Table 2.
Free amino acid concentrations 1 in juvenile mussels following low salinity exposure.
| Gill | Exposure at 20 ppt 2 | |||||
|---|---|---|---|---|---|---|
| Control | 24 h | 48 h | 72 h | F 3 | p | |
| Taurine | 357.3 ± 239.7 | 345.3 ± 36.6 (−3%) | 343.2 ± 46.9 (−4%) | 359.6 ± 45.0 (0%) | 0.02 | 0.995 |
| Betaine | 266.2 ± 163.2 | 277.0 ± 50.3 (+4%) | 275.3 ± 61.3 (+3%) | 306.1 ± 45.2 (+15%) | 0.171 | 0.914 |
| Glycine | 62.8 ± 45.4 | 17.6 ± 6.0 (−72%) | 14.8 ± 5.5 (−76%) | 22.7 ± 11.3 (−63%) | 4.48 | 0.018 |
| Homarine | 17.4 ± 8.3 | 13.3 ± 3.9 (−23%) | 7.7 ± 4.1 (−56%) | 16.3 ± 4.0 (−6%) | 3.21 | 0.051 |
| Alanine | 34.2 ± 30.3 | 22.2 ± 7.7 (−35%) | 23.5 ± 7.8 (−31%) | 24.0 ± 10.0 (−30%) | 0.54 | 0.665 |
| Mantle | ||||||
| Taurine | 238.2 ± 54.9 | 224.6 ± 27.7 (−6%) | 200.3 ± 61.8 (−15%) | 220.3 ± 45.1 (−8%) | 0.51 | 0.680 |
| Betaine | 243.3 ± 30.2 | 243.0 ± 50.9 (0%) | 266.2 ± 65.2 (+9%) | 255.3 ± 72.9 (+5) | 0.19 | 0.904 |
| Glycine | 81.5 ± 10.3 | 52.9 ± 13.5 (−35%) | 37.5 ± 38.1 (−53%) | 37.8 ± 23.9 (−54%) | 3.70 | 0.034 |
| Homarine | 34.2 ± 7.0 | 29.6 ± 7.6 (−13%) | 27.3 ± 13.7 (−20%) | 39.0 ± 15.8 (+14%) | 0.99 | 0.422 |
| Alanine | 80.4 ± 25.5 | 73.1 ± 23.6 (−9%) | 58.8 ± 65.0 (−27%) | 53.9 ± 53.0 (−33%) | 0.37 | 0.778 |
| Adductor | ||||||
| Taurine | 195.6 ± 38.1 | 216.3 ± 54.1 (+11%) | 263.8 ± 36.3 (+35%) | 198.1 ± 33.6 (+1%) | 2.93 | 0.065 |
| Betaine | 151.7 ± 20.3 | 177.7 ± 77.7 (+17%) | 213.7 ± 61.4 (+41%) | 158.6 ± 29.3 (+5%) | 1.39 | 0.281 |
| Glycine | 141.6 ± 51.7 | 137.4 ± 16.9 (−3%) | 110.3 ± 36.7 (−22%) | 100.7 ± 53.0 (−29%) | 1.13 | 0.365 |
| Homarine | 53.4 ± 19.7 | 57.8 ± 22.5 (+8%) | 48.3 ± 14.7 (−10%) | 65.4 ± 40.6 (+22%) | 0.38 | 0.768 |
| Alanine | 80.8 ± 24.3 | 66.1 ± 16.4 (−18%) | 58.6 ± 24.9 (−27%) | 63.3 ± 13.1 (−22%) | 1.11 | 0.373 |
1 Concentrations measured in µmol·g−1 dry weight ± SE; 2 Values in parentheses indicate the proportional change in the concentration of each individual amino acid, where decreases are highlighted in red; 3 The F and p-values in the columns, at right, correspond to separate univariate analyses testing the effect of salinity treatment for each amino acid within the MANOVA for each tissue type. Given multiple comparisons the critical value for each univariate test is set at a = 0.01.