Tuning in to multiple predators: conflicting demands for shell morphology in a freshwater snail.
- Department of Biology
- Division aquatic ecology
2. Snails were subjected to four treatments: tench (Tinca tinca), signal crayfish (Pacifastacus leniusculus), a combination of tench and signal crayfish and no predators (control). Shell shape, crushing resistance and shell thickness were quantified. We also analyzed whether shape or shell thickness contributes most to crushing resistance.
3. Chemical cues from the fish induced a rounder shell shape in R. balthica, a thicker shell and a higher crushing resistance, whereas crayfish chemical cues had no effect on shell morphology, shell thickness or crushing resistance. Shell shape contributed more to crushing resistance than shell thickness.
4. The combined predator treatment showed an intermediate response between the fish and crayfish treatments. Shell roundness was reduced compared to the fish treatment, but the reduced crushing resistance that comes with a less rounded shell was compensated by an increased investment in extra shell material, exceeding that of the fish treatment.
5. Our study extends previous studies of multipredator effects on phenotypically plastic freshwater snails by showing that the snails are able to fine tune different elements of morphology to counter predator specific foraging modes.
- Radix balthica
- phenotypic plasticity
- inducible defence
- complementary traits
- chemical cues
- ISSN: 0046-5070