The reproductive biology of the invasive blue crab Callinectes sapidus was studied in the Thermaikos Gulf (Northwest Aegean Sea, Eastern Mediterranean). In the two-year survey, 5698 (2897♂/2801♀) crabs were caught with the use of fyke nets. Total sex ratio (♂/♀) reached equality (1.03:1). The female blue crab exhibited a protracted reproductive period. Mature and ovigerous females exhibit short migratory movements from estuarine and inshore waters, where the population mostly congregates (0–3 m), and move to slightly deeper waters (1–3 m) up to 9 m for spawning. A total of 340 ovigerous females were caught. Their number varied both spatially and temporally; they were observed for a 7-month period (April to October) with a clear peak in July–August and at a 3 m depth gradient corresponding to ≈60% of the total number of ovigerous females caught in both years. Size at first sexual maturity (CW₅₀) was estimated at 113.1 mm CW. Average fecundity was ≈790,000 eggs. Experimental trawling showed that inshore waters (<1 m) in the estuaries serve as nursery areas for juveniles. Defining the spatiotemporal and bathymetrical distribution of ovigerous females in any invaded coastal habitat could be considered key information for the implementation of a management policy for the species.

The reproductive biology of the invasive blue crab Callinectes sapidus was studied in the Thermaikos Gulf (Northwest Aegean Sea, Eastern Mediterranean). In the two-year survey 5,698 (2,897♂/ 2,801♀) crabs were caught with the use of fyke nets. Total sex ratio (♂/♀) reached equality (1.03:1). The female blue crab exhibited a protracted reproductive period. Mature and ovigerous females exhibit short migratory movements from estuarine and inshore waters, where the population mostly congregates (0-3 m), and move to slightly deeper waters (1-3 m) up to 9 m for spawning. A total of 340 ovigerous females were caught. Their number varied both spatially and temporally; they were observed for a 7-month period (April to October) with a clear peak in July - August and at a 3 m depth gradient corresponding to ≈60% of the total number of ovigerous females caught in both years. Size at first sexual maturity (CW50) was estimated at 113.1 mm CW. Average fecundity was ≈790,000 eggs. Experimental trawling showed that inshore waters (<1 m) in the estuaries serve as nursery areas for juveniles. Defining the spatiotemporal and bathymetrical distribution of ovigerous females in any invaded coastal habitat could be considered key information for the implementation of a management policy for the species.

Microalgae display remarkable resilience to harsh environments, partly through the biosynthesis of diverse secondary metabolites. Cyanobacteria and red algae are well known to produce mycosporine-like amino acids (MAAs)—low-molecular-weight, water-soluble UV-absorbing compounds with anti-inflammatory, anticancer, and antimicrobial activities. By contrast, green microalgae typically lack detectable MAAs under standard conditions, and their responses under abiotic stress remain poorly characterized. Here, we investigated the freshwater green microalga Jaagichlorella luteoviridis grown under three stressors (salinity, heat, and UV) and assessed MAA induction. High-performance liquid chromatography (HPLC) revealed that stressed cultures accumulated multiple MAAs, whereas untreated controls showed no such accumulation. All stress treatments (UV, salinity, and heat) produced a substantial increase in peak intensity at 323–350 nm, whereas the control samples showed significantly lower absorption in this region. We also optimized an MAA extraction protocol suitable for “green” downstream applications in the pharmaceutical, nutraceutical, and cosmeceutical sectors and formulated an emulsion showing preliminary positive results and exhibiting an increased SPF index from 3.60 (control) to 3.78 when 0.2% MAA extract was added. Transcriptomic profiling against a reference genome revealed stress-specific differential gene expression and overexpression of specific genes of the MAA pathway, like ArioC and AroM/Aro1 SAM methyltransferases, thus identifying candidate targets for engineering enhanced MAA production. Given market demand for environmentally friendly and safe bioactives, microalgae represent a promising source of these valuable molecules.