Specimens | Number | Refractive indices: Average (± SD) | ||
---|---|---|---|---|
Upper boundary | Lower boundary | Difference between the boundaries | ||
Rhopalaea sp. (fresh) | 11 | 1.3393 (±0.0006) | 1.3435 (±0.0017) | 0.0042 (±0.0016) |
Rhopalaea sp. (frozen–thawed) | 4 | 1.3396 (±0.0002) | 1.3434 (±0.0003) | 0.0038 (±0.0002) |
Thetys vagina (frozen–thawed) | 4 | Not available | 1.3416 (±0.0011) | 0.0023 (±0.0011)a |