Food Preference of Algivorous Invertebrates — Leighton 
111 
TABLE 1 
Consistency in Results of Experimental Feedings of Seven Algal Foods to Invertebrates 
INVERTEBRATE SPECIES 
NUMBER OF 
EXPERIMENTS 
NUMBER OF 
INDIVIDUALS 
EMPLOYED IN 
EACH EXPT. 
TOTAL NUMBER 
OF DIFFERENT 
GROUPS 
EMPLOYED 
COEFFICIENT OF 
CONCORDANCE* 
w = 
Aplysia calif ornica 
12 
2 
6 
0.59 
Astraea undosa 
10 
5 
5 
0.79 
Haliotis corrugata 
10 
3 
3 
0.51 
Haliotis fulgens 
10 
4 
6 
0.47 
Haliotis rufescens 
10 
4 
5 
0.58 
Lytechinus anamesus 
10 
10 
8 
0.60 
Norrisia norrisii 
11 
10 
5 
0.41 
Pugettia producta 
10 
2 
9 
0.77 
Strongylocentrotus franciscanus 
11 
5 
8 
0.58 
Strongylocentrotus purpmatus 
10 
10 
7 
GL58 
Taliepus nuttallii 
12 
2 
5 
0.51 
* This coefficient is a measure of the degree of agreement between sets of repetitive experimental results (see text). Values 
may range from 0.0 to 1.0, the higher figures indicating a higher degree of agreement. All values in this table are significant at 
better than the 0.1% level. 
TABLE 2 
Decigrams of Different Algae Consumed by 10 Adult Strongylocentrotus purpmatus 
in 24-hour Experimental Feeding Periods 
EXPERIMENT 
Macrocystis 
Egregia 
Laminaria 
Eisenia 
Pterygophora 
Cystoseira 
Gigartina 
1 
91 
63 
97 
51 
60 
1 
96 
2 
72 
50 
83 
70 
79 
10 
81 
3 
62 
28 
88 
87 
65 
2 
49 
4 
84 
30 
14 
11 
8 
0 
20 
5 
73 
43 
31 
3 
13 
0 
15 
6 
76 
38 
74 
45 
20 
0 
0 
7 
96 
27 
8 
0 
30 
2 
36 
8 
58 
46 
54 
0 
0 
8 
75 
9 
72 
12 
83 
9 
16 
1 
26 
10 
71 
14 
28 
24 
3 
0 
51 
Mean 
75.5 
35.1 
56.0 
30.0 
29.4 
2.4 
44.9 
