*2.4. Phenolic Compounds*

As mentioned in the Materials and Methods section, at an initial stage of analysis, samples underwent two different preparation procedures, based on the use of PBS and methanol, respectively. Once the method was optimized, the first procedure was preferred, due to better analytical performance in terms of speed and efficiency. The UV spectrophotometric analysis determined the total phenolic content in dried bells and oral arms of male and female organisms in terms of μg of gallic acid

equivalents (GAE) g- on a dw basis (Figure 4). According to the two-way ANOVA test, the interaction of specimen's sex and anatomical part was statistically significant (*p* < 0.05, Table S4). In general, phenolic compounds were more abundant in oral arms rather than in bells (1892–2126 μg GAE g<sup>−</sup><sup>1</sup> vs. 914–1303 μg GAE g<sup>−</sup>1, respectively, *p* < 0.05). Considering the same anatomical part (bell or arms), a statistically significant difference (*p* < 0.05) was also determined between the phenolic contents of male and female specimens: 1303.32 μg GAE g<sup>−</sup><sup>1</sup> vs. 914.22 μg GAE g<sup>−</sup>1; and 2126.56 μg GAE g<sup>−</sup><sup>1</sup> vs. 1892.69 μg GAE g<sup>−</sup>1, in males and females, respectively.

**Figure 4.** Total phenolic content (μg GAE g<sup>−</sup>1) determined in male and female jellyfishes' bell and oral arms. Data are expressed as mean ± standard deviation (*n* = 3), on a dw basis. Samples marked by different letter differ significantly (*p* < 0.05 by post hoc Tukey's HSD test).
