MEYER ET AL : AMERICAN SAND LANCE FROM THE GULF OF MAINE 



Figure 6. — School of sand lance encountered on Provincetown slope. Note lateral view of sand lance leaving the bottom to join school 



above. 



celerated to one side or split to avoid the divers at 

 the part of the school closest to the divers. The 

 forward portion of the school continued on in its 

 original direction, while the rear portion gener- 

 ally reversed direction. These avoidance maneu- 

 vers were made at about 70-120 cm/s, over double 

 the original undisturbed speed, and lasted for only 

 a few seconds before the divided sections re- 

 grouped and slowed down to their original speed. 

 Feeding schools were observed in midwater and 

 near the surface, but not on the bottom. 



Kiihlmann and Karst (1967) recorded the es- 

 cape speed of larger sand lance to be 300-500 cm/s 

 for at least a few seconds. During our study, there 

 were many occasions when the swimming speed 

 appeared to be >120 cm/s, but the actual speed 

 was not calculated. 



Behavior Within and Near the Ocean Floor 



Sand lance were found in substrates conducive 

 to burrowing, such as clean sandy bottoms, sand 

 bottoms with crushed shells, and fine-graveled 

 bottoms. Substrates of mud, mud/silt, medium to 

 coarse gravel, and rock/boulder were avoided. This 

 preference for loose porous substrate facilitates 

 entry and exit and may relate to a sufficient supply 

 of dissolved oxygen within at least the first few- 

 centimeters of interstitial water. Oxygen is con- 

 tinually replenished by tidal currents of 32-47 

 cm/s (0.62-0.91 kn) measured at 1 m above the 

 bottom on Stellwagen Bank (Padan 1977). 



Sand lance usually disappear into the bottom in 

 small groups. The initial penetrating angle was 

 estimated as 60°-75° from the horizontal and con- 



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