Results of general linear models testing the size-scaling of oxygen consumption and shell mass of Helix aspersa snails from control versus size-selected lines, and in fast-growth versusslow-growth phases
| . | Metabolism*×body mass . | . | Metabolism*×flesh mass . | . | Shell mass†×flesh mass . | . | |||
|---|---|---|---|---|---|---|---|---|---|
| Factor . | F . | P . | F . | P . | F . | P . | |||
| Control line | |||||||||
| Growth phase | 4.78(1,92) | 0.0313 | 5.28(1,94) | 0.024 | 2.19(1,93) | 0.14 | |||
| Body size | 134.82(1,92) | 0.000001 | 112.38(1,94) | 0.000001 | 244.83(1,93) | 0.000001 | |||
| Growth phase×body size | 1.42(1,92) | 0.24 | 0.52(1,94) | 0.47 | 7.44(1,93) | 0.0076 | |||
| Size-selected line | |||||||||
| Growth phase | 2.14(1,89) | 0.15 | 1.58(1,89) | 0.21 | 1.10(1,89) | 0.30 | |||
| Body size | 146.86(1,89) | 0.000001 | 125.55(1,89) | 0.000001 | 303.02(1,89) | 0.000001 | |||
| Growth phase×body size | 4.11(1,89) | 0.0457 | 3.00(1,89) | 0.0867 | 3.48(1,89) | 0.0653 | |||
| Fast-growth phase | |||||||||
| Line | 0.003(1,97) | 0.96 | 0.62(1,98) | 0.43 | 0.43(1,97) | 0.51 | |||
| Body size | 852.46(1,97) | 0.000001 | 730.91(1,98) | 0.000001 | 1208.56(1,97) | 0.000001 | |||
| Line×body size | 3.00(1,97) | 0.0867 | 4.11(1,98) | 0.0453 | 3.08(1,97) | 0.0826 | |||
| Slow-growth phase | |||||||||
| Line | 0.005(1,84) | 0.94 | 0.001(1,85) | 0.98 | 0.08(1,85) | 0.78 | |||
| Body size | 75.86(1,84) | 0.000001 | 71.47(1,85) | 0.000001 | 187.00(1,85) | 0.000001 | |||
| Line×body size | 0.003(1,84) | 0.95 | 0.01(1,85) | 0.92 | 0.06(1,85) | 0.80 | |||
| . | Metabolism*×body mass . | . | Metabolism*×flesh mass . | . | Shell mass†×flesh mass . | . | |||
|---|---|---|---|---|---|---|---|---|---|
| Factor . | F . | P . | F . | P . | F . | P . | |||
| Control line | |||||||||
| Growth phase | 4.78(1,92) | 0.0313 | 5.28(1,94) | 0.024 | 2.19(1,93) | 0.14 | |||
| Body size | 134.82(1,92) | 0.000001 | 112.38(1,94) | 0.000001 | 244.83(1,93) | 0.000001 | |||
| Growth phase×body size | 1.42(1,92) | 0.24 | 0.52(1,94) | 0.47 | 7.44(1,93) | 0.0076 | |||
| Size-selected line | |||||||||
| Growth phase | 2.14(1,89) | 0.15 | 1.58(1,89) | 0.21 | 1.10(1,89) | 0.30 | |||
| Body size | 146.86(1,89) | 0.000001 | 125.55(1,89) | 0.000001 | 303.02(1,89) | 0.000001 | |||
| Growth phase×body size | 4.11(1,89) | 0.0457 | 3.00(1,89) | 0.0867 | 3.48(1,89) | 0.0653 | |||
| Fast-growth phase | |||||||||
| Line | 0.003(1,97) | 0.96 | 0.62(1,98) | 0.43 | 0.43(1,97) | 0.51 | |||
| Body size | 852.46(1,97) | 0.000001 | 730.91(1,98) | 0.000001 | 1208.56(1,97) | 0.000001 | |||
| Line×body size | 3.00(1,97) | 0.0867 | 4.11(1,98) | 0.0453 | 3.08(1,97) | 0.0826 | |||
| Slow-growth phase | |||||||||
| Line | 0.005(1,84) | 0.94 | 0.001(1,85) | 0.98 | 0.08(1,85) | 0.78 | |||
| Body size | 75.86(1,84) | 0.000001 | 71.47(1,85) | 0.000001 | 187.00(1,85) | 0.000001 | |||
| Line×body size | 0.003(1,84) | 0.95 | 0.01(1,85) | 0.92 | 0.06(1,85) | 0.80 | |||
Growth rate accelerates with age in the fast-growth phase; it decelerates with age in the slow-growth phase. Oxygen consumption scaled with whole body mass of snails (body size including shell mass) or against snail flesh mass(body size without shell mass); shell mass scaled against flesh mass. Snail line and growth phase were treated as fixed factors; degrees of freedom for F statistics are given in brackets. Data were transformed with decimal logarithms prior to analysis
Metabolism measured as oxygen consumption (μl h–1)
shell mass (g)