sand which con- 

 tained 40% of the samples and 25% of the specimens; sand- 

 gravel substrates were next with 15% of the samples and 20% 

 of the specimens while till contained 7% of the samples but 

 25% of the specimens. Smaller amounts were recorded from 

 gravel, shell, sand-shell, silty sand, silt, and clay substrates 

 (Table 103). There are 10 samples containing 34 specimens 

 which are unclassified with regard to sediment type. 



Musculus sp. Figure 67. 



The NEFC specimen reference collection contains 13 sam- 

 ples which yielded 75 specimens of this genus (Table 5). 



Samples containing specimens of Musculus are from the 

 Gulf of Maine and the northern edge of Georges Bank (Fig. 67; 

 Theroux and Wigley footnote 4, table 115). 



The depth range of the NEFC samples is from 35 to 256 m 

 with a mean of 1 15 m. The majority of the samples (54%) are in 

 the 50-99 m grouping, but the majority of specimens (57%) are 

 in the 100-199 m grouping, the former contained 23% of the 

 specimens and the latter 15% of the samples; 23% of the 

 samples and 9% of the specimens are in the 200-499 m group- 

 ing and 8% of the samples and 11% of the specimens in the 

 25-49 m depth range grouping (Table 104). 



There was not a great deal of variability in the abundance of 

 samples occurring in the various sediment types in which they 

 were found, but more discrepancy in the amounts of speci- 

 mens obtained from each sediment type. Sand-gravel con- 

 tained 30% of the samples, while gravel and clay each con- 



tained 20% of the samples; till, sand, and silty sand each 

 contained 10% of the samples. In terms of numbers of organ- 

 isms the majority of specimens (61%) were obtained from 

 gravel substrates; there was 27% in sand-gravel substrates, 

 5.6% in clay, 4% in till, and 1.4% each in sand and silty sand 

 (Table 105). There are three samples containing four speci- 

 mens which are unclassified with regard to sediment type. 



Genus Mytilus Linne 1758 

 Mytilus edulis Linne 1758. Blue mussel. Figure 70. 



The blue mussel enjoys a widespread distribution through- 

 out northern oceans occurring in both the North Atlantic and 

 North Pacific Oceans. In the Atlantic it occurs from the Arctic 

 Ocean to South Carolina while in the Pacific it ranges from 

 Alaska to California and is also found in Japan; in Europe it 

 ranges along the European coast into the Mediterranean and 

 Baltic Seas (Johnson 1934; LaRocque 1953; Ockelmann 1958; 

 Tebble 1966; Abbott 1968, 1974; Morris 1973; Emerson et al. 

 1976). Porter (1974) stated that below Cape Hatteras, N.C., 

 specimens are usually small or young. 



Mytilus edulis, which is very common in New England and 

 common elsewhere throughout its range, is well represented 

 in the NEFC collection which contains 5,272 specimens 

 which make up 5% of the total number of specimens from 107 

 samples or 1% of the total number of samples (Table 5). 



Our samples range from the Scotian Shelf into the Gulf of 

 Maine, on Georges Bank, in the Cape Cod region, south to 

 inshore waters off New York City; they occur in the mouth of 

 Delaware Bay, in Chesapeake Bay, and Pamlico Sound; there 

 is one offshore sample off Charleston, S.C. (Fig. 70; Theroux 

 and Wigley footnote 4, table 120). 



The main distribution, according to Ockelmann (1958), is 

 low Arctic-boreal and discontinuously circumpolar; it is also 

 Mediterranean- Atlantic. Coomans (1962) placed it in the Arc- 

 tic-boreal, Virginian, and Celtic provinces, while Gosner 

 (1971) placed it in the Boreal and Virginian provinces; Dance 

 (1974) considered it to occupy the Boreal, Mediterranean, 

 Atlantic, Aleutian, Caribbean, and Transatlantic provinces 

 and mentioned that it was introduced into the Japonic and the 

 Indo-Pacific provinces. 



Ockelmann (1958) listed the depth range for this species as 

 occurring between the tidal zone to 180 m at Jan Mayen and 

 mentioned that it is only occasionally found at depths below 

 50 m; Gosner (1971) and Morris (1973) reported it from the 

 littoral region intertidally to shallow water. 



The NEFC samples range in depth from to 232 m with a 

 mean of 52 m. In order of decreasing depth range. 34% of the 

 samples and 15% of the specimens are in the 0-24 m grouping, 

 22% of the samples and 73% of the specimens in the 25-49 m 

 grouping, 33% of the samples and 12% of the specimens in the 

 50-99 m grouping with a sharp dropoff in abundance occurring 

 at the 100-199 m grouping which contains 9% of the samples 

 and 0.5% of the specimens, while 3% of the samples and 0. 1% 

 of the specimens are in the 200-499 m grouping (Table 106). 

 There is one sample which contains three specimens which 

 has no associated depth information. 



The only sediment type, of the nine considered in this 

 report, which did not contain specimens of Mytilus edulis was 

 sand-shell. Abundance in terms of decreasing particle size 

 was as follows: 7% of the samples and 3% of the specimens 



19 



