vertical and horizontal burrowing, it was concluded that no pattern of burrow 

 gallery formation existed but that burrowing was a meandering extension of 

 past burrows. 



Depth of sediment penetration likewise correlates with worm size (Figure 

 20-6). The lower vertical Hmit of burrows for first -year worms (up to 0.1 g wet 

 weight) is 2-3 cm beneath the sediment-water interface. Second-year worms 

 (up to 0.4 g) limit burrowing tc 7-8 cm. Three-year old worms (up to 1 g) may 

 burrow as deep as 14-15 cm. N. incisa of all sizes may be found near the 







2- 



^ 4 



o 



ct 6 

 cm 



CD 



^ 8 



O 



a 10 



UJ 

 Q 



LU 



14 



WORM WEIGHT (g WET WT) 

 .2 .4 .6 .8 



1.0 



6 ? 



99 



Figure 20-6. Nephtys incisa Mean Depth of Burrowing in 

 Relation to Worm Size. 



311 



