162 



NOAA Technical Report NMFS 140 



Relation to Sediment Organic Carbon 



Tanaidaceans occurred only in areas of low organic 

 carbon (Tables 26, 28, 30; Fig. 165). Density, biomass, 

 and incidence of occurrence were all low in two organic 

 carbon content classes (0.01-0.49 and 0.50-0.99%). 



Isopoda — Isopods were moderately sparse but widely 

 distributed throughout New England waters. Because 

 of their limited abundance and small size they made up 

 only a small portion of the total benthic fauna. They 

 accounted for <1% of the total number of benthic 

 animals and only 0.2% of the total biomass (Table 3). 



Isopods in our samples ranged from 3 to 20 mm in 

 length; the majority of specimens were approximately 

 10 to 15 mm long. Color of most specimens was translu- 

 < cm to light tan or medium brown. 



Approximately 13 species of isopods were represented 

 in the collections, most of which belonged to the fami- 



lies Cirolanidae and Idoteidae. A new species, Chiridotea 

 arenicolaWigley ( 1960a), was described from specimens 

 found in collections from Georges Bank. 



A large proportion of the specimens were adapted 

 for burrowing in sand or for crawling on sandy or rocky 

 substrates. 



Isopods occurred in 390 samples (36% of total). Their 

 density averaged 12.1/m and their biomass averaged 

 0.29 g/m- (Table 5). 



Geograph ic I) is tribution 



Isopods were widely distributed over large portions of 

 the study area (Fig. 166). They were especially common 

 on the banks and in coastal regions. They were least 

 common in the deeper portion of the western Gulf of 

 Maine, in the vicinity of Nova Scotia, and on the conti- 

 nental shelf and rise. Densities between 10 and 50 indi- 



