*2.1. Biometrics*

Biometrics of *P. noctiluca*, caught from March to June, are reported in Figure 1; while in Table S1, the summary output of the two-way ANOVA analysis performed on investigated parameters, such as length (cm), bell diameter (cm), and weight (g) of the wet mass, is reported.

For each dependent morphometric variable, the two-way ANOVA analysis pointed out statistically significant interactions (*p* < 0.05) between the two independent variables (namely, specimen's sex and sampling month) (Table S1).

Between March and April (2017), female organisms were characterized by length ranging between 10.6 and 13.0 cm (*p* > 0.05), and bell diameter between 8.8 and 9.9 cm (*p* > 0.05); while length and bell diameter of males were between 6.5 and 9.6 cm (*p* > 0.05) and 7.7 and8.6 cm (*p* > 0.05), respectively. Weight oscillated between 39.5 and 58.2 g for females (*p* < 0.05) and 37.0 and 54.7 g for male specimens (*p* < 0.05) (Figure 1).

Between May and June, minor lengths and bell diameters were recorded both for females (9.0–7.7 cm, *p* > 0.05, and 6.5–6.7 cm, *p* > 0.05, respectively) and males (7.1–7.7 cm, *p* > 0.05, and 7.2–7.5 cm, *p* > 0.05, respectively). Also, females, on average, had a lower weight distribution than males, with weights ranging from 25.7 to 31.9 g (*p* < 0.05) and from 31.7 to 31.8 g (*p* > 0.05), respectively (Figure 1).

Considering the different sampling periods, greater fluctuations of length, bell diameter and weight, were observed between March and April than June and May, both in female and male specimens. Additionally, from March–April to June–May, the investigated parameters were significantly reduced (*p* < 0.05) in female jellyfish. A significant reduction (*p* < 0.05) of wet mass was also observed in male jellyfish, but similar lengths (*p* > 0.05) and bell diameters (*p* > 0.05) were recorded throughout the sampling period.

Considering the sex specimens, in March, female and male medusae showed similar bell diameters (8.8 and 7.7 cm, *p* > 0.05) and weights (39.5 and 37.0 cm, *p* > 0.05) but significantly different lengths (13.0 and 7.2 cm, *p* < 0.05). In April and May, the trend changed as bell diameters of females and males were similar (9.9 and 8.6 cm, *p* > 0.05, and 6.5 and 7.2 cm, *p* > 0.05, respectively); while significantly different lengths (10.6 and 9.0 cm, *p* < 0.05, 9.0 and 7.1 cm, *p* < 0.05, respectively) and weights (58.2 and 54.7 g, *p* < 0.05, and 25.7 and 31.7 g, *p* < 0.05, respectively) were observed. Finally in June both female and male organisms showed similar lengths, bell diameters and masses (*p* > 0.05) (Figure 1).

**Figure 1.** Fresh weight (g), bell diameter (cm), and length (cm) of jellyfish samples collected per sex and month. Data are reported as mean ± standard deviation (*n* = 50). According to the four sampling periods, female (or male) jellyfish marked by different letters for a given biometric characteristic, differ significantly (*p* < 0.05 by post hoc Tukey's Honestly Significant Difference (HSD) test). According to sex specimens, female and male jellyfish marked by the asterisk for a specific parameter in the same sampling month differ significantly (*p* < 0.05 by post hoc Tukey's HSD test). F = female. M = male.

### *2.2. Gross Energy Contents*

The gross energy densities of female and male jellyfish bells and oral arms obtained by bomb calorimetry are outlined in terms of Kcal 100 g<sup>−</sup><sup>1</sup> on a dry weight (dw) basis (Figure 2). The two-way ANOVA analysis revealed that the interaction between specimen's sex and anatomical part (independent variables) was statistically significant (*p* < 0.05, Table S2). Overall, statistically significant differences were found independently of the considered body part (*p* < 0.05), as bell was characterized by higher energy content then oral arms, both in female and male medusae.

Additionally, considering the bell, statistically different energy values were detected between female and male specimens (*p* < 0.05). In fact, the sample from female bells showed the highest calorie value (621 Kcal 100 g<sup>−</sup>1), followed by the one from male bells (357 Kcal 100 g<sup>−</sup>1); whereas both male and female oral arms were characterized by inferior and nonsignificantly different calorie levels (174 and 151 Kcal 100 g<sup>−</sup>1, respectively, *p* > 0.05).

**Figure 2.** Gross energy densities of female and male jellyfish bells and oral arms. Data are reported as Kcal 100 g<sup>−</sup><sup>1</sup> on a dw basis, in terms of mean ± standard deviation (*n* = 3). Samples marked by different letters differ significantly (*p* < 0.05 by post hoc Tukey's HSD test).
