3.2.1. Embryo Photomotor Response

The red pigment crystal dramada produced by *S. cuboideum* was the only compound shown to have significant bioactivity. Exposure to concentrations of 10.7 and 23.2 μM was associated with hyperactive tail bending in the excitatory phase (*p* = 0.043 and 0.022, respectively), and in the case of 23.2 μM also in the baseline phase (*p* = 0.007). In contrast, at 50 μM an absence of any activity was observed in both the excitatory and baseline phases, with *p* values of 0.024 and 0.022, respectively.

## 3.2.2. Larval Photomotor Response

Dramada was also the only tested compound that showed any significant effect on larval photomotor response, though all tested compounds were modestly bioactive. Many were associated with effects during the light phase of testing, with the exception of one concentration of the red pigment dramada. Aniline was shown to have a significant hyper effect on photomotor response behaviors in the light interval at 2.32 μM (*n* = 27, *p* < 0.01), at 5 μM (*n* = 30, *p* < 0.01), at 10.7 μM (*n* = 26, *p* < 0.01), and at 23.2 μM (*n* = 27, *p* < 0.01). Xylindein from *C. aeruginosa* was associated with a hyperactive response on LPR in light at ~5 mM or 2.8 mg/mL (*n* = 15, *p* < 0.01), and a hypoactive response at ~10.7 mM or 5.7 mg/mL (*n* = 14, *p* < 0.01). Finally, dramada from *S. cuboideum* at 2.32 mM showed a hypoactive effect in both dark (*n* = 26, *p* < 0.01) and light (*n* = 26, *p* < 0.01) conditions, and a hypoactive effect in light at 5 mM (*n* = 23, *p* < 0.01) and 10 mM (*n* = 23, *p* < 0.01). Dramada also did not have enough animals remaining at 120 hpf to allow for analysis, unlike xylindein and aniline which showed no significant effects at the highest concentration. These abnormalities seen in dramada and impure xylindein from *C. aeruginosa* were modest in comparison to other known compounds that have a major effect on LPR in the lighted phase [42]. In addition, the lack of association with differences in the dark phase is unusual, suggesting that the effect may be at the level of detection and spurious. The control compound used for comparison, aniline, showed similar moderate levels of abnormalities.
