Relationships between multilocus heterozygosity at allozyme loci and shell length were analysed in 1-year-old cohorts of Ostrea edulis (five populations, seven loci). In contrast with usual observations for marine bivalves, as well as previous studies on captive O. edulis, our results show: (i) a lack of significant heterozygote deficiency within populations and no differentiation in allele frequences among populations; (ii) no association between multilocus heterozygosity and size, although the statistical power is sufficient to detect regressions that explain as little as 5% variance in size. The lack of repeatability of multilocus heterozygosity–fitness correlations across species or across populations within one species has already been observed, and suggested to depend on the age of the sampled cohorts. However, variation in the breeding structure of the samples can also play a role. According to the `inbreeding' hypothesis for multilocus heterozygosity-fitness correlations, populations with very low inbreeding should lack both heterozygote deficiencies and multilocus heterozygosity-fitness correlations, consistent with the present results in oysters.

Six novel green extraction techniques were evaluated and optimized to extract pyrethrin from dried Dalmatian pyrethrum (Tanacetum cinerariifolium (Trevir./Sch.Bip.). This approach offers a promising natural alternative to conventional chemotherapeutics. Four methods are presented for the first time in this study: microwave-assisted extraction (MAE), high-voltage electric discharge (HVED) extraction, subcritical water extraction (SWE), and deep eutectic solvent (DES) extraction, together with supercritical CO₂ extraction (SC-CO₂) and ultrasound-assisted extraction (UAE), for pyrethrin extraction from Dalmatian pyrethrum. The study revealed that supercritical CO₂ extraction was the most effective method for extracting all six pyrethrins, yielding the highest total amount of 124.37 ng/mg. This approach offers a “natural” insecticide produced with a clean, environmentally friendly technology that can contribute to the development of sustainable and effective insecticide strategies that are in line with environmental safety and organic production standards. In addition, this research highlights the potential application of pyrethrins as antiparasitic agents, emphasizing their role in environmentally friendly and ecological practices.

Antibacterial resistance has become a major problem where new promising drugs are needed. The extracts obtained from marine invertebrates Mytilus galloprovincialis, Patella sp., Gibbula sp. and Arbacia lixula were tested against bacteria using the disc diffusion method. Citrobacter sp. from seawater and Paenibacillus sp., Bacillus sp. and Geobacillus sp. from soil were used as well as the reference bacterial strains Staphylococcus aureus NCTC 12981, S. aureus subsp. aureus Rosenbach ATCC 6538, Salmonella enterica subsp. enterica serovar Enteritidis ATCC 13076, Salmonella enterica subsp. enterica serotype Typhimurium NCTC 12023, Listeria monocytogenes ATCC 19111, Klebsiella aerogenes ATCC 13048 and Escherichia coli NCTC 12241. The most successful bacterial inhibitors, inhibiting 8 of 13 strains were extracts of M. galloprovincialis, Patella sp., Gibbula sp., Enteromorpha sp., C. sinuosa and U. lactuca, extract of A. lixula showed antibacterial activity against five bacteria, while extract of C. officinalis showed no antibacterial activity. These results indicate the potential of these marine organisms as a source of antibacterial compounds and may serve as a basis for further research and development of new antibacterial agents.