Stingray disc width and observed electric field that resulted in initiation of a feeding response by treatment
| . | N . | Mean disc width ±s.e.m. (mm) . | Disc width range (mm) . | Mean treatment resistivity ±s.e.m. (Ω cm) . | Median electric field ±s.e.m. (μV cm–1) . | Electric field range (μV cm–1) . |
|---|---|---|---|---|---|---|
| Treatment | ||||||
| IR0 | 10 | 252.1±8.4 | 218–308 | 2087±151.6 | 1.2±0.5 | 0.2–5.5 |
| IR15 | 9 | 247.6±3.7 | 230–265 | 41±0.4 | 0.01±0.002 | 0.002–0.02 |
| IR35 | 8 | 252.9±4.2 | 232–265 | 19±0.2 | 0.005±0.007 | 0.0006–0.06 |
| SJ0 | 10 | 283.8±8.2 | 244–339 | 1965±49.7 | 1.5±0.5 | 0.3–5.3 |
| SJ15 | 7 | 282.9±5.6 | 270–312 | 40±0.02 | 0.003±0.0007 | 0.002–0.007 |
| Combined treatments | ||||||
| FW | 20 | 268.0±6.8 | 218–339 | 2026±78.9 | 1.4±0.3 | 0.2–5.5 |
| BSW | 24 | 259.6±4.0 | 230–312 | 34±2.1 | 0.005±0.002 | 0.0006–0.06 |
| . | N . | Mean disc width ±s.e.m. (mm) . | Disc width range (mm) . | Mean treatment resistivity ±s.e.m. (Ω cm) . | Median electric field ±s.e.m. (μV cm–1) . | Electric field range (μV cm–1) . |
|---|---|---|---|---|---|---|
| Treatment | ||||||
| IR0 | 10 | 252.1±8.4 | 218–308 | 2087±151.6 | 1.2±0.5 | 0.2–5.5 |
| IR15 | 9 | 247.6±3.7 | 230–265 | 41±0.4 | 0.01±0.002 | 0.002–0.02 |
| IR35 | 8 | 252.9±4.2 | 232–265 | 19±0.2 | 0.005±0.007 | 0.0006–0.06 |
| SJ0 | 10 | 283.8±8.2 | 244–339 | 1965±49.7 | 1.5±0.5 | 0.3–5.3 |
| SJ15 | 7 | 282.9±5.6 | 270–312 | 40±0.02 | 0.003±0.0007 | 0.002–0.007 |
| Combined treatments | ||||||
| FW | 20 | 268.0±6.8 | 218–339 | 2026±78.9 | 1.4±0.3 | 0.2–5.5 |
| BSW | 24 | 259.6±4.0 | 230–312 | 34±2.1 | 0.005±0.002 | 0.0006–0.06 |
Treatment classifications (IR0, IR15, IR35, SJ0, SJ15) are created by combining the stingray capture location, the Indian River Lagoon (IR) or St Johns River (SJ), with the salinity at which they were tested, freshwater (0 p.p.t.), brackish water (15 p.p.t.) or full-strength seawater (35 p.p.t.). FW,freshwater; BSW, brackish–saltwater