Find which species was more numerous
Table1. Mark-recapture Largemouth bass data from the Des Plaines River.
|
Size (cm) |
Number of individuals day 1 |
Number of individuals day 2 |
Population density estimate |
|
|
Unmarked |
Marked |
|||
|
< 10 |
73 |
64 |
22 |
570 |
|
10-20 |
35 |
28 |
13 |
|
|
20-30 |
20 |
22 |
18 |
|
|
> 30 |
6 |
4 |
2 |
|
|
Total |
134 |
118 |
55 |
|
Using these data, estimate the density (number/hectare) of each size class plus the overall density. [Note: 1 hectare = 10,000 m2.]
Bluntnose minnow
Complete the following table
Table 2. Mark-recapture Bluntnose minnow data from the Des Plaines River.
|
Size (cm) |
Number of individuals day 1 |
Number of individuals day 2 |
Population density estimate |
|
|
Unmarked |
Marked |
|||
|
< 3 |
252 |
174 |
63 |
|
|
3-6 |
196 |
145 |
54 |
|
|
6-9 |
177 |
132 |
58 |
|
|
> 9 |
34 |
26 |
11 |
|
|
Total |
659 |
477 |
186 |
|
1. Which species was more numerous is the Des Plaines River? How much more abundant?
2. Based on the data, which species grows to a larger size?
3. Which species do you think is the prey and which is the predator? Why?