TABLE 1. Regression equations relating shell size (mm) to biovolume.
|
Species |
Size (mm) vs. biovolume (ml) |
r |
|
Tawera gayi |
Ln Y = 3,21 Ln X - 9,24; X= shell length |
0.91 |
|
Trophon geversianus |
Ln Y= 2,29 Ln X – 5,41; X = shell width |
0.97 |
TABLE 2. Relative abundance of predators and their potential prey in different sites located on the Beagle Channel. Trophon geversianus specimens with drillholes were only found in site 1. In the other sites specimens with drillholes were always bivalves.
|
Sites |
This study (site 1) |
R.Ovando (site 2) |
Gable (70 km east) |
Ensenada (5 km east) |
|
Age |
ca. 4000 yr (Not dated) |
4425+/-55 |
4790+/-100 |
Modern |
|
Prey |
35% Trophon |
94% Tawera |
96,38% Tawera, Mytilus |
97,8% Mytilus |
|
Predator |
65% Trophon |
6% Trophon |
3,6% Trophon, Xymenopsis |
2,2% Trophon |
|
N |
20 |
180 |
138 |
141 |
|
Trophon Predation |
Intraguild |
Interguild |
Interguild |
Interguild |
|
Competition Regime |
High |
Low |
Low |
Low |
