Fig 1.
Representative adult tolerance to H2O2 exposure.
Representative individuals from Sippewissett MA (top row: clone line MA B1; bottom row: clone line MA A1) during exposure to 0.0005% H2O2 (A-D) or control conditions (E-F) over 7 days. After a week, the majority of the clonal lines showed severe disfigurement and loss of tentacles (as in B), but some clonal lines appeared relatively resistant to H2O2 exposure (as in D).
Fig 2.
Tentacle number during 14-day exposure to H2O2 or control conditions.
Data for 15 N. vectensis clone lines are shown. In all graphs, days of exposure are given along the X-axis, and tentacle numbers are shown on the Y-axis. Data from the control condition are shown in black, while data from H2O2 exposure are shown in colored lines. The number of individuals tested under control conditions and H2O2 exposure is provided for each clonal line (n = #/#). Statistically significant differences between H2O2 and control conditions on a given day are indicated using asterisks (* = p<0.05; ** = p<0.005). Error bars depict the standard deviations for each mean.
Fig 3.
Mean tentacle counts during H2O2 exposure.
For each of 15 N. vectensis clonal lines, mean tentacle number for 4–11 individuals is plotted against days of exposure to 0.0005% H2O2. Thin vertical lines depict standard errors.
Fig 4.
Representative regenerating N. vectensis during H2O2 exposure.
An adult N. vectensis from New Jersey, approximately 1 cm in length (A), was bisected through the body column (at the site of the arrow) using a scalpel. The cut divided the anemone into (B) an oral fragment bearing the mouth and tentacles (tn) and an aboral fragment bearing the foot, or physa (phy). The scalpel scored the bottom of the plastic petri dish in which the bisection was performed (arrow). Following bisection, the regenerating aboral fragment was exposed to 0.00025% H2O2 over a period of 14 days. Seven days after bisection (C), the aboral fragment had developed 10 tentacles. The tentacle tips are numbered in the photo. By day 14 (D), 12 tentacles had developed. In panel D, the pharynx (pha) and several of the eight complete mesenteries (mes) are visible.
Fig 5.
Tentacle counts in regenerating N. vectensis.
Regeneration ability as measured by mean tentacle number over time (n = 5–11) during exposure to 0.00025% H2O2 or control conditions. In all graphs, the number of days since the anemones were bisected is indicated along the X-axis, and tentacle number is shown on the Y-axis. Data from the control condition are shown in black, while data from H2O2 exposure are shown in colored lines. The number of individuals tested under control conditions and H2O2 exposure is provided for each clonal line (n = #/#). Statistically significant differences between H2O2 and control conditions on a given day are indicated using asterisks (* = p<0.05; ** = p<0.005).
Fig 6.
Mean tentacle counts during regeneration under H2O2 exposure.
For each of 14 N. vectensis clonal lines, mean tentacle number for 5–11 individuals (see Fig 6) is plotted against days of exposure to 0.00025% H2O2. Thin vertical lines depict standard deviations.
Table 1.
Hydrogen peroxide levels measured in aquatic environments.
Table 2.
Effects of hydrogen peroxide exposure on marine invertebrates.