FISHERY BULLETIN: VOL. 72, NO. 4 



Figure 6.^Reef-face habitat. Most of the fishes shown swimming at the base of the reef are Acanthurus leucopareius. 



The reef face shown here drops 8 to 10 m. 



Table 5. — The 10 fish species most frequently seen along trans- 

 ect lines in the reef-face habitat during the day. 



Outer Drop-Off Habitat 



At the rim of the outer drop-off, 50 to 600 m from 

 shore, where the sea floor falls abruptly from 

 about 25 m to much greater depths, the sea floor 

 generally is overgrown with the fingerlike form of 

 Pontes compressus, interspersed with massive 

 heads of P. pukoensis, bare basalt boulders, and 

 sand patches (Figure 7). The most striking charac- 

 teristic of this habitat, aside from the spectacular 

 way the sea floor falls away, is the large number of 



planktivorous fishes that abound in the water col- 

 umn. Obviously conditions for feeding on plank- 

 ton are especially well developed here. The fishes 

 listed in Table 6 '^ are characteristic of those seen 

 on the rim of the outer drop-off during the day. 



''Table 6 is based on data from four transects at four outer 

 drop-off sites — two at Palemano Point and two at Puuhonua 

 Point (see Figure 1). Total number of species observed on these 

 four transects: 78; mean number of individuals of all species for a 

 single transect: 478. 



Table 6. — The 10 fish species most frequently seen along trans- 

 ect lines in the outer drop-off habitat during the day. 



Rank Species 



No. times in 

 Relative top 10 of 



abundance individual 

 Index transects n = 4 



Mn making transect counts I follow/ed Gosline and Brock (1960) In 

 recognizing Chromis leucurus to Include two color forms. Further study 

 may show that two (or more) species are included here (see species 

 account for C. leucurus In this report) 



922 



