Composition and Distribution of Macrobenthic Invertebrate Fauna 



93 



NEW \ NEW .- \ \ 



JERSEY ', YORK/ N \ NEW / 



\ \ HAMPSHIRE y 



v6fi»TS 



GRAMS 

 PER SQUARE METER 



NEMATODA 



Figure 63 



Geographic distribution of Nematoda: A — number of specimens per square meter of 

 bottom; B — biomass in grams per square meter of bottom. 



all other bottom tvpes yielded relatively moderate den- 

 sities (1 to 3 individuals/rrr). Average biomass was small 

 (0.01 g/m 2 orless) in all sediment types (Tables 18, 19; 

 Fig. 66). 



The frequency of occurrence of nematodes was mod- 

 erate (12 to 13%) in gravel, sand-silt, and silt-clay but 

 was low (4 and 5%) in sand and till (Table 20). 



Relation to Water Temperature 



Nematodes occurred at all temperature ranges except 

 the highest, 20°-23.9°C (Tables 21, 22; Fig. 67). Their 

 numerical density was greatest (2.0 to 4.3 individuals/ 

 m 2 ) in the narrow to intermediate temperature ranges 

 (0°-11.9°C) and declined drastically (0.2 and 0.7/m 2 ) 

 in the broader ranges. 



