The scyphozoan Pelagia noctiluca has potential value for research and a wide variety of industrial applications. However, its holoplanktonic life cycle makes it difficult to maintain a permanent stock in aquaculture, unlike the continuous supply of newly-released ephyrae from jellyfish species with a benthic life stage. We investigated optimal feeding conditions for the captive breeding of P. noctiluca, monitoring total body diameter, morphological development, survival rate, and instantaneous growth rate. Diets of different items encapsulated in gelatin or non-motile prey were not suitable for successful growth of the early stages (ephyra and metaephyra), whereas rotifers were a sufficient food source for healthy growth. Fertilized eggs from sexually-mature jellyfish were obtained at 84.5 ± 2.1 and 87.0 ± 9.9 days post-fecundation in the presence and absence of gelatinous prey (Aurelia sp.), respectively. In contrast with the general consensus, we demonstrate that the incorporation of medusivorous prey was not essential for proper growth and closure of P. noctiluca life cycle. Instead, we recommend the inclusion of white shrimps (Acetes sp.) for the formation and maturation of gonads and production of eggs. Instantaneous growth rates (57.0% d-1), the highest reported to date for this species in captive conditions, were higher during the early stages. A third generation of cultured P. noctiluca was obtained for the first time (169 – 179 experimental days), demonstrating the durability of the culture, providing permanent stock and halving the production time of mature individuals compared to previous studies. Finally, we validated the use of captive-bred specimens through quantification of the hemolytic area after the sting process using the tentacle skin blood agarose assay methodology.

La Réunion, one of the three Mascarene islands located in the Indian Ocean, remained devoid of inhabitants until it was first colonized by the French in the middle of the 17th century. The continuous flow of foreign-born slaves and immigrant workers from Africa, India, Southeast Asia, and China to work on coffee and sugar cane plantations led to the island becoming a melting pot of people of multiple ethnic origins. To establish the impact of the different incoming ethnic groups on the present Reunionese gene pool, we have sequenced both hypervariable regions I and II of the mitochondrial DNA molecule, the 9 bp COII/tRNA(Lys) deletion, and four SNPs located in the coding region in a total of 41 samples of the general population, and a further 18 STRs and 35 SNPs on the Y chromosome in 26 of these samples. Our results show that there was a strong sexual bias (asymmetrical gene flow) in the peopling of La Réunion, where admixture events were mainly between male settlers and females from the incoming slave groups. Most of the Y-chromosome gene pool is of European/Middle Eastern ancestry (85%), whereas the mtDNA gene pool is mainly of Indian and East Asian ancestry (70%). The absence of genetic diversity within these two major components of the mtDNA gene pool suggests these populations may have witnessed strong founder effects during the colonization process.

Background Acne pathophysiology includes a complex interaction among inflammatory mediators, hyperseborrhea, alteration of keratinization and follicular colonization by Propionibacterium acnes. Aims To describe the impact of the exposome on acne and how photoprotection can improve outcomes. Methods A narrative review of the literature was carried out; searches with Google Scholar and Pubmed from January 1992 to November 2022 were performed. The keywords used were “acne,” “sunscreens,” “photoprotection,” “cosmetics,” “cosmeceuticals,” “pathogenesis,” “etiology,” “exposome,” “sunlight,” “stress,” “lack of sleep,” “diet,” “postinflammatory hyperpigmentation,” “pollution,” “exposome,” “ultraviolet radiation,” and “visible light.” Results Environmental factors such as solar radiation, air pollution, tobacco consumption, psychological stress, diverse microorganisms, nutrition, among others, can trigger or worsen acne. Solar radiation can temporarily improve lesions. However, it can induce proinflammatory and profibrotic responses, and produce post‐inflammatory hyperpigmentation and/or post‐inflammatory erythema. While photoprotection is widely recommended to acne patients, only four relevant studies were found. Sunscreens can significantly improve symptomatology or enhance treatment and can prevent post‐inflammatory hyperpigmentation. Furthermore, they can provide camouflage and improve quality of life. Based on acne pathogenesis, optimal sunscreens should have emollient, antioxidant and sebum controlling properties. Conclusions The exposome and solar radiation can trigger or worsen acne. UV light can induce post‐inflammatory hyperpigmentation/erythema, and can initiate flares. The use of specifically formulated sunscreens could enhance adherence to topical or systemic therapy, camouflage lesions (tinted sunscreens), decrease inflammation, and reduce the incidence of post‐inflammatory hyperpigmentation/erythema.

Anemonia viridis is an abundant and widely distributed temperate sea anemone that can form dense congregations of individuals. Despite the potential severity of its sting, few detailed cases have been reported. We report a case of a severe toxic reaction following an A. viridis sting in a 35-year-old oceanographer. She developed severe pain, itching, redness, and burning sensation, which worsened one week after treatment with anti-inflammatories, antihistamines and corticosteroids. Prompted by this event, and due to the insufficient risk prevention, lack of training for marine-environment users, and lack of research into sting-specific first-aid protocols, we evaluated the cnidocyst response to five different compounds commonly recommended as rinse solutions in first-aid protocols (seawater, vinegar, ammonia, baking soda, and freshwater) by means of the Tentacle Solution Assay. Vinegar and ammonia triggered an immediate and massive cnidocyst discharge after their application and were classified as activator solutions. Baking soda and freshwater were also classified as activator solutions, although with a lower intensity of discharge. Only seawater was classified as a neutral solution and therefore recommended as a rinse solution after A. viridis sting, at least until an inhibitory solution is discovered.

Rhizostoma pulmo is a widely distributed scyphozoan in the Mediterranean Sea. Their stings result mainly in erythema, small vesicles, or/and pain, and cause a high number of bathers to seek assistance from first-aid services during the summer season. Despite the threat that jellyfish stings represent to public health, there is disagreement in the scientific community on first-aid protocols, with the dispute largely centered around the effectiveness of vinegar. In the present research, we investigated the effect of commonly used rinse solutions on nematocyst discharge in R. pulmo and the effect of vinegar on three more scyphozoans (Aurelia sp., Cassiopea sp., and Rhizostoma luteum). Scented ammonia, vinegar, and acetic acid triggered nematocyst discharge in R. pulmo. Vinegar also caused nematocyst discharge in Aurelia sp., Cassiopea sp., and R. luteum. In contrast, seawater, baking soda, freshwater, urine, and hydrogen peroxide were considered neutral solutions that did not induce nematocyst discharge. These results indicate that the use of vinegar, acetic acid, or commercial products based on these compounds is counterproductive. Their use can worsen pain and discomfort caused not only by R. pulmo stings but also by those of any scyphozoan. The use of seawater is recommended for cleaning the R. pulmo sting site until an inhibitor solution that irreversibly prevents nematocyst discharge is discovered.